As filed with the U.S. Securities and Exchange Commission on April 30, 2020

Registration No. 333-236379

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

AMENDMENT No. 3

TO

FORM S-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

APERGY CORPORATION

(Exact name of registrant as specified in its charter)

2445 Technology Forest Blvd

Building 4, 12th Floor

The Woodlands, Texas 77381

Telephone: (281) 403-5772

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Julia Wright

Senior Vice President, General Counsel and Secretary

2445 Technology Forest Blvd

Building 4, 12th Floor

The Woodlands, Texas 77381

Telephone: (281) 403-5772

(Name, address, including zip code, and telephone number, including area code, of agent for service)

With copies to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable following the effective date of this registration statement and satisfaction or waiver of all other conditions to the consummation of the Exchange Offer and Merger described herein.

If the securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, check the following box.  ☐

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards pursuant to Section 7(a)(2)(B) of the Securities Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act or until the registration statement shall become effective on such date as the U.S. Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

Apergy Corporation (“Apergy”) is filing this registration statement on Form S-4 (Registration No. 333-236379) to register the shares of its common stock, par value $0.01 per share (“Apergy common stock”), that will be issued in the merger (the “Merger”) of Athena Merger Sub, Inc., a Delaware corporation (“Merger Sub”), which is a wholly owned subsidiary of Apergy, with and into ChampionX Holding Inc., a Delaware corporation (“ChampionX”), whereby the separate corporate existence of Merger Sub will cease and ChampionX will continue as the surviving corporation and become a wholly owned subsidiary of Apergy. ChampionX is a wholly owned subsidiary of Ecolab Inc. (“Ecolab”) that was incorporated specifically for the purpose holding the ChampionX Business (as defined in the prospectus included in this registration statement). Prior to the Merger, Ecolab will transfer certain assets, liabilities and entities to ChampionX or its subsidiaries. In exchange therefor, Ecolab will receive shares of ChampionX common stock and a cash payment, and the shares of ChampionX common stock will be distributed to Ecolab stockholders as described below.

Ecolab will offer its stockholders the option to exchange all or a portion of their shares of Ecolab common stock for shares of ChampionX common stock in the Exchange Offer (as defined in the prospectus included in this registration statement). If the Exchange Offer is consummated, but the Exchange Offer is not fully subscribed because fewer than all of the shares of ChampionX common stock owned by Ecolab are exchanged, the remaining shares of ChampionX common stock owned by Ecolab would be distributed on a pro rata basis to Ecolab stockholders whose shares of Ecolab common stock remain outstanding after consummation of the Exchange Offer. If the Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions (as defined herein) have otherwise been satisfied), all shares of ChampionX common stock owned by Ecolab will be distributed on a pro rata basis to Ecolab stockholders in a spin-off. After the distribution of the shares of ChampionX common stock in a split-off or spin-off (in the event the Exchange Offer is not fully subscribed or is terminated), the shares of ChampionX common stock will immediately be converted into shares of Apergy common stock in the Merger.

Apergy has filed a definitive proxy statement that relates to the special meeting of stockholders of Apergy to approve the issuance of shares of Apergy common stock in the Merger. In addition, ChampionX filed a registration statement on Form S-4 and Form S-1 (Registration No. 333-236380) to register the offer of shares of common stock, par value $0.01 per share, which shares will be distributed to Ecolab’s stockholders pursuant to a split-off and/or a spin-off in connection with the Transactions, which shares of ChampionX common stock will be immediately converted into shares of Apergy common stock in the Merger.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

PRELIMINARY — SUBJECT TO COMPLETION, DATED APRIL 30, 2020

PROSPECTUS—OFFER TO EXCHANGE

ECOLAB INC.

Offer to Exchange all Shares of Common Stock of

CHAMPIONX HOLDING INC.

Which are Owned by Ecolab Inc.

and Will Be Converted Into Shares of Common Stock of

APERGY CORPORATION

for

Outstanding Shares of Common Stock of Ecolab Inc.

Ecolab Inc. (“Ecolab”) is offering to exchange all shares of common stock, par value $0.01 per share (“ChampionX common stock”), of ChampionX Holding Inc. (“ChampionX”) owned by Ecolab for outstanding shares of common stock of Ecolab (“Ecolab common stock”) that are validly tendered and not properly withdrawn. The terms and conditions of this Exchange Offer (as defined below) are described in this prospectus, which you should read carefully. None of Ecolab, ChampionX, any of their respective directors or officers or any of their respective representatives makes any recommendation as to whether you should participate in this Exchange Offer. You must make your own decision after reading this prospectus and consulting with your advisors. This Exchange Offer is voluntary. If you would like to keep all of your shares of Ecolab common stock, you do not need to take any action.

Ecolab’s obligation to exchange shares of ChampionX common stock for shares of Ecolab common stock is subject to the satisfaction of certain conditions, including conditions to the consummation of the Transactions (as defined below), which include approval by the stockholders of Apergy Corporation (“Apergy”) of the issuance of shares of common stock of Apergy (“Apergy common stock”) in the Merger (as defined below).

The transactions contemplated by the Merger Agreement (as further described in “The Transaction Agreements—The Merger Agreement”) and the Separation Agreement (as further described in “The Transaction Agreements—The Separation Agreement”), referred to in this prospectus collectively as the Transactions, are being undertaken to transfer the ChampionX Business (as defined below) from Ecolab to Apergy. The aggregate value of the consideration to be paid to Ecolab stockholders with respect to the ChampionX Business in the Transactions is estimated, as of April 24, 2020, to be approximately $1.02 billion in value of Apergy common stock (calculated based on the closing price on the New York Stock Exchange (the “NYSE”) of Apergy common stock as of April 24, 2020) issuable to Ecolab stockholders that participate in this Exchange Offer.

Immediately following the consummation of this Exchange Offer, Athena Merger Sub, Inc., a Delaware corporation and wholly owned subsidiary of Apergy (“Merger Sub”), will be merged with and into ChampionX, whereby the separate corporate existence of Merger Sub will cease and ChampionX will continue as the surviving corporation and a wholly owned subsidiary of Apergy (the “Merger”). In the Merger, each outstanding share of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock equal to the Merger Exchange Ratio (as defined in “The Transactions—The Merger—Calculation of the Merger Consideration”). In addition, ChampionX will authorize the issuance of a number of shares of ChampionX common stock such that the total number of shares of ChampionX common stock outstanding immediately prior to the Distribution (as defined below) will be that number that results in the Merger Exchange Ratio equaling one. As a result, each share of ChampionX

common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into one share of Apergy common stock in the Merger. The aggregate number of shares of Apergy common stock to be issued in the Merger by Apergy is expected to result in pre-Merger holders of shares of ChampionX common stock and ChampionX employees collectively owning approximately 62% of the issued and outstanding shares of Apergy common stock on a fully-diluted basis after giving effect to the Merger and pre-Merger holders of Apergy common stock or equity-based awards of Apergy owning approximately 38% of the issued and outstanding shares of Apergy common stock on a fully-diluted basis. ChampionX common stock will not be transferred to participants in this Exchange Offer; such participants will instead receive shares of Apergy common stock in the Merger. No trading market currently exists for ChampionX common stock. You will not be able to trade shares of ChampionX common stock before they are converted into shares of Apergy common stock in the Merger. In addition, there can be no assurance that shares of Apergy common stock, when issued in the Merger, will trade at the same prices at which shares of Apergy common stock traded prior to the Merger.

The value of Ecolab common stock and ChampionX common stock for purposes of establishing the exchange ratio for this Exchange Offer will be determined by Ecolab by reference to the simple arithmetic average of the daily volume-weighted average prices (“VWAP”) on each of the Valuation Dates (as defined below) of Ecolab common stock and Apergy common stock on the NYSE. The “Valuation Dates” will be the last three full trading days ending on and including the third trading day preceding the expiration date of this Exchange Offer, as it may be voluntarily extended. Based on an expiration date of June 3, 2020, the Valuation Dates are expected to be May 27, 2020, May 28, 2020 and May 29, 2020. See “Exchange Offer—Terms of This Exchange Offer.”

This Exchange Offer is designed to permit you to exchange your shares of Ecolab common stock for shares of ChampionX common stock at a 10% discount to the per-share value of Apergy common stock, calculated as set forth in this prospectus, subject to the upper limit described below. For each $100 of your Ecolab common stock accepted for exchange in this Exchange Offer, you will receive approximately $111.11 of ChampionX common stock, subject to an upper limit of 24.6667 shares of ChampionX common stock per share of Ecolab common stock. This Exchange Offer does not provide for a minimum exchange ratio. See “Exchange Offer—Terms of This Exchange Offer.” If the upper limit is in effect, then the exchange ratio will be fixed at that limit. IF THE UPPER LIMIT IS IN EFFECT, AND UNLESS YOU PROPERLY WITHDRAW YOUR SHARES, YOU WILL RECEIVE LESS (AND YOU COULD RECEIVE MUCH LESS) THAN $111.11 OF CHAMPIONX COMMON STOCK FOR EACH $100 OF ECOLAB COMMON STOCK THAT YOU TENDER.

The indicative exchange ratio that would have been in effect following the official close of trading on the NYSE on April 29, 2020 (the second to last trading day before the date of this prospectus), based on the daily VWAPs of Ecolab common stock and Apergy common stock on April 27, 2020, April 28, 2020 and April 29, 2020, would have provided for 21.6285 shares of ChampionX common stock to be exchanged for every share of Ecolab common stock accepted for exchange. The value of ChampionX common stock issued and, following the Merger, the value of Apergy common stock received may not remain above the value of Ecolab common stock tendered following the expiration of this Exchange Offer.

THIS EXCHANGE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:01 A.M., NEW YORK CITY TIME, ON JUNE 3, 2020, UNLESS THIS EXCHANGE OFFER IS EXTENDED OR TERMINATED. SHARES OF ECOLAB COMMON STOCK TENDERED PURSUANT TO THIS EXCHANGE OFFER MAY BE WITHDRAWN AT ANY TIME PRIOR TO THE EXPIRATION OF THIS EXCHANGE OFFER.

In reviewing this prospectus, you should carefully consider the risk factors beginning on page 40 of this prospectus.

We Are Not Asking You for a Proxy and You are Requested Not To Send Us a Proxy.

Neither the U.S. Securities and Exchange Commission (the “SEC”) nor any state securities regulator has approved or disapproved of the securities described in this prospectus or determined if this prospectus is accurate or adequate. Any representation to the contrary is a criminal offense.

The date of this prospectus is                 , 2020.

The final exchange ratio used to determine the number of shares of ChampionX common stock that you will receive for each share of your Ecolab common stock accepted for exchange in this Exchange Offer will be announced by press release no later than 9:00 a.m., New York City time, on the second to last full trading day prior to the expiration date. At such time, the final exchange ratio will be available at www.championxexchangeoffer.com and from the information agent for this Exchange Offer at the toll-free number provided on the back cover of this prospectus. Ecolab will announce whether the upper limit on the number of shares that can be received for each share of Ecolab common stock tendered and accepted for exchange will be in effect, through www.championxexchangeoffer.com and by press release, no later than 9:00 a.m., New York City time, on the second to last full trading day prior to the expiration date. Commencing after the close of trading on the third trading day of this Exchange Offer, indicative exchange ratios (calculated in the manner described in this prospectus) will also be available on that website and from the information agent at the toll-free number provided on the back cover of this prospectus.

This prospectus provides information regarding Ecolab, ChampionX, Apergy, this Exchange Offer and the Merger. Ecolab common stock is listed on the NYSE under the symbol “ECL.” Apergy common stock is listed on the NYSE under the symbol “APY.” On April 29, 2020, the last reported sale price of Ecolab common stock on the NYSE was $197.58 per share, and the last reported sale price of Apergy common stock on the NYSE was $10.68 per share. The market prices of Ecolab common stock and of Apergy common stock will fluctuate prior to the completion of this Exchange Offer and thereafter and may be higher or lower at the expiration date of this Exchange Offer than the prices set forth above. No trading market currently exists for ChampionX common stock. ChampionX has not applied for listing of ChampionX common stock on any exchange.

If this Exchange Offer is consummated but is not fully subscribed because less than all the shares of ChampionX common stock owned by Ecolab are exchanged the remaining shares of ChampionX common stock owned by Ecolab will be distributed to Ecolab stockholders whose shares of Ecolab common stock remain outstanding after the consummation of this Exchange Offer pursuant to a pro rata distribution (a “clean-up spin-off”). Any Ecolab stockholder who validly tenders (and does not properly withdraw) shares of Ecolab common stock that are accepted for exchange in this Exchange Offer will with respect to such shares waive their rights to receive, and forfeit any rights to, shares of ChampionX common stock distributed in the clean-up spin-off. This prospectus covers all shares of ChampionX common stock offered by Ecolab in this Exchange Offer and all shares of ChampionX common stock that may be distributed by Ecolab in a spin-off (including the clean-up spin-off) to holders of shares of Ecolab common stock. If this Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), Ecolab intends to distribute all shares of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab. See “Exchange Offer—Distribution of ChampionX Common Stock Remaining After This Exchange Offer.”

Following the consummation of this Exchange Offer, in the Merger, Merger Sub will be merged with and into ChampionX, whereby the separate corporate existence of Merger Sub will cease and ChampionX will continue as the surviving corporation and a wholly owned subsidiary of Apergy. In the Merger, each outstanding share of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock equal to the Merger Exchange Ratio. ChampionX will authorize the issuance of a number of shares of ChampionX common stock such that the total number of shares of ChampionX common stock outstanding immediately prior to the Distribution will be that number that results in the Merger Exchange Ratio equaling one. As a result, each share of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into one share of Apergy common stock in the Merger. Ecolab currently expects that approximately 122.0 million shares of ChampionX common stock will be available in this Exchange Offer.

Ecolab’s obligation to exchange shares of ChampionX common stock for Apergy common stock is subject to the conditions listed under “Exchange Offer—Conditions to Consummation of This Exchange Offer,” including the satisfaction of conditions to the Merger, which include Apergy stockholder approval of the issuance of Apergy common stock in connection with the Merger, and other conditions.

TABLE OF CONTENTS

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ANNEXES

Annex A – Opinion of Centerview Partners LLC

Annex B – Opinion of Lazard Frères & Co. LLC

This prospectus incorporates by reference important business and financial information about Ecolab and Apergy from documents filed with the SEC that have not been included in or delivered with this prospectus and have not been incorporated by reference unless explicitly stated. This information is available without charge at the website that the SEC maintains at www.sec.gov, as well as from other sources. See “Where You Can Find Additional Information; Incorporation by Reference.” You also may ask any questions about this Exchange Offer or request copies of the Exchange Offer documents and the other information incorporated by reference in this prospectus, without charge, upon written or oral request to Ecolab’s information agent, Georgeson, located at 1290 Avenue of the Americas, 9th Floor, New York, NY 10104 or at the telephone number 866-857-2624. In order to receive timely delivery of the documents, you must make your requests no later than May 26, 2020.

If you participate in the Ecolab stock fund through the Ecolab Savings Plans, you may ask questions about this Exchange Offer with respect to the plans, without charge, upon written or oral request to the trustee of the trust established under the plans, Fidelity Management Trust Company, located at 245 Summer Street, Boston, MA 02109 or at the telephone number 800-835-5091.

iii

All information contained or incorporated by reference in this prospectus with respect to Apergy, Merger Sub and their respective subsidiaries, as well as information on Apergy after the consummation of the Transactions, has been provided by Apergy. All other information contained or incorporated by reference in this prospectus with respect to Ecolab, ChampionX or their respective subsidiaries, and with respect to the terms and conditions of this Exchange Offer, has been provided by Ecolab.

This prospectus is not an offer to exchange and it is not a solicitation of an offer to buy any shares of Ecolab common stock, Champion common stock or Apergy common stock in any jurisdiction in which the offer, sale or exchange is not permitted. Non-U.S. stockholders should consult their advisors in considering whether they may participate in this Exchange Offer in accordance with the laws of their home countries and, if they do participate, whether there are any restrictions or limitations on transactions in the shares of ChampionX common stock that may apply in their home countries. Ecolab, ChampionX and Apergy cannot provide any assurance about whether such limitations may exist. See “Exchange Offer—Certain Matters Relating to Non-U.S. Jurisdictions” for additional information about limitations on this Exchange Offer outside the United States.

iv

SELECTED DEFINITIONS

Certain abbreviations and terms used in the text and notes are defined as follows:

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QUESTIONS AND ANSWERS ABOUT THIS EXCHANGE OFFER AND THE TRANSACTIONS

The following are brief answers to some of the common questions that stockholders of Ecolab may have regarding the transactions contemplated by the Merger Agreement and the Separation Agreement, which provide for, among other things, the Separation, the Distribution and the Merger. For more detailed information about the matters discussed in these questions and answers, see “The Transactions” beginning on page 150 and “The Transaction Agreements” beginning on page 193. These questions and answers are not meant to be a substitute for the information contained in the remainder of this prospectus, and this information is qualified in its entirety by the more detailed descriptions and explanations contained elsewhere in this prospectus. Stockholders of Ecolab are urged to read this prospectus in its entirety prior to making any decision. You should pay special attention to the “Risk Factors” beginning on page 41 and “Cautionary Statement Regarding Forward-Looking Statements” beginning on page 66.

Questions and Answers about this Exchange Offer

The legal limitations described above could prevent certain holders of Ecolab common stock from participating in this Exchange Offer, which could cause this Exchange Offer to be undersubscribed.

Non-U.S. stockholders should consult their advisors in considering whether they may participate in this Exchange Offer in accordance with the laws of their home countries and, if they participate, whether there are any restrictions or limitations on transactions in the shares of Ecolab common stock, shares of ChampionX common stock or shares of Apergy common stock that may apply in their home countries. None of Ecolab, Apergy or ChampionX can provide any assurance about whether such limitations may exist. See “Exchange Offer—Certain Matters Relating to Non-U.S. Jurisdictions” for additional information about limitations on this Exchange Offer outside the United States.

All holders who are tendering shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to their Ecolab Savings Plans accounts or Ecolab Stock Purchase Plan accounts should follow the special instructions provided to them by or on behalf of their applicable plan administrator. Such participants may direct the applicable plan trustee or agent to tender all, some or none of the shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to their Ecolab Savings Plans accounts or Ecolab Stock Purchase Plan accounts, subject to certain limitations. To allow sufficient time for the tender of shares of Ecolab common stock (or units in respect of shares of

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Ecolab common stock) by the trustee of the applicable Ecolab Savings Plans or the agent of the Ecolab Stock Purchase Plan, tendering holders must provide the tabulator for the Ecolab Savings Plans or the agent for the Ecolab Stock Purchase Plan with the requisite instructions by the deadline specified in the special instructions provided to them, unless this Exchange Offer is extended. If this Exchange Offer is extended, and if administratively feasible, the deadline for receipt of the holder’s direction also may be extended.

The upper limit would represent a 21% discount for ChampionX common stock based on the average of the daily VWAPs of Ecolab common stock and Apergy common stock on the NYSE on April 27, 2020, April 28, 2020, and April 29, 2020 (the last three full trading days ending on the second to last full trading day prior to commencement of this Exchange Offer). Ecolab set this upper limit to ensure that an unusual or unexpected drop in the trading price of Apergy common stock, relative to the trading price of Ecolab common stock, would not result in an unduly high number of shares of ChampionX common stock being exchanged for each share of Ecolab common stock accepted for exchange in this Exchange Offer.

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In addition, for purposes of illustration, a table that indicates the number of shares of ChampionX common stock that you would receive per share of Ecolab common stock, calculated on the basis described above

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and taking into account the upper limit, assuming a range of averages of the daily VWAP of Ecolab common stock and Apergy common stock on the Valuation Dates, is provided in “Exchange Offer—Terms of This Exchange Offer.”

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An exception to proration can apply to stockholders (other than participants in the Ecolab Savings Plans) who beneficially own “odd lots,” that is, fewer than 100 shares of Ecolab common stock. Such beneficial holders of Ecolab common stock who validly tender all of their shares will not be subject to proration.

In all other cases, proration for each tendering stockholder will be based on (i) the proportion that the total number of shares of Ecolab common stock to be accepted for exchange bears to the total number of shares of Ecolab common stock validly tendered and not properly withdrawn and (ii) the number of shares of Ecolab common stock validly tendered and not properly withdrawn by that stockholder (and not on that stockholder’s aggregate ownership of shares of Ecolab common stock). Any shares of Ecolab common stock not accepted for exchange as a result of proration will be returned to tendering stockholders promptly after the final proration factor is determined.

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Ecolab may waive any of the conditions to this Exchange Offer prior to the expiration of this Exchange Offer. For a description of the material conditions precedent to this Exchange Offer, including satisfaction or waiver of the conditions to the Transactions, the receipt of Apergy stockholder approval of the Share Issuance Proposal, and other conditions, see “Exchange Offer—Conditions to Consummation of This Exchange Offer.” ChampionX has no right to waive any of the conditions to this Exchange Offer. Apergy has no right to waive any of the conditions to this Exchange Offer (however, Apergy does have the right to waive certain conditions relating to the Merger).

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The rules applicable to the Ecolab Savings Plans and the Ecolab Stock Purchase Plan are described separate notices, which will be made available to the Ecolab Savings Plan and Ecolab Stock Purchase Plan participants. Ecolab Savings Plan and Ecolab Stock Purchase Plan participants should consult this additional notice together with this prospectus in deciding whether or not to participate in this Exchange Offer with respect to their Ecolab Savings Plan and Ecolab Stock Purchase Plan shares (or units in respect of shares of Ecolab common stock).

For specific instructions about how to tender the shares of Ecolab common stock attributable to your account, see “Exchange Offer—Terms of This Exchange Offer—Procedures for Tendering.”

If you do not elect to exchange some or all of the shares of Ecolab common stock attributable to your account for shares of ChampionX common stock (in each case, or units in respect of shares), you may still receive shares of ChampionX common stock (or units in respect of shares of ChampionX common stock) in the clean-up spin-off (in the event this Exchange Offer is not fully subscribed or is terminated) in respect of the shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) attributable to your account. Upon the closing of the Merger, any shares of ChampionX common stock attributable to your account (or units in respect of shares of ChampionX common stock) will be converted into shares of Apergy common stock (or units in respect of shares of Apergy common stock).

After the closing of the Merger, the plan design may be changed or the independent fiduciary responsible for evaluating the propriety of investment options under the applicable Ecolab Savings Plan may conclude that the applicable Ecolab Savings Plan will no longer maintain an Apergy stock fund, in which case you may be required to sell the shares of Apergy common stock attributable to your account (or units in respect of shares of Apergy common stock) and reallocate the sale proceeds to one or more of the other investment options within the applicable Ecolab Savings Plan.

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The Separation, the Distribution and the Merger are described in more detail in “The Transactions” and elsewhere in this prospectus.

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“Equity Award Adjustment Ratio” means (A) the closing trading price per share of Ecolab common stock divided by (B) the closing trading price per share of Apergy common stock, in both cases as determined immediately prior to the Separation effective time.

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All Ecolab equity awards, other than those described above, will be retained by Ecolab. Ecolab may equitably adjust its retained equity awards in accordance with the terms and conditions of the applicable Ecolab equity plan and award agreement in the event of a clean-up spin-off or, if this Exchange Offer is terminated, a distribution by Ecolab of the outstanding shares of ChampionX common stock to Ecolab stockholders on a pro rata basis.

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For a discussion of the circumstances under which the termination fee is payable by Apergy or Apergy is required to partially reimburse Ecolab’s expenses, see “The Transaction Agreements—The Merger Agreement—Termination Fee and Expenses Payable in Certain Circumstances” beginning on page 209.

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SUMMARY

The following summary contains certain information described in more detail elsewhere in this prospectus. To better understand the proposed Transactions, and for a more complete description of the legal terms of the Separation, the Distribution and the Merger, you should read this entire prospectus carefully, as well as those additional documents to which we refer you. See also “Where You Can Find Additional Information; Incorporation by Reference.”

The Companies (See “Information About Apergy and Merger Sub,” “Information About Ecolab,” and “Information About the ChampionX Business” beginning on page 84)

Apergy Corporation

2445 Technology Forest Blvd

Building 4, 12th Floor

The Woodlands, Texas 77381

Telephone: (281) 403-5772

Apergy Corporation, which we refer to as Apergy, a Delaware corporation, is a leading provider of highly engineered equipment and technologies that help companies drill for and produce oil and gas safely and efficiently around the world. Apergy’s products provide efficient functioning throughout the lifecycle of a well, from drilling to completion to production. For more information on Apergy, see “Information About Apergy and Merger Sub.”

Athena Merger Sub, Inc.

c/o Apergy Corporation

2445 Technology Forest Blvd

Building 4, 12th Floor

The Woodlands, Texas 77381

Telephone: (281) 403-5772

Athena Merger Sub, Inc., which we refer to as Merger Sub, a wholly owned subsidiary of Apergy, was incorporated in the State of Delaware on December 16, 2019 for the purposes of merging with and into ChampionX in the Merger. Merger Sub has not carried on any activities other than in connection with the Merger Agreement. For more information on Merger Sub, see “Information About Apergy and Merger Sub.”

ChampionX Holding Inc.

11177 South Stadium Drive

Sugar Land, Texas 77478

Telephone: (281) 632-6500

ChampionX Holding Inc., which we refer to as ChampionX, a wholly owned subsidiary of Ecolab, was incorporated in the State of Delaware on September 18, 2019 to own and operate Ecolab’s ChampionX Business. In connection with the Transactions, among other things, Ecolab will cause specified assets and liabilities used in the ChampionX Business to be conveyed to ChampionX in exchange for the issuance to Ecolab of ChampionX common stock and the Cash Payment. For more information on the ChampionX Business, see “Information About the ChampionX Business.”

Ecolab Inc.

1 Ecolab Place

St. Paul, Minnesota 55102

Telephone: (800) 232-6522

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Ecolab Inc., which we refer to as Ecolab, is a Delaware corporation incorporated in 1924. With 2019 sales of $14.9 billion, Ecolab is the global leader in water, hygiene and energy technologies and services that protect people and vital resources. Ecolab delivers comprehensive programs, products and services to promote safe food, maintain clean environments, optimize water and energy use, and improve operational efficiencies for customers in the food, healthcare, energy, hospitality and industrial markets in more than 170 countries around the world. Ecolab’s cleaning and sanitizing programs and products, and pest elimination services, support customers in the foodservice, food and beverage processing, hospitality, healthcare, government and education, retail, textile care and commercial facilities management sectors. Ecolab’s products and technologies are also used in water treatment, pollution control, energy conservation, oil production and refining, steelmaking, papermaking, mining and other industrial processes. For more information on Ecolab, see “Information About Ecolab.”

The Transactions (See “The Transactions” beginning on page 150)

On December 18, 2019, Ecolab, ChampionX, Apergy and Merger Sub entered into the Merger Agreement and Ecolab, ChampionX and Apergy entered into the Separation Agreement, pursuant to which Apergy will combine with Ecolab’s ChampionX Business. As a result of and immediately following the Transactions, ChampionX equityholders will own, in the aggregate, approximately 62% of the issued and outstanding Apergy common stock on a fully diluted basis and Apergy equityholders will own, in the aggregate, approximately 38% of the issued and outstanding Apergy common stock on a fully diluted basis. Ecolab stockholders that do not participate in this Exchange Offer will retain the shares of Ecolab common stock that they held prior to the Merger.

In connection with the Transactions, Apergy, Ecolab and ChampionX have entered into the Separation Agreement to effect the Separation and Distribution and have entered into or will enter into several other agreements to provide a framework for their relationship after the Distribution and the Merger. These agreements provide for the allocation between Ecolab, on the one hand, and ChampionX and Apergy, on the other hand, of certain assets, liabilities and obligations related to the ChampionX Business and will govern the relationship between Ecolab, ChampionX and Apergy after the Distribution and the Merger. In connection with the Transactions:

In addition, in connection with the Transactions, ChampionX will enter into a credit agreement with respect to a $537 million senior secured term loan credit facility to finance the Cash Payment to Ecolab and otherwise pay certain expenses in connection with the Transactions. Also, in connection with the Transactions, Apergy entered into an amendment to its existing credit agreement to, among other things, increase its revolving commitments thereunder by a principal amount up to $150 million.

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For a more complete discussion of the agreements related to the Transactions, see “The Transaction Agreements” and “Additional Agreements Related to the Separation, the Distribution and the Merger.”

Overview (See “The Transactions—Transaction Sequence” beginning on page 151)

Below is a step-by-step list illustrating the sequence of material events relating to the Separation, the Distribution and the Merger. Each of these events is discussed in more detail elsewhere in this prospectus. Apergy and Ecolab anticipate that the Separation, Distribution and Merger will occur in the following order:

Step 1: At or prior to the date of the Distribution (described in Step 3 below), Ecolab, ChampionX and certain of each of their subsidiaries will engage in a series of actions, which may include transfers of securities, formation of new entities or other actions, to effect an internal restructuring. The separation of the ChampionX Business from the other businesses of Ecolab pursuant to the Separation Agreement is referred to as the Separation. In connection with the Separation, ChampionX will (a) issue to Ecolab any additional shares of ChampionX common stock required such that the number of shares of ChampionX common stock held by Ecolab shall be equal to the number of shares required to effect the Distribution (described in Step 3 below), and (b) make the Cash Payment.

Step 2: On the Distribution Date (described in Step 3 below), to the extent not previously effected pursuant to Step 1, (a) Ecolab and certain Ecolab subsidiaries will transfer to ChampionX or a ChampionX designee certain assets related to the ChampionX Business and certain liabilities related to the ChampionX Business, and (b) if needed, ChampionX and certain ChampionX subsidiaries will transfer to Ecolab or an Ecolab designee assets excluded from the ChampionX Business and liabilities excluded from the ChampionX Business.

Step 3: On the closing date of the Merger, Ecolab will distribute 100% of the shares of ChampionX common stock to Ecolab stockholders participating in this Exchange Offer. If this Exchange Offer is consummated, but this Exchange Offer is not fully subscribed because fewer than all shares of ChampionX common stock owned by Ecolab are exchanged, the remaining shares of ChampionX common stock owned by Ecolab would be distributed in the clean-up spin-off to Ecolab stockholders whose shares of Ecolab common stock remain outstanding after consummation of this Exchange Offer. If this Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), Ecolab intends to distribute all shares of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab. See “The Transactions—The Separation and the Distribution—The Distribution.” The date on which the Distribution occurs is referred to as the Distribution Date.

The Exchange Offer agent will hold, for the account of the relevant Ecolab stockholders, the book-entry authorizations representing all of the outstanding shares of ChampionX common stock, pending the consummation of the Merger. Shares of ChampionX common stock will not be able to be traded during this period.

Step 4: In the Merger, Merger Sub will be merged with and into ChampionX, with ChampionX surviving as a wholly owned subsidiary of Apergy. In the Merger, each outstanding share of ChampionX common stock (except for shares of ChampionX common stock held by Ecolab, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock such that ChampionX equityholders will own approximately 62% of the issued and outstanding Apergy common stock on a fully diluted basis and Apergy equityholders will own, in the aggregate, approximately 38% of the issued and outstanding Apergy common stock on a fully diluted basis.

Step 5: The Exchange Offer agent will distribute to ChampionX stockholders shares of Apergy common stock in the form of a book-entry authorization and cash in lieu of fractional shares (if any) in accordance with the terms of the Merger Agreement.

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Set forth below are diagrams that graphically illustrate, in simplified form, the existing corporate structure of the parties to the Transactions, the corporate structure of the parties immediately following the Distribution but before the Merger, and the final corporate structure immediately following the consummation of the Merger.

Existing Structure

Structure Following the Separation and the Distribution but Before the Merger

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Structure Following the Merger

The Separation and the Distribution (See “The Transactions—The Separation and the Distribution” beginning on page 153)

The Separation

As part of the Separation and immediately prior to the Distribution, to the extent not previously effected pursuant to an internal restructuring, (a) Ecolab and certain Ecolab subsidiaries will transfer to ChampionX certain assets related to the ChampionX Business and certain liabilities related to the ChampionX Business, and (b) ChampionX and certain ChampionX subsidiaries will transfer to Ecolab or an Ecolab designee assets excluded from the ChampionX Business and liabilities excluded from the ChampionX Business, in order to separate the ChampionX Business from Ecolab’s other businesses prior to the Distribution.

The Distribution—Exchange Offer and Split-Off

On the closing date of the Merger, Ecolab will distribute 100% of the shares of ChampionX common stock to Ecolab stockholders participating in this Exchange Offer. In this Exchange Offer, Ecolab will offer its stockholders the option to exchange all or a portion of their shares of Ecolab common stock for shares of ChampionX common stock. In the event this Exchange Offer is not fully subscribed, Ecolab will distribute the remaining shares of ChampionX common stock owned by Ecolab in the clean-up spin-off on a pro-rata basis to Ecolab stockholders whose shares of Ecolab common stock remain outstanding after consummation of this Exchange Offer.

Any Ecolab stockholder who validly tenders (and does not properly withdraw) shares of Ecolab common stock that are accepted for exchange in this Exchange Offer will with respect to such shares waive their rights to receive, and forfeit any rights to, shares of ChampionX common stock distributed in the clean-up spin-off. If there is a clean-up spin-off, the Exchange Offer agent will calculate the exact number of shares of ChampionX common stock owned by Ecolab that will not be exchanged in this Exchange Offer and to be distributed on a pro rata basis, and the number of shares of Apergy common stock into which the remaining shares of ChampionX

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common stock will be converted in the Merger will be transferred to the relevant Ecolab stockholders (after giving effect to the consummation of this Exchange Offer) as promptly as practicable thereafter. If this Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), Ecolab intends to distribute all shares of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab.

The Exchange Offer agent will hold, for the account of the relevant Ecolab stockholders, the book-entry authorizations representing all of the outstanding shares of ChampionX common stock pending the consummation of the Merger. ChampionX common stock will not be traded during this period.

The Merger (See “The Transactions—The Merger” beginning on page 154)

Immediately after the Distribution, pursuant to and in accordance with the terms and conditions of the Merger Agreement, Merger Sub will merge with and into ChampionX whereby the separate corporate existence of Merger Sub will cease and ChampionX will survive the Merger as a wholly owned subsidiary of Apergy. After the Merger, Apergy will continue its existence as a separately traded public company, owning the combined businesses of Apergy and ChampionX.

The Merger Agreement provides that, at the effective time of the Merger, each issued and outstanding share of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock equal to the Merger Exchange Ratio. The Merger Exchange Ratio is calculated under the Merger Agreement such that immediately following the Merger, ChampionX equityholders will own, in the aggregate, approximately 62% of the issued and outstanding Apergy common stock on a fully diluted basis and Apergy equityholders will own, in the aggregate, approximately 38% of the issued and outstanding Apergy common stock on a fully diluted basis. In addition, ChampionX will authorize the issuance of a number of shares of ChampionX common stock such that the total number of shares of ChampionX common stock outstanding immediately prior to the Distribution will be that number that results in the Merger Exchange Ratio equaling one. Apergy currently expects to issue approximately 127.6 million shares of Apergy common stock to ChampionX equityholders in connection with the Merger.

No fractional shares of Apergy common stock will be issued pursuant to the Merger. All fractional shares of Apergy common stock that a ChampionX stockholder would otherwise be entitled to receive as a result of the Merger (after such fractional shares are aggregated with all other fractional shares that would be issued to such holder) will be paid in cash the dollar amount (rounded to the nearest whole cent), after deducting any required withholding taxes, on a pro rata basis, without interest, determined by multiplying such fraction by the closing price of a share of Apergy common stock on the NYSE on the last business day prior to the date on which the Merger becomes effective.

Terms of This Exchange Offer (See “Exchange Offer—Terms of This Exchange Offer” beginning on page 68)

Ecolab is offering holders of shares of Ecolab common stock the opportunity to exchange their shares (or, for participants in the Ecolab Savings Plans, shares or units in respect of shares) for ChampionX common stock. You may tender all, some or none of your shares of Ecolab common stock. This prospectus and related documents are being sent to persons who directly held shares of Ecolab common stock on May 1, 2020 and brokers, banks and similar persons whose names or the names of whose nominees appear on Ecolab’s stockholder list or, if applicable, who are listed as participants in a clearing agency’s security position listing for subsequent transmittal to beneficial owners of shares of Ecolab common stock. This prospectus and related documents are also being sent to participants in the Ecolab Savings Plans whose plan accounts were invested in Ecolab common stock on April 24, 2020, and also persons who acquired shares of Ecolab common stock through the Ecolab Stock Purchase Plan.

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Ecolab common stock validly tendered and not properly withdrawn will be accepted for exchange at the exchange ratio determined as described in “Exchange Offer—Terms of This Exchange Offer,” on the terms and subject to the conditions and limitations described below, including the proration provisions.

Ecolab will promptly return any shares of Ecolab common stock that are not accepted for exchange following the expiration of this Exchange Offer and the determination of the final proration factor, if any, described below. After the expiration of this Exchange Offer, shares accepted for exchange by Ecolab may not be withdrawn; provided, however, that such shares may be withdrawn at any time after the expiration of 40 business days from the commencement of this Exchange Offer if this Exchange Offer has not then been consummated.

For the purposes of illustration, the table below indicates the number of shares of ChampionX common stock that you would receive per share of Ecolab common stock you validly tender, calculated on the basis described in “Exchange Offer—Terms of This Exchange Offer” and taking into account the upper limit, assuming a range of averages of the daily VWAP of Ecolab common stock and Apergy common stock on the Valuation Dates. The first row of the table below shows the indicative calculated per-share value of Ecolab common stock, the indicative calculated per-share value of ChampionX common stock and the indicative exchange ratio that would have been in effect (and the corresponding indicative calculated value ratio) following the official close of trading on the NYSE on April 29, 2020 based on the daily VWAPs of Ecolab common stock and Apergy common stock on April 27, 2020, April 28, 2020, and April 29, 2020. The table also shows the effects of a 15% increase or decrease in either or both the calculated per-share value of Ecolab common stock and the calculated per-share value of ChampionX common stock based on changes relative to the values as of April 29, 2020.

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For example, if the calculated per-share value of Ecolab common stock was $210.31 (the highest closing price for Ecolab common stock on the NYSE during the three-month period ending on the second to last full trading day prior to commencement of this Exchange Offer) and the calculated per-share value of ChampionX common stock was $3.02 (the lowest closing price for Apergy common stock on the NYSE during that three-month period), the value of ChampionX common stock, based on the Apergy common stock price, received for shares of Ecolab common stock accepted for exchange would be approximately $35 for each $100 of Ecolab common stock accepted for exchange.

Extension; Termination; Amendment

This Exchange Offer, and your withdrawal rights, will expire at 12:01 a.m., New York City time, on June 3, 2020, unless this Exchange Offer is extended or terminated. You must tender your shares of Ecolab common stock prior to this time if you want to participate in this Exchange Offer. Ecolab may extend, terminate or amend this Exchange Offer as described in this prospectus.

Any such extension, termination or amendment will be followed as promptly as practicable by public announcement thereof by Ecolab, which, in the case of an extension, will be made no later than 9:00 a.m., New York City time, on the next business day after the previously-scheduled expiration date.

Conditions to Consummation of This Exchange Offer

Ecolab’s obligation to exchange shares of ChampionX common stock for shares of Ecolab common stock is subject to the conditions listed under “Exchange Offer—Conditions to Consummation of This Exchange Offer,” including the satisfaction of conditions to the Transactions and other conditions. These conditions include:

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For a description of the material conditions precedent to the Transactions, see “The Transaction Agreements—The Merger Agreement—Conditions to the Merger” and “The Transaction Agreements—The Separation Agreement—Conditions to the Distribution.”

Ecolab may waive any of the conditions to this Exchange Offer prior to the expiration of this Exchange Offer. ChampionX has no right to waive any of the conditions to this Exchange Offer. Apergy has no right to waive any of the conditions to this Exchange Offer (however, Apergy does have the right to waive certain conditions relating to the Merger).

Proration; Tenders for Exchange by Holders of Fewer than 100 Shares of Ecolab Common Stock

If, upon the expiration of this Exchange Offer, Ecolab stockholders have validly tendered more shares of Ecolab common stock than Ecolab is able to accept for exchange (taking into account the exchange ratio and the total number of shares of ChampionX common stock being exchanged by Ecolab in this Exchange Offer), Ecolab will accept for exchange the shares of Ecolab common stock validly tendered and not properly withdrawn by each tendering stockholder on a pro rata basis, based on the proportion that the total number of shares of Ecolab common stock to be accepted for exchange bears to the total number of shares of Ecolab common stock validly tendered and not properly withdrawn (rounded to the nearest whole number of shares of Ecolab common stock, and subject to any adjustment necessary to ensure the exchange of all shares of ChampionX common stock owned by Ecolab), except for tenders of odd lots, as described below.

Ecolab will announce the preliminary proration factor for this Exchange Offer at http://www.championxexchangeoffer.com and separately by press release promptly after the expiration of this Exchange Offer. Upon determining the number of shares of Ecolab common stock validly tendered for exchange and not properly withdrawn, Ecolab will announce the final results of this Exchange Offer, including the final proration factor for this Exchange Offer.

Beneficial holders (other than participants in any of the Ecolab Savings Plans) of less than 100 shares of Ecolab common stock who validly tender all of their shares may elect not to be subject to proration by completing the section in the applicable letter of transmittal entitled “Proration / Odd-Lot.” If your odd-lot shares are held by a broker for your account, you can contact the broker and request this preferential treatment. All of your odd-lot shares will be accepted for exchange without proration if Ecolab completes this Exchange Offer.

Fractional Shares

Fractional shares of ChampionX common stock will be issued in the Distribution. ChampionX common stock (including the fractional shares) will be held by the Exchange Offer agent for the benefit of Ecolab stockholders whose shares of Ecolab common stock are accepted for exchange in this Exchange Offer and, if this Exchange Offer is completed but not fully subscribed, for distribution in the clean-up spin-off. If this Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), Ecolab intends to distribute all shares (including the fractional shares) of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab. In the Merger, no fractional shares of Apergy common stock will be delivered to holders of shares of ChampionX common stock. Instead, holders of shares of ChampionX common stock who would otherwise be entitled to receive a fractional share of Apergy common stock will receive in cash the dollar amount (rounded to the nearest whole cent) determined by multiplying such fraction by the closing price of Apergy common stock on the NYSE on the last business day prior to the effective time of the Merger. The amount received by such holders of shares of ChampionX common stock will be net of any required withholding taxes.

Holders who are tendering shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to their Ecolab Savings Plans and Ecolab Stock Purchase Plan accounts should refer to the

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special instructions provided to them by or on behalf of their applicable plan administrator for information that is specific to the Ecolab Savings Plans and the Ecolab Stock Purchase Plan.

Procedures for Tendering

For you to validly tender your shares of Ecolab common stock pursuant to this Exchange Offer, prior to the expiration of this Exchange Offer:

Delivery of ChampionX Common Stock

Upon consummation of this Exchange Offer, Ecolab will deliver to the Exchange Offer agent a book-entry authorization representing (a) all of the shares of ChampionX common stock being exchanged in this Exchange Offer, with instructions to hold the shares of ChampionX common stock as agent for the holders of shares of Ecolab common stock validly tendered and not properly withdrawn in this Exchange Offer whose shares are accepted in this Exchange Offer and (b) in the case of a clean-up spin-off, if any, Ecolab stockholders whose shares of Ecolab common stock remain outstanding after the consummation of this Exchange Offer. Shares of Apergy common stock will be delivered following the effectiveness of the Merger, pursuant to the procedures determined by the Exchange Offer agent. See “Exchange Offer—Terms of This Exchange Offer—Exchange of Shares of Ecolab Common Stock.”

Withdrawal Rights

Shares of Ecolab common stock validly tendered pursuant to this Exchange Offer may be withdrawn at any time before 12:01 a.m., New York City time, on the expiration date by following the procedures described herein. If you change your mind again, you may re-tender your Ecolab common stock by again following the procedures for this Exchange Offer prior to the expiration of this Exchange Offer.

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If you hold shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) through the Ecolab Savings Plans or the Ecolab Stock Purchase Plan, you will be provided with special instructions by or on behalf of your plan administrator on how to withdraw your shares (or units in respect of shares) and you must deliver any required information in a timely manner in order for the tabulator for the Ecolab Savings Plans and the agent for the Ecolab Stock Purchase Plan to withdraw your election to exchange from the final tabulation. The deadline will be specified in the special instructions provided to you (or, if this Exchange Offer is extended, any new withdrawal deadline established by the plan administrator).

No Appraisal Rights

No appraisal rights are available to holders of Ecolab common stock in connection with this Exchange Offer or any clean-up spin-off (in the event this Exchange Offer is not fully subscribed) of shares of ChampionX common stock. If this Exchange Offer were to be terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), no appraisal rights would be available to holders of Ecolab common stock in the spin-off of shares of ChampionX common stock.

Distribution of ChampionX Common Stock Remaining After This Exchange Offer

In the event this Exchange Offer is not fully subscribed, all shares of ChampionX common stock owned by Ecolab that are not exchanged in this Exchange Offer will be distributed in the clean-up spin-off to holders of Ecolab common stock whose shares of Ecolab common stock remain outstanding after the consummation of this Exchange Offer. The record date for the clean-up spin-off, if any, will be announced by Ecolab. Any Ecolab stockholder who validly tenders (and does not properly withdraw) shares of Ecolab common stock that are accepted in this Exchange Offer will with respect to such shares waive their rights to receive, and forfeit any rights to, shares of ChampionX common stock distributed in the clean-up spin-off.

If this Exchange Offer is consummated, the Exchange Offer agent will calculate the exact number of shares of ChampionX common stock not exchanged in this Exchange Offer to be distributed in the clean-up spin-off, and that number of shares of ChampionX common stock will be held as agent for holders of Ecolab common stock entitled thereto.

If this Exchange Offer is terminated by Ecolab without the exchange of shares, but the conditions to consummation of the Transactions have otherwise been satisfied, Ecolab intends to distribute all shares of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab.

Legal Limitations; Certain Matters Relating to Non-U.S. Jurisdictions

This prospectus is not an offer to buy, sell or exchange and it is not a solicitation of an offer to buy, sell or exchange any shares of ChampionX common stock, shares of Ecolab common stock or shares of Apergy common stock in any jurisdiction in which the offer, sale or exchange is not permitted. After the consummation of this Exchange Offer and prior to the Merger, it will not be possible to trade the ChampionX common stock. Countries outside the United States generally have their own legal requirements that govern securities offerings made to persons resident in those countries and often impose stringent requirements about the form and content of offers made to the general public. None of Ecolab, Apergy or ChampionX has taken any action under non-U.S. regulations to facilitate a public offer to exchange the shares of Ecolab common stock, Apergy common stock or ChampionX common stock outside the United States. Accordingly, the ability of any non-U.S. person to tender shares of Ecolab common stock in this Exchange Offer will depend on whether there is an exemption available under the laws of such person’s home country that would permit the person to participate in this Exchange Offer without the need for Ecolab, Apergy or ChampionX to take any action to facilitate a public offering in that country or otherwise. For example, some countries exempt transactions from the rules governing public offerings if they involve persons who meet certain eligibility requirements relating to their status as sophisticated or professional investors.

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Non-U.S. stockholders should consult their advisors in considering whether they may participate in this Exchange Offer in accordance with the laws of their home countries and, if they participate, whether there are any restrictions or limitations on transactions in the shares of Ecolab common stock, Apergy common stock or ChampionX common stock that may apply in their home countries. None of Ecolab, Apergy or ChampionX can provide any assurance about whether such limitations may exist. See “Exchange Offer—Certain Matters Relating to Non-U.S. Jurisdictions” for additional information about limitations on this Exchange Offer outside the United States.

Risk Factors

In deciding whether to tender your shares of Ecolab common stock in this Exchange Offer, you should carefully consider the matters described in the section entitled “Risk Factors,” as well as other information included in this prospectus and the other documents to which you have been referred.

Debt Financing (See “Additional Agreements Related to the Separation, the Distribution and the Merger—Apergy Credit Facility and—ChampionX Credit Facility” beginning on page 217)

In connection with the Transactions, ChampionX will enter into a credit agreement with respect to a $537 million senior secured term loan credit facility to finance the Cash Payment to Ecolab and otherwise pay certain expenses in connection with the Transactions. Also, in connection with the Transactions, Apergy has entered into an amendment to its existing credit agreement to, among other things, increase its revolving commitments thereunder by a principal amount up to $150 million.

Board of Directors and Management of Apergy After the Merger (See “The Transactions—Board of Directors and Executive Officers of Apergy Following the Merger; Operations Following the Merger” beginning on page 184)

After the Merger, the Apergy Board of Directors will consist of nine directors: the seven current directors on the Apergy Board of Directors and two directors designated by Ecolab. One of the Ecolab board designees shall be appointed as a Class I director of Apergy, and the second of the Ecolab board designees shall be appointed as a Class II director of Apergy. Each of the directors designated by Ecolab must qualify as an independent director, as such term is defined in NYSE Rule 303A.02.

Apergy’s current President and Chief Executive Officer, Sivasankaran Somasundaram, and current Senior Vice President and Chief Financial Officer, Jay A. Nutt, will continue in their roles. Deric Bryant, current Executive Vice President & President of Ecolab’s ChampionX Business, is expected to serve as Chief Operating Officer of the combined company. Certain members of the ChampionX management team are expected to join the Apergy management team as well.

Interests of Certain Persons in the Transactions (See “The Transactions—Interests of Certain Persons in the Transactions” beginning on page 185)

The directors and executive officers of Ecolab and ChampionX will receive no extra or special benefit that is not shared on a pro rata basis by all other ChampionX stockholders in connection with the Transactions, except as described herein. None of Ecolab’s or ChampionX’s directors will receive any severance or other additional compensation as a result of the Transactions. Certain of Ecolab’s and ChampionX’s executive officers have financial interests in the Transactions that may be different from, or in addition to, the interests of stockholders generally. As with all Ecolab stockholders, if a director or executive officer of Ecolab or ChampionX owns shares of Ecolab common stock, such person may participate in this Exchange Offer on the same terms as other Ecolab stockholders. As of April 24, 2020, Ecolab’s directors and executive officers beneficially owned approximately 1.30% of the outstanding shares of Ecolab common stock. All of ChampionX’s outstanding common stock is currently owned directly by Ecolab.

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Certain of Apergy’s executive officers have financial interests in the Transactions that may be different from, or in addition to, the interests of Apergy’s stockholders generally. The members of the Apergy Board of Directors were aware of and considered these interests, among other matters, in reaching the determination to approve the terms of the Transactions, including the Share Issuance and the Merger, and in recommending to Apergy’s stockholders that they vote to approve the Share Issuance. As of April 23, 2020, Apergy’s directors and executive officers beneficially owned approximately 0.66% of the outstanding shares of Apergy’s common stock.

Apergy’s Stockholders Meeting (See “The Transactions—Apergy’s Stockholders Meeting” on page 190)

Under the terms of the Merger Agreement, Apergy is required to call a meeting of its stockholders for the purpose of voting upon the issuance of shares of Apergy’s common stock in the Merger as promptly as reasonably practicable following the date on which the SEC has cleared Apergy’s proxy statement and, if required by the SEC as a condition to the mailing of Apergy’s proxy statement, the registration statement of Apergy has been declared effective. Apergy will ask its stockholders to vote on this matter at the special meeting of Apergy stockholders by delivering Apergy’s proxy statement to its stockholders in accordance with applicable law and its organizational documents. In accordance with NYSE Listing Rules, the DGCL, and Apergy’s organizational documents, the approval of the Share Issuance Proposal requires the affirmative vote of the holders of a majority of the voting power of Apergy present online or represented by proxy and entitled to vote on such matter, at a special meeting at which a quorum is present.

As of April 23, 2020, Apergy directors and executive officers and their affiliates were entitled to vote approximately 0.66% of the outstanding shares of Apergy common stock. Apergy currently expects that all Apergy directors and executive officers will vote their shares in favor of the Share Issuance Proposal, though none has entered into an agreement requiring them to do so.

As of April 28, 2020, ChampionX’s directors, executive officers and their affiliates were entitled to vote less than 0.01% of the outstanding shares of Apergy common stock. No vote of Ecolab stockholders is required in connection with the Transactions, and the only vote required with respect to ChampionX is by Ecolab as its sole stockholder, which stockholder approval has been obtained. No directors, executive officers or affiliates of ChampionX or Ecolab will have voting rights in connection with the Transactions with respect to their ownership of any Ecolab common stock or ChampionX common stock.

Accounting Treatment of the Merger (See “The Transactions—Accounting Treatment of the Merger” beginning on page 191)

Accounting Standards Codification Topic 805, Business Combinations, or ASC 805, requires the use of the acquisition method of accounting for business combinations. In applying the acquisition method, it is necessary to identify both the accounting acquiree and the accounting acquirer. In a business combination effected through an exchange of equity interests, such as the Merger, the entity that issues the interests (Apergy in this case) is generally the accounting acquirer; however, all pertinent facts and circumstances must be considered, including the following additional considerations:

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Apergy’s management has determined that Apergy represents the accounting acquirer in this combination based on an analysis of the criteria outlined in ASC 805 and the facts and circumstances specific to this transaction. As a result, Apergy will record the business combination in its financial statements and will apply the acquisition method to account for the acquired assets and assumed liabilities of the ChampionX Business upon consummation of the Merger. Applying the acquisition method includes recording the identifiable assets acquired and liabilities assumed at their fair values, and recording goodwill for the excess of the purchase price over the aggregate fair value of the identifiable assets acquired and liabilities assumed.

U.S. Federal Income Tax Consequences of the Distribution and the Merger (See “U.S. Federal Income Tax Consequences of the Distribution and the Merger” beginning on page 247)

Ecolab stockholders are generally not expected to recognize any gain or loss as a result of the Distribution or the Merger, except for any gain or loss attributable to the receipt of cash in lieu of a fractional share of Apergy common stock pursuant to the Merger. Ecolab is generally not expected to recognize any gain or loss as a result of the Distribution or the Merger.

Regulatory Approvals (See “The Transactions—Regulatory Approvals” beginning on page 191)

Under the HSR Act and related rules, the Merger may not be completed until the parties have filed notification and report forms with the Antitrust Division of the U.S. Department of Justice and the United States Federal Trade Commission, and observed a specified statutory waiting period. Apergy and Ecolab filed the requisite notification and report forms on January 3, 2020 and the parties were granted early termination of the waiting period under the HSR Act on January 13, 2020.

Additionally, Apergy and Ecolab have agreed to seek regulatory approvals in Canada, Azerbaijan, Nigeria, Kazakhstan, Saudi Arabia, Mexico and Russia. The approvals in the jurisdictions that are conditions to closing this Exchange Offer have been obtained.

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SUMMARY HISTORICAL AND PRO FORMA FINANCIAL INFORMATION

The following summary combined financial information of ChampionX and summary consolidated financial information of Ecolab and Apergy are being provided to help you in your analysis of the financial aspects of the Transactions. You should read this information in conjunction with the financial information included elsewhere and incorporated by reference into this prospectus. See “Where You Can Find Additional Information; Incorporation by Reference,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of ChampionX,” “Information About the ChampionX Business,” “Information About Ecolab,” “Information About Apergy,” “Selected Historical Combined Financial Information of ChampionX,” “Selected Historical Consolidated Financial Information of Ecolab” and “Selected Historical Condensed Consolidated Financial Information of Apergy.”

Summary Historical Combined Financial Information of ChampionX

The summary historical combined financial information presented in the table below consists of historical combined financial information of ChampionX as of the dates and for the periods presented. The summary historical combined financial information as of December 31, 2019 and 2018 and for the years ended December 31, 2019, 2018 and 2017 have been derived from ChampionX’s audited combined financial statements included elsewhere in this prospectus. The summary historical combined financial information as of December 31, 2017 has been derived from ChampionX’s audited combined financial statements that are not included or incorporated by reference in this prospectus.

The summary historical combined financial information includes costs of ChampionX’s business, which include the allocation of certain corporate expenses from Ecolab. ChampionX believes these allocations were made on a reasonable basis. The summary historical combined financial information may not be indicative of ChampionX’s future performance. The summary historical combined financial information should be read in conjunction with “Selected Historical Combined Financial Information of ChampionX,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of ChampionX” and the ChampionX audited historical combined financial statements and accompanying notes included elsewhere in this prospectus.

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Summary Historical Consolidated Financial Information of Ecolab

The following table presents the summary historical consolidated financial information of Ecolab. The summary historical consolidated financial information of Ecolab for the years ended December 31, 2019, 2018 and 2017, and as of December 31, 2019 and 2018 have been derived from Ecolab’s audited consolidated financial statements and related notes contained in the Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference in this prospectus. The summary historical consolidated financial information as of December 31, 2017 has been derived from Ecolab’s audited consolidated financial statements that are not included and not incorporated by reference in this prospectus. The summary historical consolidated financial information presented below should be read in conjunction with the audited financial statements and the accompanying notes and the “Management’s Discussion and Analysis of Financial Condition and Results of Operations” section contained in Ecolab’s annual report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference into this prospectus. For more information, see the section entitled “Where You Can Find Additional Information; Incorporation by Reference.”

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Summary Historical Consolidated Financial Information of Apergy

The summary historical consolidated financial information of Apergy for the years ended December 31, 2019, 2018 and 2017, and as of December 31, 2019 and 2018 have been derived from Apergy’s audited consolidated financial statements and related notes contained in the Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference in this prospectus. The summary historical consolidated financial information as of December 31, 2017 has been derived from Apergy’s audited consolidated financial statements that are not included or incorporated by reference in this prospectus. The information set forth below is only a summary and is not necessarily indicative of the results of future operations of Apergy or the combined company, and you should read the following information together with Apergy’s audited consolidated financial statements, the related notes and the section entitled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in Apergy’s Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference in this prospectus. For more information, see “Where You Can Find Additional Information; Incorporation by Reference” beginning on page 257 of this prospectus.

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Summary Unaudited Pro Forma Condensed Consolidated Financial Information of Ecolab

The summary unaudited pro forma condensed consolidated financial information of Ecolab has been prepared to reflect the Transactions as described in “Unaudited Pro Forma Condensed Consolidated Financial Statements of Ecolab.” The summary unaudited pro forma condensed consolidated financial information as of December 31, 2019 has been prepared to reflect the Transactions as if they had occurred on December 31, 2019. The summary unaudited pro forma condensed consolidated financial information for the year ended December 31, 2019 has been prepared to reflect the Transactions as if they had occurred on January 1, 2019.

The summary unaudited pro forma condensed consolidated financial information of Ecolab should be read in conjunction with “Selected Historical Combined Financial Information of ChampionX,” “Selected Historical Consolidated Financial Information of Ecolab,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of ChampionX,” “Unaudited Pro Forma Condensed Consolidated Financial Statements of Ecolab,” the ChampionX historical audited combined financial statements and accompanying notes, and the Ecolab historical audited consolidated financial statements, accompanying notes, and management’s discussion and analysis of financial condition and results of operations, included elsewhere in or incorporated by reference in this prospectus. The summary unaudited pro forma condensed consolidated financial information of Ecolab does not purport to represent what the actual results of operations or the financial position of Ecolab would have been had the Transactions occurred on the dates assumed, nor is it indicative of the future results of operations or financial position of Ecolab.

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Summary Unaudited Pro Forma Combined Financial Information of Apergy

The summary unaudited pro forma combined financial information of Apergy has been prepared by Apergy to reflect the Transactions described in the “Unaudited Pro Forma Condensed Combined Financial Statements of Apergy.” The summary unaudited pro forma combined balance sheet as of December 31, 2019 has been prepared to reflect the Transactions as if they had occurred on December 31, 2019. The summary unaudited pro forma combined statement of income for the year ended December 31, 2019 has been prepared to reflect the Transactions as if they had occurred on January 1, 2019.

The summary historical combined financial information includes costs of ChampionX’s business, which include the allocation of certain corporate expenses from Ecolab. ChampionX believes these allocations were made on a reasonable basis. The summary unaudited pro forma combined financial information of Apergy should be read in conjunction with “Selected Historical Combined Financial Information of ChampionX,” “Selected Historical Consolidated Financial Information of Apergy,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations of ChampionX,” “Unaudited Pro Forma Condensed Combined Financial Statements of Apergy,” the ChampionX historical combined financial statements and accompanying notes and the Apergy historical consolidated financial statements, accompanying notes, and management’s discussion and analysis of financial condition and results of operations, included elsewhere in or incorporated by reference in this prospectus. The summary unaudited pro forma combined financial information does not purport to represent what the actual results of operations or the financial position of the combined company would have been had the Transactions occurred on the dates assumed, nor are they indicative of future results of operations or financial position of the combined company.

Summary Historical and Pro Forma Per Share Information

The following tables set forth certain historical and pro forma per share information for Ecolab and Apergy. The Ecolab historical information has been derived from and should be read together with Ecolab’s audited

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consolidated financial statements and accompanying notes contained in Ecolab’s Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference into this prospectus. The Apergy historical information has been derived from and should be read together with Apergy’s audited consolidated financial statements and accompanying notes contained in Apergy’s Annual Report on Form 10-K for the year ended December 31, 2019, which is incorporated by reference into this prospectus. Ecolab’s pro forma information has been derived from the “Unaudited Pro Forma Condensed Consolidated Financial Statements of Ecolab” included elsewhere in this prospectus. Apergy’s pro forma information has been derived from the “Unaudited Pro Forma Condensed Combined Financial Statements of Apergy” included elsewhere in this prospectus.

Ecolab, Apergy and ChampionX may have performed differently had the Transactions occurred prior to the period or as of the date presented. The pro forma per share information does not purport to represent what the actual results of operations or the financial position would have been had the Transactions occurred on the dates assumed, nor is it indicative of the future results of operations or financial position of Ecolab, Apergy and ChampionX following the Transactions.

Ecolab

Apergy

ChampionX equivalent pro forma per share information under varying exchange rate assumptions

The unaudited pro forma per share information assumes that the Transactions are effected through a fully subscribed exchange offer with approximately 5.1 million shares of Ecolab common stock tendered and exchanged for approximately 122.0 million shares of ChampionX common stock, reflecting an assumed exchange ratio of 23.9627 shares of ChampionX common stock for each share of Ecolab common stock

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exchanged. Such exchange ratio has been determined by applying an indicative assumed discount of 10% and dividing the closing price of Ecolab’s common stock of $180.08 per share as of April 24, 2020 by 90% of the closing price of Apergy common stock of $8.35 per share as of April 24, 2020. Note the actual exchange ratio of Ecolab common stock to ChampionX common stock will be based on a calculated VWAP upon the terms and conditions disclosed elsewhere in this prospectus. The range of equivalent pro forma per share information as of and for the year ended December 31, 2019 shown below is calculated by multiplying the Apergy pro forma per share amounts by the exchange ratio based on varying exchange outcomes of ChampionX common stock for each share of Ecolab common stock tendered in this Exchange Offer.

Comparison of Market Prices

The following table sets forth the closing sale price per share of Ecolab common stock and Apergy common stock as reported on the NYSE as of December 18, 2019, the last trading day prior to the public announcement of the Transactions. Market price data for ChampionX common stock has not been presented because ChampionX is a wholly owned subsidiary of Ecolab, and shares of ChampionX common stock do not trade separately from shares of Ecolab common stock.

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RISK FACTORS

You should carefully consider the following risk factors, together with the other information contained or incorporated by reference in this prospectus, including the factors discussed in Part I, Item 1A—Risk Factors, in Apergy’s Annual Report on Form 10-K for the year ended December 31, 2019. The risks described below are not the only risks relating to the Separation, the Distribution, the Merger and this Exchange Offer or that Apergy currently faces or the combined company will face after the consummation of the Transactions. Additional risks and uncertainties not currently known or that are currently expected to be immaterial may also materially and adversely affect Apergy’s or the combined company’s business, financial condition or results of operations or the price of Apergy common stock following the consummation of the Transactions.

If any of the following risks and uncertainties develops into actual events, these events could have a material adverse effect on Apergy’s or the combined company’s business, financial condition or results of operations after the Transactions. In addition, past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods.

Risks Related to the Transactions

Apergy may not realize the anticipated cost synergies and growth opportunities from the Transactions.

Apergy expects that it will realize cost synergies, growth opportunities and other financial and operating benefits as a result of the Transactions. Apergy’s success in realizing these benefits, and the timing of their realization, depends on the successful integration of the business operations of the ChampionX Business with Apergy. Even if Apergy is able to integrate the ChampionX Business successfully, Apergy cannot predict with certainty if or when these cost synergies, growth opportunities and benefits will occur, or the extent to which they will actually be achieved. For example, the benefits from the Transactions may be offset by costs incurred in integrating the companies or in otherwise consummating the Transactions. Realization of any benefits and synergies could be affected by the factors described in other risk factors and a number of factors beyond Apergy’s control, including, without limitation, general economic conditions, further consolidation in the industry in which Apergy operates, increased operating costs and regulatory developments.

The integration of the ChampionX Business with Apergy following the Transactions may present significant challenges.

There is a significant degree of difficulty inherent in the process of integrating the ChampionX Business with Apergy. These difficulties include:

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The process of integrating operations could cause an interruption of, or loss of momentum in, the activities of the ChampionX Business or Apergy’s business. Members of Apergy’s or the ChampionX Business’ senior management may be required to devote considerable amounts of time to this integration process, which will decrease the time they will have to manage Apergy or the ChampionX Business, serve the existing Apergy business or the ChampionX Business, or develop new products or strategies. If Apergy’s or the ChampionX Business’ senior management is not able to effectively manage the integration process, or if any significant business activities are interrupted as a result of the integration process, the business of Apergy or the ChampionX Business could suffer.

Apergy’s successful or cost-effective integration of the ChampionX Business cannot be assured. The failure to do so could have a material adverse effect on Apergy’s business, financial condition or results of operations after the Transactions.

Apergy and Ecolab may fail to obtain the required regulatory approvals in connection with the Merger in a timely fashion, if at all, or regulators may impose burdensome conditions.

Apergy and Ecolab are subject to certain antitrust and competition laws, and the proposed Merger is subject to review and approval by regulators under those laws. Although Apergy and Ecolab have agreed to use reasonable best efforts to obtain the requisite approvals, there can be no assurance that these regulatory approvals will be obtained. Failure to obtain these regulatory approvals could adversely affect Apergy’s ability to operate its business after the Transactions or jeopardize the consummation of the Transactions themselves.

For example, the requirement to receive certain regulatory approvals before the consummation of the Transactions could delay the completion of the Transactions if, for example, one or more government agencies request additional information from the parties in order to facilitate their review of the Transactions. Any delay in the completion of the Transactions could diminish the anticipated benefits of the Transactions or result in additional transaction costs, loss of revenue or other effects associated with uncertainty about the Transactions. In addition, these governmental entities may attempt to condition their approval of the Transactions on the imposition of conditions, terms, obligations or restrictions that could have a material adverse effect on the Transactions themselves or Apergy’s business after the Transactions, including, but not limited to, Apergy’s operating results or the value of its common stock. If Apergy agrees to any material conditions, terms, obligations or restrictions in order to obtain any approvals required to complete the Transactions, the business, financial condition or results of operations of the combined company may be adversely affected.

Failure to complete the Transactions could adversely impact the market price of Apergy common stock as well as its business and operating results.

The consummation of the Transactions is subject to numerous conditions, including without limitation: (i) the Distribution having taken place in accordance with the Separation Agreement; (ii) the effectiveness of Apergy’s registration statement registering Apergy common stock to be issued pursuant to the Merger Agreement, and any other registration statement required in connection with the Transactions; (iii) approval of the Share Issuance by the requisite vote of Apergy’s stockholders; (iv) obtaining antitrust or competition law regulatory approvals in certain jurisdictions; and (v) receipt by Ecolab of each of the Distribution Tax Opinion, the Merger Tax Opinion and the KPMG Tax Opinion with respect to certain aspects of the Transactions. See “The Transaction Agreements—The Merger Agreement—Conditions to the Merger.” There is no assurance that these conditions will be met and that the Transactions will be consummated.

If the Transactions are not completed for any reason, the price of Apergy common stock may decline to the extent that the market price of Apergy common stock reflects positive market assumptions that the Transactions will be completed and the related benefits will be realized. Apergy and Ecolab have expended and will continue to expend significant management time and resources and have incurred and will continue to incur significant expenses due to legal, advisory, printing and financial services fees related to the Transactions. These expenses

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must be paid regardless of whether the Transactions are consummated. Even if the Transactions are completed, any delay in the completion of the Transactions could diminish the anticipated benefits of the Transactions or result in additional transaction expenses, loss of revenue or other effects associated with uncertainty about the Transactions. If the Transactions are not consummated because the Merger Agreement is terminated, Apergy may be required under certain circumstances to pay Ecolab a termination fee of $89.8 million or may under other circumstances be required to reimburse Ecolab for expenses in connection with the Transactions in an amount equal to $25 million.

The pendency of the Merger could have an adverse effect on Apergy’s stock price, business, financial condition, results of operations or business prospects.

The announcement and pendency of the Merger could disrupt Apergy’s business in negative ways. For example, customers and other third-party business partners of Apergy or the ChampionX Business may seek to terminate and/or renegotiate their relationships with Apergy or ChampionX as a result of the Merger, whether pursuant to the terms of their existing agreements with Apergy and/or ChampionX or otherwise. In addition, current and prospective employees of Apergy and the ChampionX Business may experience uncertainty regarding their future roles with the combined company, which might adversely affect Apergy’s ability to retain, recruit and motivate key personnel. Should they occur, any of these events could adversely affect the stock price of, or harm the financial condition, results of operations or business prospects of, Apergy.

Apergy will incur significant costs related to the Transactions that could have a material adverse effect on its liquidity, cash flows and operating results.

Apergy expects to incur significant one-time costs in connection with the Transactions. These costs have been, and will continue to be, substantial and, in many cases, will be borne by Apergy whether or not the Merger is completed. A substantial majority of these one-time costs will be transaction-related fees and expenses and include, among others, fees paid to financial, legal, accounting and other professional fees and transition and pre-Merger integration planning-related expenses. While Apergy expects to be able to fund these one-time costs using cash from operations and borrowings under existing and anticipated credit sources, these costs will negatively impact Apergy’s liquidity, cash flows and results of operations in the periods in which they are incurred.

The Transactions may discourage other companies from trying to acquire Apergy before or for a period of time following completion of the Transactions.

Certain provisions in the Merger Agreement prohibit Apergy from soliciting any acquisition proposal during the pendency of the Merger. In addition, the Merger Agreement obligates Apergy to pay Ecolab a termination fee in certain circumstances. Apergy’s financial condition will be adversely affected as a result of the payment of the termination fee in certain circumstances involving alternative acquisition proposals, which might deter third parties from proposing alternative acquisition proposals, including acquisition proposals that might result in greater value to Apergy stockholders than the Transactions. In addition, certain provisions of the Tax Matters Agreement, which are intended to preserve the intended tax treatment of certain aspects of the Separation and the Distribution for U.S. federal income tax purposes, may discourage acquisition proposals for a period of time following the Transactions. Apergy currently expects to issue approximately 127.6 million shares of its common stock in connection with the Merger. See “The Transaction Agreements—The Merger Agreement—Merger Consideration.” Because Apergy will be a significantly larger company and have significantly more shares of common stock outstanding after the consummation of the Transactions, an acquisition of Apergy may become more expensive. As a result, some companies may not seek to acquire Apergy.

The Distribution could result in significant tax liability, and Apergy may be obligated to indemnify Ecolab for any such tax liability imposed on Ecolab.

The consummation of the Distribution is conditioned on Ecolab’s receipt of the Distribution Tax Opinion, which will provide that (among other things) the Contribution and Distribution, taken together, will qualify as a

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transaction described in Sections 355 and 368(a)(1)(D) of the Code, and an opinion from KPMG LLP, which we refer to as KPMG, that will address the tax treatment of certain aspects of the Transactions, which opinion we refer to as the KPMG Tax Opinion. If the Contribution and Distribution, taken together, so qualify, then (i) Ecolab stockholders will generally not recognize any gain or loss for U.S. federal income tax purposes as a result of the Distribution, and (ii) except for taxable income or gain possibly arising as a result of certain internal restructuring transactions undertaken in the Separation and with respect to any “intercompany transaction” required to be taken into account by Ecolab under the Treasury Regulations related to consolidated federal income tax returns, Ecolab will not recognize any gain or loss. None of Ecolab, ChampionX or Apergy intends to request any ruling from the Internal Revenue Service, which we refer to as the IRS, as to the U.S. federal income tax consequences of the Transactions. Neither the Distribution Tax Opinion nor the KPMG Tax Opinion will be binding on the IRS (or any applicable foreign taxing authorities) or the courts, and the IRS (or any applicable foreign taxing authorities) or the courts may not agree with the conclusions reached therein. There can be no assurance that the IRS (or any applicable foreign taxing authorities) will not successfully assert that the Distribution, or certain internal restructuring transactions undertaken in the Separation, are taxable transactions, and that a court will not sustain such assertion, which could result in tax being incurred by Ecolab stockholders and/or Ecolab.

If the Contribution and Distribution, taken together, were determined not to qualify as a transaction described in Sections 355 and 368(a)(1)(D) of the Code, for U.S. federal income tax purposes each Ecolab stockholder who receives ChampionX common stock in this Exchange Offer would generally be treated as recognizing taxable gain or loss equal to the difference between the fair market value of the ChampionX common stock received by the stockholder in this Exchange Offer and its tax basis in the shares of Ecolab common stock exchanged therefor, or, in certain circumstances, as receiving a taxable distribution equal to the fair market value of the ChampionX common stock received by the stockholder in this Exchange Offer. Further, if this Exchange Offer were not fully subscribed in such a situation and Ecolab undertook the clean-up spin-off, each Ecolab stockholder who receives ChampionX common stock in the clean-up spin-off would generally be treated as receiving a taxable distribution equal to the fair market value of the ChampionX common stock received by the stockholder in the clean-up spin-off.

In addition, if the Contribution and Distribution, taken together, were determined not to qualify as a transaction described in Sections 355 and 368(a)(1)(D) of the Code, for U.S. federal income tax purposes, Ecolab would generally recognize gain with respect to the transfer of ChampionX common stock in the Distribution if the value of ChampionX stock transferred exceeds Ecolab’s tax basis in such ChampionX stock.

Even if the Contribution and Distribution, taken together, otherwise qualify as a transaction described in Sections 355 and 368(a)(1)(D) of the Code, the Distribution will nonetheless be taxable to Ecolab (but not to Ecolab stockholders) pursuant to Section 355(e) of the Code if one or more persons acquire a 50% or greater interest (measured by vote or value) in the stock of Ecolab or ChampionX, directly or indirectly (including through acquisitions of the stock of Apergy after the Merger), as part of a plan or series of related transactions that includes the Distribution. For purposes of this test, the Merger will be treated as part of a plan that includes the Distribution, but it is expected that the Merger, standing alone, will not cause the Distribution to be taxable to Ecolab under Section 355(e) of the Code because holders of ChampionX common stock will own more than 50% of the common stock of Apergy following the Merger. However, if the IRS were to determine that other acquisitions of Ecolab stock, either before or after the Distribution, or Apergy stock after the Merger, are part of a plan or series of related transactions that includes the Distribution, such determination could result in the recognition of gain by Ecolab (but not by Ecolab stockholders) for U.S. federal income tax purposes, and the amount of taxes on such gain could be substantial. See “U.S. Federal Income Tax Consequences of the Distribution and the Merger.”

Under the Tax Matters Agreement, ChampionX and Apergy may be obligated, in certain cases, to indemnify Ecolab against taxes and certain tax-related losses of the Transactions that arise as a result of ChampionX’s or Apergy’s actions, or failure to act. See “U.S. Federal Income Tax Consequences of the Distribution and the

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Merger—Treatment of the Distribution” and “Additional Agreements Related to the Separation, the Distribution and the Merger—Tax Matters Agreement.” Any such indemnification obligation would likely be substantial and would likely have a material adverse effect on Apergy.

The Merger could result in significant tax liability to Dover, and Apergy may be obligated to indemnify Dover for any such tax liability imposed on Dover.

Under the tax matters agreement, dated May 9, 2018, which we refer to as the Dover Tax Matters Agreement, by and between Dover Corporation, which we refer to as Dover, and Apergy, Apergy would potentially be required to indemnify Dover against taxes incurred by Dover that arise as a result of Apergy taking or failing to take, as the case may be, certain actions that result in the distribution of Apergy by Dover, which we refer to as the Apergy Distribution, failing to meet the requirements of a tax-free distribution under Section 355 of the Code. The Dover Tax Matters Agreement required that, prior to entering into the Merger Agreement, Apergy obtain a tax opinion, acceptable to Dover, that the Merger would not cause the Apergy Distribution to fail to meet the requirements of a tax-free distribution under Section 355 of the Code and for Dover to consent to Apergy entering into and consummating the Merger. On December 18, 2019, Apergy obtained a tax opinion acceptable to Dover from Apergy’s tax counsel, Weil, Gotshal & Manges LLP, and Dover provided Apergy with Dover’s consent to entering into and consummating the Merger and all actions related thereto. Notwithstanding Apergy’s receipt of the tax opinion of Weil, Gotshal & Manges LLP, or Dover’s consent, Apergy must continue to indemnify Dover against certain tax-related losses under the Dover Tax Matters Agreement. The tax opinion of Weil, Gotshal & Manges LLP is not binding on the IRS or the courts, and the IRS or the courts may not agree with the conclusions reached therein. There can be no assurance that the IRS will not successfully assert that the Merger causes the Apergy Distribution to fail to meet requirements of a tax-free distribution under Section 355 of the Code and that a court will not sustain such assertion which could result in tax being incurred by Dover that must be indemnified by Apergy.

If the Merger is not treated as a reorganization within the meaning of Section 368(a) of the Code, the stockholders of ChampionX may have significant tax liability.

The consummation of the Merger is conditioned upon Ecolab’s receipt of the Merger Tax Opinion, which will provide that the Merger will be treated as a reorganization within the meaning of Section 368(a) of the Code. If the Merger is so treated, then Ecolab stockholders that receive ChampionX common stock in the Distribution will generally not recognize any gain or loss for U.S. federal income tax purposes as a result of the Merger, except for any gain or loss attributable to the receipt of cash in lieu of fractional shares of Apergy common stock. The opinion will be based on the assumptions, representations or statements made by Ecolab, ChampionX and Apergy, and if such assumptions, representations or statements are, or become, inaccurate, incorrect or incomplete, or if Ecolab, ChampionX or Apergy breach any of their covenants, the opinion may be invalid and the conclusions reached therein could be jeopardized. None of Ecolab, ChampionX or Apergy intends to request any ruling from the IRS as to the U.S. federal income tax consequences of the Merger. Ecolab’s receipt of the Merger Tax Opinion will not preclude the IRS from asserting that the Merger is taxable. In such event, U.S. Holders (as defined below) of ChampionX stock could be subject to U.S. federal income tax liability. See “U.S. Federal Income Tax Consequences of the Distribution and the Merger—Treatment of the Merger.”

Under the Tax Matters Agreement, Apergy and ChampionX will be restricted from taking certain actions that could adversely affect the intended tax treatment of the Transactions, and such restrictions could significantly impair Apergy’s and ChampionX’s ability to implement strategic initiatives that otherwise would be beneficial.

The Tax Matters Agreement generally restricts Apergy and ChampionX from taking certain actions after the Distribution that could adversely affect the intended tax treatment of the Transactions. Failure to adhere to these restrictions, could result in tax being imposed on Ecolab for which Apergy and ChampionX could bear responsibility and for which Apergy and ChampionX could be obligated to indemnify Ecolab. Any such indemnification obligation would likely be substantial and would likely have a material adverse effect on

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Apergy. In addition, even if Apergy and ChampionX are not responsible for tax liabilities of Ecolab under the Tax Matters Agreement, ChampionX nonetheless could be liable under applicable tax law for such liabilities if Ecolab were to fail to pay such taxes. Because of these provisions in the Tax Matters Agreement, Apergy and ChampionX will be restricted from taking certain actions, particularly for the two (or, in certain cases three) years following the Merger, including (among other things) the ability to freely issue stock, to make acquisitions and to raise additional equity capital. These restrictions could have a material adverse effect on Apergy’s liquidity and financial condition, and otherwise could impair Apergy’s and ChampionX’s ability to implement strategic initiatives. Also, ChampionX’s and Apergy’s indemnity obligation to Ecolab might discourage, delay or prevent a change of control that stockholders of Apergy may consider favorable.

Current Apergy stockholders’ percentage ownership interest in Apergy will be substantially diluted in the Merger.

Immediately following the Merger, the pre-Merger Apergy equityholders will own, in the aggregate, approximately 38% of the issued and outstanding Apergy common stock on a fully diluted basis. See “The Transaction Agreements—the Merger Agreement—Merger Consideration.” Consequently, Apergy’s pre-Merger equityholders, as a group, will be substantially diluted in the Merger and have less ability to exercise influence over the management and policies of Apergy following the Merger than immediately prior to the Merger.

The calculation of the number of shares of Apergy common stock to be distributed in the Merger will not be adjusted if there is a change in the value of the ChampionX Business or Apergy before the Merger is completed.

The number of shares of Apergy common stock to be issued by Apergy in the Merger will not be adjusted if there is a change in the value of the ChampionX Business or its assets or the value of Apergy prior to the closing of the Transactions. ChampionX stockholders will receive a fixed number of shares of Apergy common stock pursuant to the Merger rather than a number of shares with a particular fixed market value. As a result, the actual value of the Apergy common stock to be received by ChampionX stockholders in the Merger will depend on the value of such shares at the time of closing of the Merger, and may be more or less than the current value of Apergy common stock.

The number of shares of ChampionX common stock available in this Exchange Offer, and the corresponding percentage of the combined company that will be owned, in the aggregate, by pre-Merger ChampionX stockholders is subject to variation depending upon the number of shares of Apergy common stock underlying Apergy Options, Apergy Restricted Stock Units and Apergy Adjusted Performance Based Restricted Stock Units to be granted by Apergy to ChampionX employees pursuant to the Employee Matters Agreement.

Following the Transactions, ChampionX equityholders will own, in the aggregate, approximately 62% of the issued and outstanding Apergy common stock on a fully diluted basis. The proportion of this 62% that will be attributable to the shares to be owned by ChampionX stockholders (i.e., shares that will be available and distributed in this Exchange Offer or if necessary the clean-up spin-off) to the amount that will be attributable to the Apergy equity awards that will be issued to ChampionX employees will be determined by formulas set forth in the Merger Agreement and Employee Matters Agreement. See “The Transactions—The Merger—Calculation of the Merger Consideration” for a more detailed description of how the Merger consideration is calculated. Of the 127.6 million shares of Apergy common stock currently expected to be issued to ChampionX equityholders in connection with the Merger, based on recent share prices of Ecolab and Apergy common stock and the ChampionX employees’ equity awards outstanding, ChampionX currently expects that approximately 122.0 million shares of ChampionX common stock would be available in this Exchange Offer, but factors largely outside of Ecolab’s control, such as changes in Ecolab’s and/or Apergy’s stock price, could cause both the number of shares available in this Exchange Offer and the proportion of the approximately 62% combined company ownership for ChampionX equityholders that is attributable to the equity awards for ChampionX employees, to continue to fluctuate.

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The ChampionX Business may be negatively impacted if Apergy is unable to provide benefits and services, or access to equivalent financial strength and resources, to the ChampionX Business that historically have been provided by Ecolab.

The ChampionX Business has historically received benefits and services from Ecolab and has benefited from Ecolab’s financial strength and extensive network of service offerings. After the Transactions, ChampionX will be a subsidiary of Apergy, and the ChampionX Business will no longer benefit from Ecolab’s services, financial strength or business relationships to the extent not otherwise addressed in the other transaction documents contemplated by the Separation Agreement, referred to as the Transaction Documents. While Ecolab has agreed to provide certain transition services to ChampionX for a period of time following the consummation of the Transactions, it cannot be assured that Apergy will be able to adequately replace or provide resources formerly provided by Ecolab, or replace them at the same or lower cost. If Apergy is not able to replace the resources provided by Ecolab or is unable to replace them without incurring significant additional costs or is delayed in replacing the resources provided by Ecolab, Apergy’s results of operations may be negatively impacted.

The historical financial information of ChampionX may not be representative of its results if it had been operated independently of Ecolab and as a result, may not be a reliable indicator of future results of ChampionX.

The ChampionX Business is currently operated through various subsidiaries of Ecolab. Consequently, the financial information of ChampionX included in this prospectus has been derived from the consolidated financial statements and accounting records of Ecolab and reflects assumptions and allocations made by Ecolab. The financial position, results of operations and cash flows of ChampionX presented may be different from those that would have resulted if ChampionX had been operated as a standalone company or by a company other than Ecolab. For example, in preparing the financial statements of ChampionX, Ecolab made an allocation of Ecolab costs and expenses that are attributable to ChampionX. However, these costs and expenses reflect the costs and expenses attributable to ChampionX as part of a larger organization and do not necessarily reflect costs and expenses that would be incurred by ChampionX had it been operated independently, and may not reflect costs and expenses that would have been incurred had ChampionX been operated as a part of Apergy. As a result, the historical financial information of ChampionX may not be a reliable indicator of ChampionX’s future results or the results that it will achieve as a part of Apergy.

The unaudited pro forma condensed combined financial statements of Apergy are based in part on certain assumptions regarding the Transactions and may not be indicative of Apergy’s future operating performance.

The historical financial statements included or incorporated by reference in this prospectus consist of the separate financial statements of ChampionX and Apergy, respectively. The unaudited pro forma condensed combined financial statements presented in this prospectus are not necessarily indicative of what the financial position or the results of operations of the combined company would have been had the Merger occurred as of the date or for the periods presented. The pro forma amounts also do not indicate what the financial position or results of operations of the combined company will be in the future.

Apergy will account for the Merger as an acquisition of ChampionX, with Apergy being the accounting acquirer. Following the effective date of the Merger, Apergy expects to complete the purchase price allocation for the acquisition of ChampionX after determining the fair value of ChampionX’s assets and liabilities. The final purchase price allocation may be different than the preliminary one reflected in the unaudited pro forma purchase price allocation presented in this prospectus, and this difference may be material.

The unaudited pro forma combined financial information does not reflect the costs of any integration activities or transaction-related costs or incremental capital expenditures that Apergy management believes are necessary to realize the anticipated synergies from the Transactions. Accordingly, the unaudited pro forma combined financial information included in this prospectus does not reflect what the combined company’s results of operations or operating condition would have been had Apergy and ChampionX been a consolidated entity during all periods presented, or what the combined company’s results of operations and financial condition will be in the future.

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Apergy and the ChampionX Business may have difficulty attracting, motivating and retaining executives and other employees in light of the Transactions.

Uncertainty about the effect of the Transactions on current Apergy employees and/or ChampionX Employees may have an adverse effect on Apergy and the ChampionX Business. This uncertainty may impair Apergy’s and the ChampionX Business’ ability to attract, retain and motivate personnel until the Transactions are completed. Employee retention may be particularly challenging during the pendency of the Transactions, as employees may feel uncertain about their future roles with Apergy or the ChampionX Business after their combination. If large numbers of employees, or a concentration of critical employees of Apergy or the ChampionX Business depart because of issues relating to the uncertainty or perceived difficulties of integration or a desire not to become employees of Apergy after the Transactions, Apergy’s ability to realize the anticipated benefits of the Transactions could be reduced.

The Separation Agreement limits the combined company’s ability to engage in certain activities competitive with Ecolab.

The Separation Agreement includes non-compete provisions pursuant to which Apergy generally agreed to not compete in the Water and Downstream Field businesses of Ecolab for five years following the Distribution subject to certain exceptions set forth in the Separation Agreement. See “The Transaction Agreements—The Separation Agreement—Covenant Not to Compete.” The foregoing restrictions may limit the combined company’s ability to engage in certain activities, may potentially lead to disputes and may materially and adversely affect the business, financial condition and results of operations of the combined company.

The trading prices of Apergy common stock may not be an appropriate proxy for the prices of ChampionX common stock.

The calculated per-share value for ChampionX common stock is based on the trading prices for Apergy common stock, which may not be an appropriate proxy for the prices of ChampionX common stock. There is currently no trading market for ChampionX common stock. Ecolab believes, however, that the trading prices for Apergy common stock are an appropriate proxy for the trading prices of ChampionX common stock because immediately following the consummation of this Exchange Offer, Merger Sub will be merged with and into ChampionX, whereby ChampionX will continue as the surviving corporation and a wholly owned subsidiary of Apergy. In the Merger, each outstanding share of ChampionX common stock will be cancelled and retired and will cease to exist and the holders of shares of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will receive the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock equal to the Merger Exchange Ratio. In addition, ChampionX will authorize the issuance of a number of shares of ChampionX common stock such that the total number of shares of ChampionX common stock outstanding immediately prior to the Distribution will be that number that results in the Merger Exchange Ratio equaling one. As a result, each share of ChampionX common stock (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into one share of Apergy common stock in the Merger. There can be no assurance, however, that Apergy common stock after the issuance of shares of Champion common stock and the Merger will trade on the same basis as Apergy common stock trades prior to the Transactions. In addition, it is possible that the trading prices of Apergy common stock prior to consummation of the Merger will not fully reflect the anticipated value of Apergy common stock after the Merger. For example, trading prices of Apergy common stock on the Valuation Dates could reflect some uncertainty as to the timing or consummation of the Merger or could reflect trading activity by investors seeking to profit from market arbitrage.

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Risks Related to this Exchange Offer

Tendering Ecolab stockholders may receive a reduced premium or may not receive any premium in this Exchange Offer.

This Exchange Offer is designed to permit you to exchange your shares of Ecolab common stock for shares of ChampionX common stock at a 10% discount to the per-share value of ChampionX common stock, calculated as set forth in this prospectus. Stated another way, for each $100 of your Ecolab common stock accepted for exchange in this Exchange Offer, you will receive approximately $111.11 of ChampionX common stock (subject to the exception described below). The value of the Ecolab common stock will be based on the calculated per-share value of Ecolab common stock on the NYSE and the value of the shares of ChampionX common stock will be based on the calculated per-share value of Apergy common stock on the NYSE, in each case determined by reference to the simple arithmetic average of the daily VWAP on each of the Valuation Dates.

The number of shares you can receive is, however, subject to an upper limit of 24.6667 shares of ChampionX common stock for each share of Ecolab common stock accepted for exchange in this Exchange Offer. As a result, you may receive less than $111.11 of ChampionX common stock for each $100 of Ecolab common stock, depending on the calculated per-share value of Ecolab common stock and the calculated per-share value of ChampionX common stock at the expiration date. Because of the limit on the number of shares of ChampionX common stock you will receive in this Exchange Offer, if there is a drop of sufficient magnitude in the trading price of Apergy common stock relative to the trading price of Ecolab common stock, and/or if there is an increase of sufficient magnitude in the trading price of Ecolab common stock relative to the trading price of Apergy common stock, you may not receive $111.11 of ChampionX common stock for each $100 of Ecolab common stock, and could receive much less.

For example, if the calculated per-share value of Ecolab common stock was $210.31 (the highest closing price for Ecolab common stock on the NYSE during the three-month period ending on the second to last full trading day prior to commencement of this Exchange Offer) and the calculated per-share value of ChampionX common stock was $3.02 (the lowest closing price for Apergy common stock on the NYSE during that three-month period), the value of ChampionX common stock, based on the Apergy common stock price, received for shares of Ecolab common stock accepted for exchange would be approximately $35 for each $100 of Ecolab common stock accepted for exchange.

This Exchange Offer does not provide for a minimum exchange ratio. See “Exchange Offer—Terms of This Exchange Offer.” If the upper limit on the number of shares of ChampionX common stock that can be received for each share of Ecolab common stock tendered and accepted for exchange is in effect, then the exchange ratio will be fixed at the upper limit.

For example, if the trading price of Ecolab common stock were to increase during the last two full trading days of this Exchange Offer, the average Ecolab stock price used to calculate the exchange ratio would likely be lower than the closing price of shares of Ecolab common stock on the last full trading day prior to the expiration date of this Exchange Offer. As a result, you would receive fewer shares of ChampionX common stock, and therefore effectively fewer shares of Apergy common stock, for each $100 of shares of Ecolab common stock than you would have if the average Ecolab stock price were calculated on the basis of the closing price of shares of Ecolab common stock on the last full trading day prior to the expiration date of this Exchange Offer or on the basis of an averaging period that includes the last two full trading days prior to the expiration of this Exchange Offer. Similarly, if the trading price of Apergy common stock were to decrease during the last two full trading days prior to the expiration of this Exchange Offer, the average Apergy stock price used to calculate the exchange ratio would likely be higher than the closing price of Apergy common stock on the last full trading day prior to the expiration date. This could also result in your receiving fewer shares of ChampionX common stock, and therefore effectively fewer shares of Apergy common stock, for each $100 of Ecolab common stock than you would have received if the average Apergy common stock price were calculated on the basis of the closing price of Apergy common stock on the last full trading day prior to the expiration date or on the basis of an averaging period that included the last two full trading days prior to the expiration of this Exchange Offer.

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In addition, there is no assurance that holders of shares of Ecolab common stock that are exchanged for shares of ChampionX common stock in this Exchange Offer will be able to sell the shares of Apergy common stock after receipt in the Merger at prices comparable to the calculated per-share value of ChampionX common stock at the expiration date. For example, in the event that this Exchange Offer is not fully subscribed, Ecolab will distribute in the clean-up spin-off the remaining shares of ChampionX common stock that will convert into Apergy common stock in the Merger. Ecolab stockholders who receive Apergy common stock as a result of the clean-up spin-off (in the event this Exchange Offer is not fully subscribed) and the Merger may not want to be Apergy common stock holders and may sell those shares immediately in the public market. It is also possible that some Ecolab stockholders will sell the Apergy common stock they receive if, for reasons such as Apergy’s business profile or market capitalization, Apergy does not fit their investment objectives, or in the case of index funds, Apergy is not a participant in the index in which they are investing. The sales of significant amounts of Apergy common stock relating to the above events or the perception in the market that such sales will occur may decrease the market price of Apergy’s common stock.

Following the conversion of shares of ChampionX common stock into shares of Apergy common stock in the Merger, the former holders of shares of ChampionX common stock may experience a delay prior to receiving their shares of Apergy common stock or their cash in lieu of fractional shares, if any.

Following the conversion of shares of ChampionX common stock into shares of Apergy common stock, the former holders of shares of ChampionX common stock will receive their shares of Apergy common stock or cash in lieu of fractional shares, if any, only upon surrender of all necessary documents, duly executed, to the Exchange Offer agent. Until the distribution of the shares of Apergy common stock to the individual stockholder has been completed, the relevant holder of shares of Apergy common stock will not be able to sell its shares of Apergy common stock. Consequently, in case the market price for Apergy common stock should decrease during that period, the relevant stockholder would not be able to stop any losses by selling the shares of Apergy common stock. Similarly, the former holders of shares of ChampionX common stock who receive cash in lieu of fractional shares will not be able to invest the cash until the distribution to the relevant stockholder has been completed, and they will not receive interest payments for this time period.

Ecolab stockholders’ investment will be subject to different risks if this Exchange Offer is completed.

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Whether or not Ecolab stockholders tender their shares of Ecolab common stock, any Ecolab shares they hold after the completion of this Exchange Offer will reflect a different investment from the investment they previously held because Ecolab will no longer own the ChampionX Business.

Risks Related to the Combined Company’s Business Following the Transactions

Sales of Apergy common stock after the Transactions may negatively affect the market price of Apergy common stock.

The shares of Apergy common stock to be issued in the Transactions to holders of shares of ChampionX common stock will generally be eligible for immediate resale. The market price of Apergy common stock could decline as a result of sales of a large number of shares of Apergy common stock in the market after the consummation of the Transactions or even the perception that these sales could occur.

It is expected that upon completion of the Transactions, ChampionX equityholders will hold approximately 62% of Apergy’s common stock on a fully-diluted basis and Apergy equityholders will hold approximately 38% of Apergy’s common stock on a fully-diluted basis. Currently, Ecolab stockholders may include index funds that have performance tied to certain stock indices and institutional investors subject to various investing guidelines.

Because Apergy may not be eligible to be included in these indices following the consummation of the Transactions or may not meet the investing guidelines of some of these institutional investors and index funds, such investors and index funds may decide to or may be required to sell the shares of Apergy common stock that they receive in the Transactions. In addition, the investment fiduciaries of Ecolab’s defined contribution plans may decide to sell any shares of Apergy common stock that the trusts for these plans receive in the Transactions, or may decide not to participate in this Exchange Offer, in response to their fiduciary obligations under applicable law. These sales, or the possibility that these sales may occur, may also make it more difficult for Apergy to obtain additional capital by selling equity securities in the future at a time and at a price that it deems appropriate.

Trends in crude oil and natural gas prices may affect the drilling and production activity, profitability and financial stability of the combined company’s customers and therefore the demand for, and profitability of the combined company’s products and services, which could have a material adverse effect on the combined company’s business, results of operations and financial condition.

The oil and gas industry is cyclical in nature and experiences periodic downturns of varying length and severity. The oil and gas industry experienced a significant downturn in 2015 and 2016 as a result of a sharp decline in crude oil prices. Crude oil prices slightly recovered in late 2016 and into 2017, but experienced a volatile decline again during late 2018. Price volatility continued throughout 2019 and, partially due to the emergence of the COVID-19 pandemic and failure of the Organization of the Petroleum Exporting Countries (“OPEC”) and other major producers to agree on production cuts, has become more extreme in 2020. Demand for the combined company’s products and services is sensitive to the level of capital spending by oil and natural gas companies and the corresponding drilling and production activity. The level of drilling and production activity is directly affected by trends in crude oil and natural gas prices, which are influenced by numerous factors affecting the supply and demand for oil and gas, including:

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Many of these factors are beyond the combined company’s control. For example, in March 2020, members of OPEC and Russia considered extending their previously agreed oil production cuts and potentially making additional oil production cuts. However, these negotiations were unsuccessful. As a result, Saudi Arabia announced a significant reduction in its export prices and Russia announced the expiration of all agreed oil production cuts between members of OPEC and Russia. Following these announcements, and also as a result of the increased global scale and severity of the COVID-19 outbreak during this period, global oil and natural gas prices declined sharply. While a deal to cut production has since been announced by OPEC and its allies, the situation has resulted in a significant downturn in the industry and continued volatility in oil prices, even resulting in a negative oil futures price on one recent day. To the extent that the outbreak of COVID-19 continues to negatively impact demand and OPEC members and other oil exporting nations fail to implement production cuts or other actions that are sufficient to support and stabilize commodity prices, ChampionX and Apergy expect there to be an excess supply of oil and natural gas for a sustained period.

Apergy expects continued volatility in both crude oil and natural gas prices (including that such prices could remain at current levels or decline further for an extended period of time), as well as in the level of drilling and production related activities. The combined company’s ability to regulate its operating activities in response to lower oilfield service activity levels during periodic industry downturns will be important to its business, results of operations and prospects. However, a significant and/or extended continuation of the recent downturn in the industry could result in the reduction in demand for the combined company’s products and services and could have a material adverse effect on its business, results of operations, financial condition and cash flows.

The combined company might be unable to successfully compete with other companies in its industry.

The markets in which Apergy and the ChampionX Business operate, and the combined company will operate, are highly competitive. The principal competitive factors in Apergy’s and the ChampionX Business’s markets are, and the combined company’s markets will be, customer service, product quality and performance, price, breadth of product offering, market expertise and innovation. In some of Apergy’s and the ChampionX Business’s product and service offerings, Apergy and ChampionX compete with the oil and gas industry’s largest oilfield service providers. These large national and multi-national companies may have longer operating histories, greater brand recognition, and a stronger presence in geographic markets than us. They may also have more robust financial and technical capabilities. In addition, Apergy and the ChampionX Business compete, and the

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combined company will compete, with many smaller companies capable of effectively competing on a regional or local basis. The combined company’s competitors may be able to respond more quickly to new or emerging technologies and services and changes in customer requirements. Many contracts are awarded on a bid basis, which further increases competition based on price. As a result of the competitive environment in which it operates, the combined company may lose market share, be unable to maintain or increase prices for its products and services, or be unable to acquire additional business opportunities, which could have a material adverse effect on its business, results of operations, financial condition and cash flows.

If the combined company is unable to develop new products and technologies, its competitive position may be impaired, which could materially and adversely affect its sales and market share.

The markets in which Apergy and the ChampionX Business operate, and the combined company will operate, are characterized by changing technologies and the introduction of new products and services. As a result, the combined company’s success is dependent upon its ability to develop or acquire new products and services on a cost-effective basis, to introduce them into the marketplace in a timely manner, and to protect and maintain critical intellectual property assets related to these developments. Difficulties or delays in research, development or production of new products and technologies, or failure to gain market acceptance of new products and technologies, may significantly reduce future revenue and materially and adversely affect the combined company’s competitive position. While the combined company intends to continue to commit financial resources and effort to the development of new products and services, it may not be able to successfully differentiate its products and services from those of its competitors. The combined company’s customers may not consider its proposed products and services to be of value to them or may not view them as superior to its competitors’ products and services. In addition, the combined company’s competitors or customers may develop new technologies which address similar or improved solutions to the combined company’s existing technologies. Further, the combined company may not be able to adapt to evolving markets and technologies, develop new products, achieve and maintain technological advantages or protect technological advantages through intellectual property rights. If the combined company does not successfully compete through the development and introduction of new products and technologies, its business, results of operations, financial condition and cash flows could be materially adversely affected.

The combined company could lose customers or generate lower revenue, operating profits and cash flows if there are significant increases in the cost of raw materials or if it is unable to obtain raw materials.

Apergy purchases, and the combined company will purchase, raw materials, sub-assemblies and components for use in manufacturing operations, which exposes it to volatility in prices for certain commodities. Significant price increases for these commodities could adversely affect the combined company’s operating profits. While the combined company will generally attempt to mitigate the impact of increased raw material prices by endeavoring to make strategic purchasing decisions, broadening its supplier base and passing along increased costs to customers, there may be a time delay between the increased raw material prices and the ability to increase the prices of products. Additionally, the combined company may be unable to increase the prices of products due to a competitor’s pricing pressure or other factors. While raw materials are generally available now, the inability to obtain necessary raw materials could affect the combined company’s ability to meet customer commitments and satisfy market demand for certain products. Certain of Apergy’s and the ChampionX Business’s product lines depend on a limited number of third-party suppliers and vendors. The ability of these third parties to deliver raw materials may be affected by events beyond Apergy’s and the ChampionX Business’s control. In addition, public health threats, such as the coronavirus, severe influenza and other highly communicable viruses or diseases could limit access to vendors and their facilities, or the ability to transport raw materials from the combined company’s vendors, which would adversely affect the combined company’s ability to obtain necessary raw materials for certain of its products. Consequently, a significant price increase in raw materials, or their unavailability, may result in a loss of customers and adversely impact the combined company’s business, results of operations, financial condition and cash flows.

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Federal, state and local legislative and regulatory initiatives relating to oil and gas development and the potential for related litigation could result in increased costs and additional operating restrictions or delays for the combined company’s customers, which could reduce demand for the combined company’s products and negatively impact the combined company’s business, financial condition and results of operations.

Environmental laws and regulations could limit the combined company’s customers’ exploration and production activities. Although Apergy and the ChampionX Business do not directly engage in drilling or hydraulic fracturing activities, Apergy and the ChampionX Business provide products and services to operators in the oil and gas industry. There has been significant growth in opposition to oil and gas development both in the United States and globally. This opposition is focused on attempting to limit or stop hydrocarbon development in certain areas. Examples of such opposition include: (i) efforts to reduce access to public and private lands, (ii) delaying or canceling permits for drilling or pipeline construction, (iii) limiting or banning industry techniques such as hydraulic fracturing, and/or adding restrictions on the use of water and associated disposal, (iv) delaying or denying air-quality permits, and (v) advocating for increased regulations, punitive taxation, or citizen ballot initiatives or moratoriums on industry activity.

In addition, various state and local governments have implemented, or are considering, increased regulatory oversight of oil and gas development through additional permitting requirements, operational restrictions, including on the time, place and manner of drilling activities, disclosure requirements and temporary or permanent bans on hydraulic fracturing or other facets of crude oil and natural gas exploration and development in certain areas such as environmentally sensitive watersheds. Increased regulation and opposition to oil and gas activities could increase the potential for litigation concerning these activities, and could include companies who provide products and services used in hydrocarbon development, such as Apergy’s.

The adoption of new laws or regulations at the federal, state, or local levels imposing reporting obligations, or otherwise limiting or delaying hydrocarbon development, could make it more difficult to complete oil and gas wells, increase the combined company’s customers’ costs of compliance and doing business, and otherwise adversely affect the oil and gas activities they pursue. Such developments could negatively impact demand for the combined company’s products and services. In addition, heightened political, regulatory and public scrutiny, including lawsuits, could expose the combined company or the combined company’s customers to increased legal and regulatory proceedings, which could be time-consuming, costly, or result in substantial legal liability or significant reputational harm. The combined company could be directly affected by adverse litigation or indirectly affected if the cost of compliance or the risks of liability limit the ability or willingness of the combined company’s customers to operate. Such costs and scrutiny could directly or indirectly, through reduced demand for the combined company’s products and services, have a material adverse effect on the combined company’s business, results of operations, financial condition and cash flows.

The combined company and its customers will be subject to extensive environmental and health and safety laws and regulations that may increase the combined company’s costs, limit the demand for its products and services or restrict its operations.

The combined company’s operations and the operations of the combined company’s customers will be subject to numerous and complex federal, state, local and foreign laws and regulations relating to the protection of human health, safety and the environment. These laws and regulations may adversely affect the combined company’s customers by limiting or curtailing their exploration, drilling and production activities, the products and services it designs, markets and sells and the facilities where it manufactures its products. For example, the combined company’s operations and the operations of the combined company’s customers will be subject to numerous and complex laws and regulations that, among other things: may regulate the management and disposal of hazardous and non-hazardous wastes; may require acquisition of environmental permits related to its operations; may restrict the types, quantities and concentrations of various materials that can be released into the environment; may limit or prohibit operational activities in certain ecologically sensitive and other protected areas; may regulate specific health and safety criteria addressing worker protection; may require compliance with

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operational and equipment standards; may impose testing, reporting and record-keeping requirements; and may require remedial measures to mitigate pollution from former and ongoing operations. Sanctions for noncompliance with such laws and regulations may include revocation of permits, corrective action orders, administrative or civil penalties, criminal prosecution and the imposition of injunctions to prohibit certain activities or force future compliance.

Some environmental laws and regulations provide for joint and several strict liability for remediation of spills and releases of hazardous substances. In addition, the combined company or its customers may be subject to claims alleging personal injury or property damage as a result of alleged exposure to hazardous substances, as well as damage to natural resources. These laws and regulations may expose the combined company or its customers to liability for the conduct of or conditions caused by others, or for the combined company’s acts or for the acts of the combined company’s customers that were in compliance with all applicable laws and regulations at the time such acts were performed. Any of these laws and regulations could result in claims, fines or expenditures that could be material to the combined company’s business, results of operations, financial condition and cash flows.

Environmental laws and regulations, and the interpretation and enforcement thereof, frequently change, and have tended to become more stringent over time. New laws and regulations may have a material adverse effect on the combined company’s customers by limiting or curtailing their exploration, drilling and production activities, which may adversely affect the combined company’s operations by limiting demand for the combined company’s products and services. Additionally, the implementation of new laws and regulations may have a material adverse effect on the combined company’s operating results by requiring the combined company to its operations or products or shut down some or all of its facilities.

Numerous proposals have been made, and are likely to continue to be made, at various levels of government to monitor and limit emissions of greenhouse gases (“GHG”). Past sessions of the U.S. Congress considered, but did not enact, legislation to address climate change. The EPA and other federal agencies previously issued regulations that aim to reduce GHG emissions; however, the current administration has generally indicated an interest in scaling back or rescinding regulations addressing GHG emissions, including those affecting the U.S. oil and gas industry. It is difficult to predict the extent to which such policies will be implemented or the outcome of any related litigation. Any regulation of GHG emissions could result in increased compliance costs or additional operating restrictions for the combined company and/or its customers and limit or curtail exploration, drilling and production activities of the combined company’s customers, which could directly or indirectly, through reduced demand for the combined company’s products and services, adversely affect the combined company’s business, results of operations, financial condition and cash flows.

The combined company’s growth and results of operations may be adversely affected if it is unable to complete third party acquisitions on acceptable terms.

Over time, it is expected that the combined company will acquire value creating, add-on capabilities that broaden its existing technological, geographic and cost position, thereby complementing the combine company’s businesses. However, there can be no assurance that the combined company will be able to find suitable opportunities to purchase or to acquire such capabilities on acceptable terms. If the combined company is unsuccessful in its acquisition efforts, its revenue growth could be adversely affected. In addition, the combined company will face the risk that a completed acquisition may underperform relative to expectations. The combined company may not achieve the synergies originally anticipated, may become exposed to unexpected liabilities, or may not be able to sufficiently integrate completed acquisitions into its then current business and growth model. These factors could potentially have an adverse impact on the combined company’s business, results of operations, financial condition and cash flows.

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The combined company’s products will be used in operations that are subject to potential hazards inherent in the oil and gas industry and, as a result, it is exposed to potential liabilities that may affect its financial condition and reputation.

Apergy’s products are, and the combined company’s products will be, used in potentially hazardous drilling, completion and production applications in the oil and gas industry where an accident or a failure of a product can potentially have catastrophic consequences. Risks inherent in these applications, such as equipment malfunctions and failures, equipment misuse and defects, explosions, blowouts and uncontrollable flows of oil, natural gas or well fluids can cause personal injury, loss of life, suspension of operations, damage to formations, damage to facilities, business interruption and damage to or destruction of property, surface and drinking water resources, equipment and the environment. While Apergy currently maintains insurance protection against some of these risks and seek to obtain indemnity agreements from its customers requiring them to hold it harmless from some of these risks, Apergy’s current insurance and contractual indemnity protection may not be sufficient or effective enough to protect it under all circumstances or against all risks. The occurrence of a significant event not fully insured or indemnified against, or the failure of a customer to meet its indemnification obligations to Apergy could adversely affect Apergy’s business, results of operations, financial condition and cash flows.

The combined company’s industry is undergoing continuing consolidation that may impact its results of operations.

The oil and gas industry continues to experience consolidation and as a result, some of Apergy’s largest customers have consolidated and are using their size and purchasing power to seek economies of scale and pricing concessions. This consolidation may result in reduced capital spending by some of the combined company’s customers or the acquisition of one or more of the combined company’s primary customers, which may lead to decreased demand for the combined company’s products and services. There is no assurance that the combined company will be able to maintain its level of sales to a customer that has consolidated, or replace that revenue with increased business activity with other customers. As a result, the acquisition of one or more of the combined company’s primary customers may have a significant adverse impact on the combined company’s business, results of operations, financial condition and cash flows. Apergy is unable to predict what effect consolidations in the industry may have on prices, capital spending by the combined company’s customers, the combined company’s selling strategies, the combined company’s competitive position, the combined company’s ability to retain customers or the combined company’s ability to negotiate favorable agreements with its customers.

Apergy and the ChampionX Business are subject to information technology, cybersecurity and privacy risks.

Apergy depends on, and the combined company will depend on, various information technologies and other products and services to store and process information and otherwise support its business activities. Apergy also manufactures and sells hardware and software to provide monitoring, controls and optimization of customer critical assets in oil and gas production and distribution. In addition, certain of ChampionX’s customer offerings include digital components, such as remote monitoring of certain customer operations. Apergy also provides services to maintain these systems. Additionally, Apergy’s operations rely, and the combined company’s operations will rely, upon partners, vendors and other third-party providers of information technology and other products and services. If any of these information technologies, products or services are damaged, cease to properly function, are breached due to employee error, malfeasance, system errors, or other vulnerabilities, or are subject to cybersecurity attacks, such as those involving unauthorized access, malicious software and/or other intrusions, Apergy and the combined company or their respective partners, vendors or other third parties could experience: (i) production downtimes, (ii) operational delays, (iii) the compromising of confidential, proprietary or otherwise protected information, including personal and customer data, (iv) destruction, corruption, or theft of data, (v) security breaches, (vi) other manipulation, disruption, misappropriation or improper use of its systems or networks, (vii) financial losses from remedial actions, (viii) loss of business or potential liability, (ix) adverse media coverage, and (x) legal claims or legal proceedings, including regulatory investigations and actions, and/or damage to its reputation. While Apergy and ChampionX attempt to mitigate these risks by employing a number

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of measures, including employee training, technical security controls and maintenance of backup and protective systems, Apergy’s, the combined company’s and each of their respective partners’, vendors’ and other third-parties’ systems, networks, products and services remain potentially vulnerable to known or unknown cybersecurity attacks and other threats, any of which could have a material adverse effect on Apergy’s or the combined company’s business, results of operations, financial condition and cash flows.

The combined company will be subject to risks relating to existing international operations and expansion into new geographical markets.

The combined company will focus on expanding sales globally as part of its overall growth strategy and expect sales from outside the United States to continue to represent a significant portion of its revenue. Apergy’s and the combined company’s international operations and Apergy’s global expansion strategy are subject to general risks related to such operations, including:

If the combined company is unable to successfully manage the risks associated with expanding its global business or adequately manage operational risks of its existing international operations, these risks could have a material adverse effect on the combined company’s growth strategy into new geographical markets, the combined company’s reputation, the combined company’s business, results of operations, financial condition and cash flows.

The combined company’s reputation, ability to do business and results of operations may be impaired by improper conduct by or disputes with any of its employees, agents or business partners and it will have an increased compliance burden with respect to, and risk of violations of, anti-bribery, trade control, trade sanctions, anti-corruption and similar laws.

Apergy’s operations require, and the combined company’s operations will require, it to comply with a number of U.S. and international laws and regulations, including those governing payments to government officials, bribery, fraud, anti-kickback and false claims, competition, export and import compliance, money laundering and data privacy, as well as the improper use of proprietary information or social media. In particular, Apergy’s international operations are, and the combined company’s international operations will be, subject to the regulations imposed by the Foreign Corrupt Practices Act and the United Kingdom Bribery Act 2010 as well as anti-bribery and anti-corruption laws of various jurisdictions in which Apergy operates. While Apergy strives to maintain high standards, it cannot provide assurance that its internal controls and compliance systems will always

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protect it from acts committed by Apergy’s or the combined company’s employees, agents or business partners that would violate such U.S. or international laws or regulations or fail to protect Apergy’s and the combined company’s confidential information. Any such violations of law or improper actions could subject the combined company to civil or criminal investigations in the United States or other jurisdictions, could lead to substantial civil or criminal, monetary and non-monetary penalties and related stockholder lawsuits, could lead to increased costs of compliance and could damage the combined company’s reputation, business, results of operations, financial condition and cash flows. ChampionX’s significant international business will increase corruption risks for the combined company, relative to Apergy as a standalone company.

Additionally, Apergy conducts, and the combined company will conduct, some operations through joint ventures in which unaffiliated third parties may control or have significant influence on the operations of the joint venture. As with any joint venture arrangement, differences in views among the joint venture participants may result in delayed decisions, the joint venture operating in a manner that is contrary to Apergy’s preference or in failures to agree on major issues. These factors could have a material adverse effect on the business and results of operations of Apergy’s joint ventures and, in turn, Apergy’s or the combined company’s business and consolidated results of operations.

Tariffs and other trade measures could adversely affect the combined company’s results of operations, financial position and cash flows.

In 2019, the U.S. government continued to impose tariffs on steel and aluminum and a broad range of other products imported into the United States. In response to the tariffs imposed by the U.S. government, the European Union, Canada, Mexico, India and China have announced tariffs on U.S. goods and services. The new tariffs have increased Apergy’s material input costs, and any further trade restrictions, retaliatory trade measures and additional tariffs could result in higher input costs to the combined company’s products. The combined company may not be able to fully mitigate the impact of these increased costs or pass price increases on to its customers. While tariffs and other retaliatory trade measures imposed by other countries on U.S. goods have not yet had a significant impact on Apergy’s business or results of operations, it cannot predict further developments, and such existing or future tariffs could have a material adverse effect on the combined company’s results of operations, financial position and cash flows.

Changes in domestic and foreign governmental laws, regulations and policies, risks associated with emerging markets, changes in statutory tax rates and laws, and unanticipated outcomes with respect to tax audits could adversely affect the combined company’s business, profitability and reputation.

Apergy’s and the combined company’s domestic and international sales and operations are subject to risks associated with changes in laws, regulations and policies (including environmental and employment regulations, export/import laws, tax policies such as export subsidy programs and research and experimentation credits, carbon emission regulations and other similar programs). Failure to comply with any of the foregoing laws, regulations and policies could result in civil and criminal, monetary and non-monetary penalties, as well as damage to Apergy’s reputation. In addition, Apergy cannot provide assurance that its costs of complying with new and evolving regulatory reporting requirements and current or future laws, including environmental protection, employment, data security, data privacy and health and safety laws, will not exceed Apergy’s estimates. In addition, Apergy has made investments in certain countries, including Argentina, Australia, Bahrain, Colombia and Oman, and ChampionX has made investments in certain countries, including Angola, Azerbaijan, Equatorial Guinea, Ghana, India, Kazakhstan, Malaysia, Nigeria, Russia, Saudi Arabia and the United Arab Emirates, and the combined company may in the future invest in other countries, any of which may carry high levels of currency, political, compliance, or economic risk. While these risks or the impact of these risks are difficult to predict, any one or more of them could adversely affect the combined company’s business, results of operations and reputation.

Apergy is, and the combined company will be, subject to taxation in a number of jurisdictions. Accordingly, its effective tax rate is impacted by changes in the mix among earnings in countries with differing statutory tax

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rates. A material change in the statutory tax rate or interpretation of local law in a jurisdiction in which the combined company will have significant operations could adversely impact its effective tax rate and impact its financial results. For example, the U.S. bill commonly referred to as the Tax Cuts and Jobs Act (the “Tax Reform Act”), which was enacted on December 22, 2017, significantly changed U.S. tax law by, among other things, imposing a repatriation tax on deemed repatriated earnings of foreign subsidiaries and imposing limitations on the ability to deduct interest expense.

The combined company’s tax returns will be subject to audit and taxing authorities could challenge the combined company’s operating structure, taxable presence, application of treaty benefits or transfer pricing policies. If changes in statutory tax rates or laws or audits result in assessments different from amounts estimated, then Apergy’s business, results of operations, financial condition and cash flows may be adversely affected. In addition, changes in tax laws could have an adverse effect on Apergy’s customers, resulting in lower demand for Apergy’s products and services.

Failure to attract, retain and develop personnel for key management could have an adverse effect on the combined company’s results of operations, financial condition and cash flows.

The combined company’s growth, profitability and effectiveness in conducting its operations and executing its strategic plans depend in part on its ability to attract, retain and develop qualified personnel, align them with appropriate opportunities for key management positions and support for strategic initiatives. Additionally, during periods of increased investment in the oil and gas industry, competition to hire may increase and the availability of qualified personnel may be reduced. If the combined company is unsuccessful in its efforts to attract and retain qualified personnel, the combined company’s business, results of operations, financial condition, cash flows, market share and competitive position could be adversely affected. Additionally, the combined company could miss opportunities for growth and efficiencies.

The credit risks of the combined company’s customer base could result in losses.

Many of the combined company’s customers will be oil and gas companies that have faced or may in the future face liquidity constraints during adverse commodity price environments. These customers impact the combined company’s overall exposure to credit risk as they are also affected by prolonged changes in economic and industry conditions such as the current downturn in the oil and gas industry as a result of the lower crude oil and nature gas price environment. If a significant number of the combined company’s customers experience a prolonged business decline or disruptions, the combined company may incur increased exposure to credit risk and bad debts.

The loss of one or more significant customers could have an adverse impact on the combined company’s financial results.

The combined company’s customers will represent a combination of some of the largest operators in the oil and gas drilling and production markets, including major integrated, large, medium and small independents, and foreign national oil and gas companies, as well as oilfield equipment and service providers. In 2019, Apergy’s top 10 customers represented approximately 41% of total revenue. No customer accounted for net sales equal to 10 percent or more of Apergy’s total revenues for the years ended December 31, 2019, 2018 and 2017. In 2019, ChampionX’s top 10 customers represented approximately 43% of ChampionX combined net sales. No customer accounted for net sales equal to 10 percent or more of ChampionX’s total revenues for the years ended December 31, 2019, 2018 and 2017. While Apergy and ChampionX are not dependent on any one customer or group of customers, the loss of one or more of its significant customers could have an adverse effect on the combined company’s business, results of operations, financial condition and cash flows.

The inability to protect or obtain patent and other intellectual property rights could adversely affect the combined company’s revenue, operating profits and cash flows.

Apergy owns, and the combined company will own, patents, trademarks, licenses and other intellectual property related to its products and services, and Apergy continuously invests, and the combined company will continuously

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invest, in research and development that may result in innovations and intellectual property rights. Apergy employs, and the combined company will employ, various measures to develop, maintain and protect its innovations and intellectual property rights. These measures may not be effective in capturing intellectual property rights, and they may not prevent Apergy’s or the combined company’s intellectual property from being challenged, invalidated, circumvented, infringed, misappropriated or otherwise violated, particularly in countries where intellectual property rights are not highly developed or protected. Unauthorized use of Apergy’s or the combined company’s intellectual property rights and any potential litigation Apergy or the combined company may initiate or have initiated against it in respect of its respective intellectual property rights could adversely impact Apergy’s or the combined company’s competitive position and have a negative impact on Apergy’s or the combined company’s business, results of operations, financial condition and cash flows.

A deterioration in the combined company’s future expected profitability or cash flows could result in an impairment of its recorded goodwill and intangible assets.

Apergy has significant goodwill and intangible assets recorded on its consolidated balance sheet. The valuation and classification of these assets and the assignment of useful lives to intangible assets involve significant judgments and the use of estimates. Impairment testing of goodwill and intangible assets requires significant use of judgment and assumptions, particularly as it relates to the determination of fair market value. A decrease in the long-term economic outlook and future cash flows of the combined company’s business could significantly impact asset values and potentially result in the impairment of intangible assets, including goodwill. In the first quarter ended March 31, 2020, Apergy and ChampionX (with Ecolab), performed an impairment assessment triggered by the substantial decline in oil prices and COVID-19 pandemic. Based on the preliminary analysis, Apergy recorded an impairment of goodwill and long-lived assets in its Production & Automation Technologies segment in the first quarter of 2020. The final computation of the loss resulting from the impairment calculation is expected to be in a range of $650 million to $750 million. Based on the preliminary analysis, ChampionX estimated goodwill impairment in its Specialty Performance reporting unit would be in a range of $125 million to $175 million, though ChampionX is in the process of finalizing the impairment analysis. The value of the combined company’s business could continue to be unfavorably impacted by steep declines in revenue and order rates to the extent as drilling and production activities would be reduced due to, but not necessarily limited to, sustained unfavorable crude oil prices and lower U.S. rig counts. Accordingly, sustained future economic declines could result in additional impairment charges that could have a material adverse effect on the combined company’s results of operations.

The combined company’s exposure to exchange rate fluctuations on cross-border transactions and the translation of local currency results into U.S. dollars could negatively impact its results of operations.

A portion of Apergy’s business is, and a portion of the combined company’s business will be, transacted and/or denominated in foreign currencies, and fluctuations in currency exchange rates could have a significant impact on Apergy’s results of operations, financial condition and cash flows, which are presented in U.S. dollars. Cross-border

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transactions, both with external parties and intercompany relationships, result in increased exposure to foreign exchange effects. Although the impact of foreign currency fluctuations on Apergy’s results of operations has historically not been material, significant changes in currency exchange rates, principally the Canadian Dollar, Australian Dollar, Argentinian Peso, Omani Rial, Colombian Peso, Euro, British Pound Sterling, Russian Ruble and Brazilian Real could negatively affect Apergy’s results of operations. Additionally, the strengthening of the U.S. dollar potentially exposes Apergy and the combined company to competitive threats from lower cost producers in other countries and could result in unfavorable translation effects as the results of foreign locations are translated into U.S. dollars for reporting purposes.

Effective January 31, 2020, the United Kingdom has formally left the European Union (commonly referred to as “Brexit”). The United Kingdom’s relationship with the European Union will no longer be governed by the European Union Treaties, but instead by the terms of the Withdrawal Agreement agreed between the United Kingdom and the European Union in late 2019. The Withdrawal Agreement provides for a “transition” period, which commenced the moment the United Kingdom left the European Union and is currently set to end on December 31, 2020. At the end of the transition period, there may be significant changes to the United Kingdom’s business environment. While the effects of Brexit will depend on any agreements the United Kingdom makes to retain access to European Union markets or the failure to reach such agreements, the uncertainties created by Brexit, any resolution between the United Kingdom and European Union countries or the failure to reach any such resolutions, could adversely affect the combined company’s relationships with customers, suppliers and could harm the combined company’s business and financial results due to fluctuations in the value of the British pound versus the U.S. dollar, the euro and other currencies. In addition, Brexit could result in delayed deliveries, which may adversely affect the combined company’s internal supply chain and the combined company’s ability to perform under customer contracts.

Natural disasters and unusual weather conditions could have an adverse impact on the combined company’s business.

The combined company’s business could be materially and adversely affected by natural disasters or severe weather conditions. Hurricanes, tropical storms, flash floods, blizzards, cold weather and other natural disasters or severe weather conditions could result in evacuation of personnel, curtailment of services, damage to equipment and facilities, interruption in transportation of products and materials and loss of productivity. For example, certain of the combined company’s manufactured products and components will be manufactured at a single facility, and disruptions in operations or damage to any such facilities could reduce the combined company’s ability to manufacture its products and satisfy customer demand. If the combined company’s customers are unable to operate or are required to reduce operations due to severe weather conditions, the combined company’s business could be adversely affected as a result of curtailed deliveries of its products and services.

The combined company’s indebtedness could adversely affect its financial condition and operating flexibility.

The combined company’s ability to make payments on and to refinance its indebtedness, as well as any future indebtedness that it may incur, will depend upon the level of cash flows generated by its operations, its ability to sell assets, availability under its revolving credit facility and its ability to access the capital markets and/or other sources of financing. The combined company’s ability to generate cash will be subject to general economic, industry, financial, competitive, legislative, regulatory and other factors that are beyond its control. If it is not able to repay or refinance its indebtedness as it becomes due, the combined company may be forced to sell assets or take other disadvantageous actions, including (i) reducing financing in the future for working capital, capital expenditures, acquisitions and general corporate purposes or (ii) dedicating an unsustainable level of cash flow from operations to the payment of principal and interest on the indebtedness. In addition, the combined company’s ability to withstand competitive pressures and to react to changes in the oil and gas industry could be impaired.

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The recent global coronavirus pandemic has led to periods of significant volatility in financial, commodities (including oil and gas) and other markets and could harm the business and results of operations for the combined company.

In December 2019, a coronavirus (COVID-19) was reported in China, and has since spread globally. In March 2020, the World Health Organization declared the coronavirus to be a pandemic. Given the ongoing and dynamic nature of the circumstances, it is difficult to predict the lasting impact of the coronavirus pandemic on the business of the combined company, and there is no guarantee that efforts by the combined company to address the adverse impacts of the coronavirus will be effective. The impact to date has included periods of significant volatility in financial, commodities and other markets, and has resulted in a significant decline in the trading price of Apergy’s common stock. This volatility, if it continues, could have an adverse impact on the combined company’s business, financial condition and results of operations. In particular, global markets for oil and gas have been and may continue to be impacted by the coronavirus pandemic and/or other events beyond the control of the combined company, and further volatility in commodity prices could have a negative impact on the economies of energy-dominant states in which Apergy and ChampionX conduct, and the combined company will conduct, significant business. As demand for oil and gas has declined as a result of the pandemic, Apergy and ChampionX’s customers have implemented various measures to address the decline in demand, including reducing orders for Apergy and ChampionX products and seeking price concessions.

In addition, the United States and other countries have implemented restrictions to address the pandemic, including disruptions or restrictions on Apergy’s and ChampionX’s employees’ ability to travel, and which could include temporary closures of Apergy’s or ChampionX’s facilities or the facilities of their suppliers or customers. Any disruption of the combined company’s facilities, suppliers or customers would likely impact the combined company’s sales and operating results. The extent to which the coronavirus could impact the combined company’s results will depend on future developments, which are highly uncertain and cannot be predicted, including new information concerning the severity of COVID-19 and the actions to contain the novel coronavirus or treat its impact, among others.

The ChampionX Business’ subsidiaries are defendants in pending lawsuits alleging negligence and injury resulting from the use of COREXIT^™ dispersant in response to the Deepwater Horizon oil spill, which could expose the ChampionX Business to monetary damages or settlement costs.

As described in “Information about the ChampionX Business—Legal Proceedings—Matters Related to Deepwater Horizon Incident Response,” certain entities that are or will become subsidiaries of ChampionX upon completion of the Transactions (collectively the “COREXIT Defendants”) are among the defendants in a number of class action and individual plaintiff lawsuits arising from the use of COREXIT^™ dispersant in response to the Deepwater Horizon oil spill, which could expose the ChampionX Business to monetary damages or settlement costs. The plaintiffs in these matters have claimed damages under products liability, tort and other theories.

There currently remain three cases pending against the COREXIT Defendants. It is expected that they will be dismissed pursuant to a November 28, 2012 order granting the COREXIT Defendants’ motion for summary judgment. The ChampionX Business cannot predict whether there will be an appeal of the dismissal, the involvement the ChampionX Business might have in these matters in the future or the potential for future litigation. However, although ChampionX believes it has rights to contribution and/or indemnification from third parties in connection with these lawsuits, if an appeal by plaintiffs in these lawsuits is brought and won, these suits could have a material adverse effect on the ChampionX Business and its financial condition, results of operations or cash flows.

The COREXIT Defendants continue to sell the COREXIT^™ oil dispersant product and previously sold product remains in the inventories of individual customers and oil spill response organizations. The ChampionX Business cannot predict the potential for future litigation with respect to such sales or inventory. However, if one or more of such lawsuits are brought and won, these suits could have a material adverse impact on the combined company’s financial results.

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Restrictions imposed by Apergy and the combined company’s debt instruments may limit the ability of the combined company’s subsidiaries to operate their business and to finance their future operations or capital needs or to engage in other business activities.

The terms of the combined company’s debt instruments restrict certain of its subsidiaries from engaging in specified types of transactions. These covenants restrict the ability of Apergy, and its restricted subsidiaries, and upon consummation of the Merger, the combined company and its restricted subsidiaries, among other things, to:

In addition, the debt instruments contain certain financial maintenance covenants. Apergy and the combined company’s ability to comply with these restrictions can be affected by events beyond its control, and Apergy or the combined company may not be able to maintain compliance with them. A breach of any of these covenants would be an event of default.

In the event of a default under any of the debt instruments, the lenders could elect to declare all amounts outstanding under such debt instruments to be immediately due and payable, or in the case of Apergy’s revolving credit facility, may terminate their commitments to lend additional money. If the indebtedness under any of Apergy’s debt instruments were to be accelerated, Apergy and the combined company’s assets may not be sufficient to repay such indebtedness in full. In addition, Apergy’s senior secured credit facilities are secured by substantially all of Apergy’s and its domestic subsidiaries’ assets. If an event of default occurs under Apergy’s debt instruments, the lenders could exercise their rights under the related security documents, and an event of default may be triggered under other debt instruments. Any acceleration of amounts due under Apergy’s debt instruments or the substantial exercise by the lenders of their rights under the security documents would have a material adverse effect on Apergy or the combined company.

Apergy has identified material weaknesses in internal control over financial reporting and, as a result, its internal control over financial reporting and disclosure controls and procedures are not effective.

Apergy has identified material weaknesses in its internal control over financial reporting as a result of which Apergy management has concluded that its internal control over financial reporting and its disclosure controls and procedures were not effective as of December 31, 2019. A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting, such that there is a reasonable possibility that a material misstatement of the company’s annual or interim financial statements will not be prevented or detected on a timely basis. These material weaknesses relate to (a) the ineffective control environment due to a lack of a sufficient complement of personnel with the appropriate level of knowledge, experience and training at Apergy’s Artificial Lift business, (b) ineffective risk assessment component of internal control related to Apergy’s ESP subsidiary (which is part of the Artificial Lift business) as controls were not appropriately designed to ensure that the subsidiary, which was experiencing significant growth and turnover of personnel, had the proper resources to operate a complex business model, (c) a lack of controls designed and maintained within certain of the Artificial Lift businesses over the completeness, accuracy, occurrence or cut-off of revenue and within ESP over the valuation of accounts receivable, (d) a lack of controls maintained to ensure that journal

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entries were properly prepared with appropriate supporting documentation or were reviewed and approved appropriately to ensure the accuracy of journal entries at ESP, (e) a lack of controls designed and maintained over the completeness, accuracy, and existence or presentation and disclosure of inventory and fixed assets at ESP, and (f) a lack of controls designed and maintained over user roles within the general ledger system across Apergy, which defines the actions an individual can perform within the system.

Apergy management is currently in the process of developing and implementing a remediation plan to address these material weaknesses. Apergy expects to incur significant additional expenses in connection with implementing remedial measures. If these remedial measures are insufficient to address the material weaknesses, or if additional material weaknesses or significant deficiencies in its internal control over financial reporting are identified or subsequently arise, Apergy’s or the combined company’s consolidated financial statements may contain material misstatements, and Apergy or the combined company may be required to restate its financial results, which could have a material adverse effect on its financial condition, results of operations or cash flows, restrict the ability to access the capital markets, require significant resources to correct the material weaknesses or deficiencies, subject Apergy or the combined company to fines, penalties or judgments, harm its reputation or otherwise cause a decline in investor confidence and cause a decline in the market price of its stock.

If securities or industry analysts who cover Apergy, Apergy’s business or Apergy’s market publish a negative report or change their recommendations regarding Apergy’s stock adversely, Apergy’s stock price and trading volume could decline.

The trading market for Apergy common stock is influenced by the research and reports that industry or securities analysts publish about Apergy, Apergy’s business, Apergy’s market or Apergy’s competitors. If any of the analysts who cover Apergy or may cover Apergy in the future publish a negative report or change their recommendation regarding Apergy’s stock adversely, or provide more favorable relative recommendations about Apergy’s competitors, Apergy’s stock price would likely decline.

Certain stockholders could attempt to influence changes within Apergy which could adversely affect Apergy’s operations, financial condition and the value of Apergy common stock.

Apergy’s stockholders may from time-to-time seek to acquire a controlling stake in Apergy, engage in proxy solicitations, advance stockholder proposals or otherwise attempt to effect changes. Campaigns by stockholders to effect changes at publicly-traded companies are sometimes led by investors seeking to increase short-term stockholder value through actions such as financial restructuring, increased debt, special dividends, stock repurchases or sales of assets or the entire company. Responding to proxy contests and other actions by activist stockholders can be costly and time-consuming, and could disrupt Apergy’s operations and divert the attention of the Apergy Board of Directors and senior management from the pursuit of its business strategies. These actions could adversely affect Apergy’s operations, financial condition and the value of Apergy common stock.

Anti-takeover provisions contained in Apergy’s certificate of incorporation and bylaws, as well as provisions of Delaware law, could impair a takeover attempt.

Apergy’s certificate of incorporation, bylaws and Delaware law contain provisions that could have the effect of rendering more difficult or discouraging an acquisition deemed undesirable by the Apergy Board of Directors. Apergy’s corporate governance documents include provisions:

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These provisions, alone or together, could delay hostile takeovers and changes in control of Apergy or changes in Apergy’s management.

As a Delaware corporation, Apergy is also subject to provisions of Delaware law, including Section 203 of the Delaware General Corporation Law, which generally prevents certain interested stockholders, including a person who beneficially owns 15% or more of Apergy’s outstanding common stock, from engaging in certain business combinations with Apergy within three years after the person becomes an interested stockholder unless certain approvals are obtained. Any provision of Apergy’s certificate of incorporation or bylaws or Delaware law that has the effect of delaying or deterring a change in control could limit the opportunity for Apergy’s stockholders to receive a premium for their shares of Apergy common stock, and could also affect the price that some investors are willing to pay for Apergy common stock.

The Apergy certificate of incorporation provides that the Court of Chancery of the State of Delaware shall be the exclusive forum for certain disputes between Apergy and its stockholders, which could limit stockholders’ ability to obtain a favorable judicial forum for disputes with Apergy. If this exclusive forum provision is found to be inapplicable or unenforceable, Apergy may not achieve the intended benefits of such provision.

The Apergy certificate of incorporation provides that, unless Apergy’s Board of Directors otherwise determines, the Court of Chancery of the State of Delaware shall be the sole and exclusive forum for each of the following: (1) any derivative action or proceeding brought on behalf of Apergy, (2) any action asserting a claim for breach of a fiduciary duty owed by any director, officer, or stockholder, creditor or constituent of Apergy to Apergy or its stockholders, (3) any action asserting a claim against Apergy or any director or officer of Apergy arising pursuant to any provision of the DGCL, Apergy’s certificate of incorporation or Apergy’s bylaws or (4) any action against Apergy or any director or officer of Apergy asserting a claim governed by the internal affairs doctrine.

This forum selection provision may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable or cost-efficient for disputes with Apergy or any director, officer, employee or agent of Apergy, which may discourage such lawsuits, or increase the costs to a stockholder of bringing such lawsuits, against Apergy and such persons.

The enforceability of forum selection provisions in other companies’ certificates of incorporation, bylaws or similar governing documents has been challenged in legal proceedings, and it is possible that in connection with any action a court could find the forum selection provision contained in Apergy’s certificate of incorporation to be inapplicable or unenforceable in such action. If a court were to find this forum selection provision inapplicable or unenforceable, Apergy may incur additional costs associated with resolving such matters in other jurisdictions, which could adversely impact Apergy’s operating or financial condition or performance.

See the section titled “Comparison of the Rights of Stockholders Before and After The Transactions—Exclusive Forum” beginning on page 244 for more information on this forum selection provision.

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CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including information incorporated by reference into this prospectus, includes “forward-looking statements” as that term is defined in Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended by the Private Securities Litigation Reform Act of 1995, including statements regarding the proposed Transactions between Apergy, ChampionX and Ecolab. These forward-looking statements generally are identified by the words “believe,” “project,” “expect,” “anticipate,” “estimate,” “forecast,” “outlook,” “target,” “endeavor,” “seek,” “predict,” “intend,” “strategy,” “plan,” “may,” “could,” “should,” “will,” “would,” “will be,” “will continue,” “will likely result,” or the negative thereof or variations thereon or similar terminology generally intended to identify forward-looking statements. All statements, other than historical facts, including, but not limited to, statements regarding the expected timing and structure of the proposed Transactions, the ability of the parties to complete the proposed Transactions, the expected benefits of the proposed Transactions, including future financial and operating results and strategic benefits, the tax consequences of the proposed Transactions, and the combined company’s plans, objectives, expectations and intentions, legal, economic and regulatory conditions, and any assumptions underlying any of the foregoing, are forward looking statements.

Important factors that could cause actual results to differ materially from such plans, estimates or expectations include, among others:

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In light of these risks, uncertainties, assumptions and other factors, the forward-looking statements discussed in this prospectus may not occur. Other unknown or unpredictable factors could also have a material adverse effect on each of Ecolab’s, ChampionX’s and Apergy’s actual future results, performance, or achievements. For a further discussion of these and other risks and uncertainties, see the section of this prospectus entitled “Risk Factors.” As a result of the foregoing, readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this prospectus. None of Ecolab, ChampionX or Apergy undertakes, and each expressly disclaims, any duty to update any forward-looking statement whether as a result of new information, future events, or changes in its respective expectations, except as required by law.

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EXCHANGE OFFER

Terms of This Exchange Offer

General

Ecolab is offering to exchange all shares of ChampionX common stock that are owned by Ecolab for shares of Ecolab common stock, at an exchange ratio to be calculated in the manner described below, on the terms and subject to the conditions and limitations described below and in the letter of transmittal and the exchange and transmittal information booklet, each filed as an exhibit to the registration statement of which this prospectus forms a part, that are validly tendered and not properly withdrawn before 12:01 a.m., New York City time, on June 3, 2020, unless this Exchange Offer is extended or terminated. The last day on which tenders will be accepted, whether on June 3, 2020 or any later date to which this Exchange Offer is extended, is referred to in this prospectus as the “expiration date.” You may tender all, some or none of your shares of Ecolab common stock.

Ecolab currently expects that approximately 122.0 million shares of ChampionX common stock will be available in this Exchange Offer. The number of shares of Ecolab common stock that will be accepted for exchange if this Exchange Offer is completed will depend on the final exchange ratio, the number of shares of ChampionX common stock offered and the number of shares of Ecolab common stock tendered.

Ecolab’s obligation to complete this Exchange Offer is subject to important conditions that are described in “—Conditions to Consummation of this Exchange Offer.”

For each share of Ecolab common stock that you validly tender in this Exchange Offer and do not properly withdraw and that is accepted for exchange, you will receive a number of shares of ChampionX common stock at a 10% discount to the per-share value of Apergy common stock, calculated as set forth below, subject to an upper limit of 24.6667 shares of ChampionX common stock per share of Ecolab common stock. Stated another way, subject to the upper limit described below, for each $100 of your Ecolab common stock accepted for exchange in this Exchange Offer, you will receive approximately $111.11 of ChampionX common stock.

The final calculated per-share value and per-share value, as applicable, will be equal to:

The daily VWAP provided by Bloomberg L.P. may be different from other sources of volume-weighted average prices or investors’ or security holders’ own calculations of volume-weighted average prices. Ecolab will determine such calculations of the per-share value of Ecolab common stock and the per-share value of ChampionX common stock, and such determination will be final. Ecolab will maintain a website at http://www.championxexchangeoffer.com that provides the daily VWAP of both Ecolab common stock and Apergy common stock for each day during this Exchange Offer.

If the upper limit on the number of shares of ChampionX common stock that can be received for each share of Ecolab common stock tendered and accepted for exchange is in effect, then the exchange ratio will be fixed at the limit.

Upper Limit

The number of shares of ChampionX common stock you can receive in this Exchange Offer is subject to an upper limit of 24.6667 shares of ChampionX common stock for each share of Ecolab common stock accepted for exchange in this Exchange Offer. If the upper limit is in effect, a stockholder will receive less (and could receive much less) than $111.11 of ChampionX common stock for each $100 of Ecolab common stock that the stockholder

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validly tenders, that is not properly withdrawn and that is accepted for exchange in this Exchange Offer. This upper limit was calculated based on a 21% discount for shares of ChampionX common stock based on the average of the daily VWAPs of Ecolab common stock and Apergy common stock on April 27, 2020, April 28, 2020, and April 29, 2020 (the last three full trading days ending on the second to last full trading day prior to commencement of this Exchange Offer). Ecolab set this limit to ensure that an unusual or unexpected drop in the trading price of Apergy common stock, relative to the trading price of Ecolab common stock, would not result in an unduly high number of shares of ChampionX common stock being exchanged for each share of Ecolab common stock accepted for exchange in this Exchange Offer.

Pricing Mechanism

The terms of this Exchange Offer are designed to result in your receiving $111.11 of ChampionX common stock for each $100 of your Ecolab common stock validly tendered, not properly withdrawn and accepted for exchange in this Exchange Offer based on the calculated per-share values described above. This Exchange Offer does not provide for a minimum exchange ratio because a minimum exchange ratio could result in the shares of ChampionX common stock exchanged for each $100 of Ecolab common stock being valued higher than approximately $111.11. Regardless of the final exchange ratio, the terms of this Exchange Offer would always result in your receiving approximately $111.11 of ChampionX common stock for each $100 of your Ecolab common stock validly tendered, not properly withdrawn and accepted for exchange in this Exchange Offer, so long as the upper limit is not in effect. See the table on page 68 for purposes of illustration.

Subject to the upper limit described above, for each $100 of your Ecolab common stock accepted for exchange in this Exchange Offer, you will receive approximately $111.11 of ChampionX common stock. The following formula will be used to calculate the number of shares of ChampionX common stock you will receive for your shares of Ecolab common stock accepted for exchange in this Exchange Offer:

The calculated per-share value of a share of Ecolab common stock for purposes of this Exchange Offer will equal the simple arithmetic average of the daily VWAP of Ecolab common stock on the NYSE on each of the Valuation Dates. The calculated per-share value of a share of ChampionX common stock for purposes of this Exchange Offer will equal the simple arithmetic average of the daily VWAP of Apergy common stock on the NYSE on each of the Valuation Dates.

To help illustrate the way this calculation works, below are two examples:

Example 1: Assuming that the average of the daily VWAP on the Valuation Dates is $193.2828 per share of Ecolab common stock and $9.9294 per share of Apergy common stock, you would receive 21.6285 (193.2828 divided by 90% of 9.9294) shares of ChampionX common stock for each share of your Ecolab common stock accepted for exchange in this Exchange Offer. In this example, the upper limit of 24.6667 shares of ChampionX common stock for each share of Ecolab common stock would not apply.

Example 2: Assuming that the average of the daily VWAP on the Valuation Dates is $222.2752 per share of Ecolab common stock and $8.4400 per share of Apergy common stock, the upper limit would apply, and you would only

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receive 24.6667 shares of ChampionX common stock for each share of your Ecolab common stock accepted for exchange in this Exchange Offer, because the upper limit is less than 29.2621 (222.2752 divided by 90% of 8.4400) shares of ChampionX common stock for each share of Ecolab common stock.

Indicative Per-Share Values

Indicative exchange ratios, calculated per-share values of Ecolab common stock and calculated per-share values of ChampionX common stock will be made available on each trading day during this Exchange Offer prior to the third Valuation Date, commencing after the close of trading on the third trading day during this Exchange Offer, and may be obtained by contacting the information agent at the toll-free number provided on the back cover of this prospectus or at the website will be maintained at http://www.championxexchangeoffer.com.

Until the first Valuation Date, the indicative calculated per-share values will be calculated as though that day were the expiration date of this Exchange Offer, of (i) Ecolab common stock, which will equal the simple arithmetic average of the daily VWAP of Ecolab common stock, as calculated by Ecolab, on each of the three most recent prior full trading days and (ii) ChampionX common stock, which will equal the simple arithmetic average of the daily VWAP of Apergy common stock, as calculated by Ecolab, on each of the three most recent prior full trading days.

On the first two Valuation Dates, when the values of Ecolab common stock and ChampionX common stock are calculated for the purposes of this Exchange Offer, the indicative calculated per-share values of Ecolab common stock and the indicative calculated per-share values of ChampionX common stock, as calculated by Ecolab, will each equal (i) after the close of trading on the NYSE on the first Valuation Date, the VWAPs for that day, and (ii) after the close of trading on the NYSE on the second Valuation Date, the VWAPs for that day averaged with the VWAPs on the first Valuation Date. On the first two Valuation Dates, the indicative exchange ratios will be updated no later than 4:30 p.m., New York City time. No indicative exchange ratio will be published or announced on the third Valuation Date, but the final exchange ratio will be announced by press release and available on the website by 9:00 a.m., New York City time, on the second trading day immediately preceding the expiration date of this Exchange Offer.

Final Exchange Ratio

The final exchange ratio that shows the number of shares of ChampionX common stock that you will receive for each share of your Ecolab common stock accepted for exchange in this Exchange Offer will be available at http://www.championxexchangeoffer.com and announced by press release by 9:00 a.m., New York City time, on the second to last full trading day prior to the expiration date (that is, on June 1, 2020, unless this Exchange Offer is extended or terminated).

After that time, you may also contact the information agent to obtain the final exchange ratio at its toll-free number provided on the back cover of this prospectus.

Each of the daily VWAPs, calculated per-share values and the final exchange ratio will be rounded to four decimal places.

If Ecolab common stock or Apergy common stock does not trade on any of the Valuation Dates, the calculated per-share value of Ecolab common stock and the calculated per-share value of ChampionX common stock will be determined using the daily VWAP of Ecolab common stock and Apergy common stock on the preceding full trading day or days, as the case may be, on which both Ecolab common stock and Apergy common stock did trade.

Since the final exchange ratio will be announced by 9:00 a.m., New York City time, on the second to last full trading day prior to the expiration date of this Exchange Offer, you will be able to tender or withdraw your shares

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of Ecolab common stock after the final exchange ratio is determined. For more information on validly tendering and properly withdrawing your shares, see “—Procedures for Tendering” and “—Withdrawal Rights.”

For the purposes of illustration, the table below indicates the number of shares of ChampionX common stock that you would receive per share of your Ecolab common stock accepted for exchange in this Exchange Offer, calculated on the basis described above and taking into account the upper limit described above, assuming a range of averages of the daily VWAP of Ecolab common stock and Apergy common stock on the Valuation Dates. The first row of the table below shows the indicative calculated per-share value of Ecolab common stock, the indicative calculated per-share value of ChampionX common stock and the indicative exchange ratio that would have been in effect (and the corresponding indicative calculated value ratio) following the official close of trading on the NYSE on April 29, 2020, based on the daily VWAPs of Ecolab common stock and Apergy common stock on April 27, 2020, April 28, 2020 and April 29, 2020. The table also shows the effects of a 15% increase or decrease in either or both the calculated per-share value of Ecolab common stock and the calculated per-share value of ChampionX common stock based on changes relative to the values of April 29, 2020.

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For example, if the calculated per-share value of Ecolab common stock was $210.31 (the highest closing price for Ecolab common stock on the NYSE during the three-month period ending on the second to last full trading day prior to commencement of this Exchange Offer) and the calculated per-share value of ChampionX common stock was $3.02 (the lowest closing price for Apergy common stock on the NYSE during that three-month period), the value of ChampionX common stock, based on the Apergy common stock price, received for shares of Ecolab common stock accepted for exchange in this Exchange Offer would be approximately $35 for each $100 of Ecolab common stock accepted for exchange in this Exchange Offer.

If the trading price of Ecolab common stock were to increase during the last two full trading days prior to the expiration of this Exchange Offer, the average per-share value of Ecolab common stock used to calculate the exchange ratio would likely be lower than the closing price of Ecolab common stock on the expiration date of this Exchange Offer. As a result, you would receive fewer shares of ChampionX common stock and, therefore, effectively fewer shares of Apergy common stock, for each $100 of Ecolab common stock than you would have received if that per-share value were calculated on the basis of the closing price of Ecolab common stock on the expiration date of this Exchange Offer. Similarly, if the trading price of Apergy common stock were to decrease during the last two full trading days prior to the expiration of this Exchange Offer, the average per-share value of ChampionX common stock used to calculate the exchange ratio would likely be higher than the closing price of Apergy common stock on the expiration date of this Exchange Offer. This could also result in your receiving fewer shares of ChampionX common stock and, therefore, effectively fewer shares of Apergy common stock, for each $100 of your Ecolab common stock than you would have received if that per-share value were calculated on the basis of the closing price of Apergy common stock on the expiration date of this Exchange Offer.

The number of shares of Ecolab common stock that may be accepted for exchange in this Exchange Offer may be subject to proration. Depending on the number of shares of Ecolab common stock validly tendered, and not properly withdrawn in this Exchange Offer, and the final exchange ratio, determined as described above, Ecolab may have to limit the number of shares of Ecolab common stock that it accepts for exchange in this Exchange Offer through a proration process. Any proration of the number of shares accepted for exchange in this Exchange Offer will be determined on the basis of the proration mechanics described below under “—Proration; Tenders for Exchange by Holders of Fewer than 100 Shares of Ecolab Common Stock.”

This prospectus and related documents are being sent to persons who directly held shares of Ecolab common stock on May 1, 2020 and brokers, banks and similar persons whose names or the names of whose nominees appear on Ecolab’s stockholder list or, if applicable, who are listed as participants in a clearing agency’s security position listing for subsequent transmittal to beneficial owners of shares of Ecolab common stock. This prospectus and related documents are also being sent to participants in the Ecolab Savings Plans whose plan accounts were invested in Ecolab common stock on April 24, 2020, and also persons who acquired shares of Ecolab common stock through the Ecolab Stock Purchase Plan.

Proration; Tenders for Exchange by Holders of Fewer than 100 Shares of Ecolab Common Stock

If, upon the expiration of this Exchange Offer, Ecolab stockholders have validly tendered and not properly withdrawn more shares of Ecolab common stock than Ecolab is able to accept for exchange (taking into account the exchange ratio and the total number of shares of ChampionX common stock owned by Ecolab), Ecolab will accept for exchange the Ecolab common stock validly tendered and not properly withdrawn by each tendering stockholder on a pro rata basis, based on the proportion that the total number of shares of Ecolab common stock to be accepted for exchange bears to the total number of shares of Ecolab common stock validly tendered and not properly withdrawn (rounded to the nearest whole number of shares of Ecolab common stock), and subject to any adjustment necessary to ensure the exchange of all shares of ChampionX common stock being offered by Ecolab in this Exchange Offer, except for tenders of odd lots, as described below.

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Except as otherwise provided in this section, beneficial holders (other than participants in any of the Ecolab Savings Plans) of fewer than 100 shares of Ecolab common stock who validly tender all of their shares will not be subject to proration if this Exchange Offer is oversubscribed. Beneficial holders of 100 or more shares of Ecolab common stock are not eligible for this preference.

Any beneficial holder (other than participants in any of the Ecolab Savings Plans) of fewer than 100 shares of Ecolab common stock who wishes to tender all of such beneficial holder’s shares of Ecolab common stock in this Exchange Offer must complete the section entitled “Proration/Odd-Lot” on the letter of transmittal. If your odd-lot shares are held by a broker for your account, you can contact your broker and request the preferential treatment.

Ecolab will announce the preliminary proration factor for this Exchange Offer at http://www.championxexchangeoffer.com and separately by press release promptly after the expiration of this Exchange Offer. Upon determining the number of shares of Ecolab common stock validly tendered for exchange, Ecolab will announce the final results of this Exchange Offer, including the final proration factor for this Exchange Offer.

Any shares of Ecolab common stock not accepted for exchange in this Exchange Offer as a result of proration or otherwise will be returned to the tendering stockholder promptly after the final proration factor for this Exchange Offer is determined.

For purposes of this Exchange Offer, a “business day” means any day other than a Saturday, Sunday or U.S. federal holiday and consists of the time period from 12:01 a.m. through 12:00 midnight, New York City time.

Fractional Shares

Fractional shares of ChampionX common stock will be issued in the Distribution. ChampionX common stock (including the fractional shares) will be held by the Exchange Offer agent for the benefit of Ecolab stockholders whose shares of Ecolab common stock are accepted for exchange in this Exchange Offer and, if this Exchange Offer is completed but not fully subscribed, for distribution in the clean-up spin-off. If this Exchange Offer is terminated by Ecolab without the exchange of shares (but the conditions to consummation of the Transactions have otherwise been satisfied), Ecolab intends to distribute all shares (including the fractional shares) of ChampionX common stock owned by Ecolab on a pro rata basis to holders of Ecolab common stock, with a record date to be announced by Ecolab. Following the consummation of this Exchange Offer, Merger Sub will be merged with and into ChampionX, whereby ChampionX will continue as the surviving corporation and a wholly owned subsidiary of Apergy. Each share of ChampionX common stock outstanding immediately prior to the effective time of the Merger (except for shares of ChampionX common stock held by ChampionX, which shares will be canceled and cease to exist, and no consideration will be delivered in exchange therefor) will be converted into the right to receive a number of duly authorized, validly issued, fully paid and nonassessable shares of Apergy common stock equal to the Merger Exchange Ratio, such that immediately following the Merger, ChampionX equityholders will own, in the aggregate, approximately 62% of the issued and outstanding Apergy common stock on a fully diluted basis and Apergy equityholders will own, in the aggregate, approximately 38% of the issued and outstanding Apergy common stock on a fully diluted basis. In this conversion of shares of ChampionX common stock into shares of Apergy common stock, no fractional shares of Apergy common stock will be delivered to holders of shares of ChampionX common stock. Instead, holders of shares of ChampionX common stock who would otherwise be entitled to receive a fractional share of Apergy common stock will receive in cash the dollar amount (rounded to the nearest whole cent) determined by multiplying such fraction by the closing price of Apergy common stock on the NYSE on the last business day prior to the effective time of the Merger. The amount received by such holders of shares of ChampionX common stock will be net of any required withholding taxes.

Exchange of Shares of Ecolab Common Stock

Upon the terms and subject to the conditions of this Exchange Offer (including, if this Exchange Offer is extended or amended, the terms and conditions of the extension or amendment), Ecolab will accept for exchange and will

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exchange, for shares of ChampionX common stock owned by Ecolab, the Ecolab common stock validly tendered, and not properly withdrawn, prior to the expiration of this Exchange Offer, promptly after the expiration date.

The exchange of Ecolab common stock tendered and accepted for exchange pursuant to this Exchange Offer will be made only after timely receipt by the Exchange Offer agent of (a) (i) share certificates representing all validly tendered shares of Ecolab common stock (other than DRS shares), in the proper form for transfer or (ii) in the case of shares delivered by book-entry transfer through The Depository Trust Company, confirmation of a book-entry transfer of those shares of Ecolab common stock in the Exchange Offer agent’s account at The Depository Trust Company, in each case pursuant to the procedures set forth in the section below entitled “—Procedures for Tendering,” (b) the letter of transmittal for shares of Ecolab common stock, properly completed and duly executed (which eligible holders of DRS shares may complete through the Exchange Offer agent’s election website), with any required signature guarantees, or, in the case of a book-entry transfer through The Depository Trust Company, an agent’s message and (c) any other required documents.

For purposes of this Exchange Offer, Ecolab will be deemed to have accepted for exchange, and thereby exchanged, shares of Ecolab common stock validly tendered and not properly withdrawn if and when Ecolab notifies the Exchange Offer agent of its acceptance of the tenders of those shares of Ecolab common stock pursuant to this Exchange Offer.

Upon the consummation of this Exchange Offer, Ecolab will deliver to the Exchange Offer agent a book-entry authorization representing (a) all of the shares of ChampionX common stock being exchanged in this Exchange Offer, with instructions to hold those shares of ChampionX common stock as agent for the holders of shares of Ecolab common stock validly tendered, not properly withdrawn and accepted for exchange in this Exchange Offer and (b) in the case of the clean-up spin-off, if any, all of the shares of ChampionX common stock being distributed in the clean-up spin-off to Ecolab stockholders whose shares of Ecolab common stock remain outstanding after the consummation of this Exchange Offer (as described below under “—Distribution of ChampionX Common Stock Remaining After This Exchange Offer”), with instructions to hold those shares of ChampionX common stock as agent for such Ecolab stockholders. Prior to the effective time of the Merger, Apergy will deposit with the Exchange Offer agent for the benefit of persons who received shares of ChampionX common stock in this Exchange Offer (or in the clean-up spin-off, if applicable) evidence in book-entry form representing the shares of Apergy common stock issuable in the Merger.

Upon surrender of the documents required by the Exchange Offer agent, duly executed, each former holder of shares of ChampionX common stock will receive from the Exchange Offer agent in exchange therefor shares of Apergy common stock and/or cash in lieu of fractional shares of Apergy common stock, as the case may be. You will not receive any interest on any cash paid to you, even if there is a delay in making the payment.

If Ecolab does not accept for exchange any tendered shares of Ecolab common stock for any reason pursuant to the terms and conditions of this Exchange Offer, the Exchange Offer agent (a) in the case of shares of Ecolab common stock held in certificated form, will return certificates representing such shares without expense to the tendering stockholder and (b) in the case of shares tendered by book-entry transfer pursuant to the procedures set forth below in the section entitled “—Procedures for Tendering,” will credit such shares to an account maintained within The Depository Trust Company, in each case promptly following expiration or termination of this Exchange Offer.

Procedures for Tendering

Shares Held in Certificated Form/Book-Entry DRS

If you hold certificates representing shares of Ecolab common stock, you must deliver to the Exchange Offer agent at the applicable address provided on the back cover of this prospectus, a properly completed and duly executed letter of transmittal, along with any required signature guarantees and any other required documents and the certificates representing the shares of Ecolab common stock validly tendered.

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If you hold DRS shares of Ecolab common stock you must deliver to the Exchange Offer agent pursuant to one of the methods set forth in the letter of transmittal, a properly completed and duly executed letter of transmittal, along with any required signature guarantees and any other required documents. Since certificates are not issued for DRS shares, you do not need to deliver any certificates representing those shares to the Exchange Offer agent.

Shares Held Through a Bank, Broker or Other Nominee

If you hold shares of Ecolab common stock through a bank, broker or other nominee and wish to tender your shares of Ecolab common stock in this Exchange Offer, you should follow the instructions sent to you separately by that institution. In this case, you should not use a letter of transmittal to direct the tender of your Ecolab common stock. If that institution holds shares of Ecolab common stock through The Depository Trust Company, it must notify The Depository Trust Company and cause it to transfer the shares into the Exchange Offer agent’s account in accordance with The Depository Trust Company’s procedures. The institution must also ensure that the Exchange Offer agent receives an agent’s message from The Depository Trust Company confirming the book-entry transfer of your Ecolab common stock. A tender by book-entry transfer will be completed upon receipt by the Exchange Offer agent of an agent’s message, book-entry confirmation from The Depository Trust Company and any other required documents.

The term “agent’s message” means a message, transmitted by The Depository Trust Company to, and received by, the Exchange Offer agent and forming a part of a book-entry confirmation, which states that The Depository Trust Company has received an express acknowledgment from the participant in The Depository Trust Company tendering the shares of Ecolab common stock which are the subject of the book-entry confirmation, that the participant has received and agrees to be bound by the terms of the letter of transmittal (including the instructions thereto) and that Ecolab may enforce that agreement against the participant.

The Exchange Offer agent will establish an account with respect to the shares of Ecolab common stock at The Depository Trust Company for purposes of this Exchange Offer, and any U.S. eligible institution that is a participant in The Depository Trust Company may make book-entry delivery of shares of Ecolab common stock by causing The Depository Trust Company to transfer such shares into the Exchange Offer agent’s account at The Depository Trust Company in accordance with The Depository Trust Company’s procedure for the transfer. Delivery of documents to The Depository Trust Company does not constitute delivery to the Exchange Offer agent.

Shares Held in Any of the Ecolab Savings Plans or the Ecolab Stock Purchase Plan

Participants in the Ecolab Savings Plans and the Ecolab Stock Purchase Plan should follow the special instructions that are being sent to them by or on behalf of their applicable plan administrator. Such participants should not use the letter of transmittal to direct the tender of shares of Ecolab common stock held in these plans, but should instead use the Exchange Offer election form (i.e., the Trustee Direction Letter for the Ecolab Savings Plans or the Election Form for the Ecolab Stock Purchase Plan) provided to them by or on behalf of their applicable plan administrator. Such participants may direct the applicable plan trustee to tender all, some or none of the shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to their Ecolab Savings Plan and Ecolab Stock Purchase Plan accounts, subject to any limitations set forth in the special instructions provided to them, by the deadline specified in the special instructions sent by or on behalf of the applicable plan administrator.

If this Exchange Offer is oversubscribed, the number of shares of Ecolab common stock that you elect to exchange will be reduced on a pro rata basis. Any proration of the number of shares accepted for exchange in this Exchange Offer will be determined on the basis of the proration mechanics described in “—Proration; Tenders for Exchange by Holders of Fewer than 100 Shares of Ecolab Common Stock.”

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General Instructions

Do not send letters of transmittal and certificates representing Ecolab common stock to Ecolab, Apergy, ChampionX or the information agent. Letters of transmittal for Ecolab common stock and certificates representing Ecolab common stock should be sent to the Exchange Offer agent at an address listed on the letter of transmittal. Trustees, executors, administrators, guardians, attorneys-in-fact, officers of corporations or others acting in a fiduciary or representative capacity who sign a letter of transmittal or any certificates or stock powers must indicate the capacity in which they are signing and must submit evidence of their power to act in that capacity unless waived by Ecolab.

Whether you tender your Ecolab common stock by delivery of certificates or through your broker, the Exchange Offer agent must receive the letter of transmittal for Ecolab common stock and the certificates representing your Ecolab common stock, if applicable, at the address set forth on the back cover of this prospectus prior to the expiration of this Exchange Offer. Alternatively, in case of a book-entry transfer of Ecolab common stock through The Depository Trust Company, the Exchange Offer agent must receive the agent’s message and a book-entry confirmation prior to the expiration of this Exchange Offer.

Letters of transmittal for Ecolab common stock and certificates representing Ecolab common stock must be received by the Exchange Offer agent. Please read carefully the instructions to the letter of transmittal you have been sent. You should contact the information agent if you have any questions regarding tendering your Ecolab common stock.

Signature Guarantees

Signatures on all letters of transmittal for Ecolab common stock must be guaranteed by a firm that is a member of the Securities Transfer Agents Medallion Program, or by any other “eligible guarantor institution,” as such term is defined in Rule 17Ad-15 under the Exchange Act (we refer to each of the foregoing as a U.S. eligible institution), except in cases in which shares of Ecolab common stock are tendered either (1) by a registered stockholder who has not completed the box entitled “Special Transfer Instructions” on the letter of transmittal or (2) for the account of a U.S. eligible institution.

If the certificates representing shares of Ecolab common stock are registered in the name of a person other than the person who signs the letter of transmittal, the certificates must be endorsed or accompanied by appropriate stock powers, in either case signed exactly as the name or names of the registered owner or owners appear on the certificates, with the signature(s) on the certificates or stock powers guaranteed by a U.S. eligible institution.

Guaranteed Delivery Procedures

If you wish to tender shares of Ecolab common stock pursuant to this Exchange Offer but (i) your certificates are not immediately available, (ii) you cannot deliver the shares or other required documents to the Exchange Offer agent before the expiration of this Exchange Offer or (iii) you cannot comply with the procedures for book-entry transfer through The Depository Trust Company on a timely basis, you may still tender your Ecolab common stock, so long as all of the following conditions are satisfied:

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Registered stockholders (including any participant in The Depository Trust Company whose name appears on a security position listing of The Depository Trust Company as the owner of Ecolab common stock) may transmit the notice of guaranteed delivery by e-mail transmission or mail it to the Exchange Offer agent. If you hold Ecolab common stock through a bank, broker or other nominee, that institution must submit any notice of guaranteed delivery on your behalf.

Effect of Tenders

A tender of shares of Ecolab common stock pursuant to any of the procedures described above will constitute your acceptance of the terms and conditions of this Exchange Offer as well as your representation and warranty to Ecolab that (1) you have the full power and authority to tender, sell, assign and transfer the tendered shares (and any and all other shares of Ecolab common stock or other securities issued or issuable in respect of such shares), (2) when the same are accepted for exchange, Ecolab will acquire good and unencumbered title to such shares, free and clear of all liens, restrictions, charges and encumbrances and not subject to any adverse claims, and (3) you have a “net long position” in Ecolab common stock or equivalent securities at least equal to the shares of Ecolab common stock being tendered, within the meaning of Rule 14e-4 under the Exchange Act, and such tender of shares complies with Rule 14e-4 under the Exchange Act.

It is a violation of Rule 14e-4 under the Exchange Act for a person, directly or indirectly, to tender shares of Ecolab common stock for such person’s own account unless, at the time of tender, the person so tendering (1) has a net long position equal to or greater than the amount of (a) shares of Ecolab common stock tendered or (b) other securities immediately convertible into or exchangeable or exercisable for the shares of Ecolab common stock tendered and such person will acquire such shares for tender by conversion, exchange or exercise and (2) will cause such shares to be delivered in accordance with the terms of this prospectus. Rule 14e-4 provides a similar restriction applicable to the tender or guarantee of a tender on behalf of another person.

The exchange of Ecolab common stock validly tendered and accepted for exchange pursuant to this Exchange Offer will be made only after timely receipt by the Exchange Offer agent of (a) (i) certificates representing all physically tendered shares of Ecolab common stock or (ii) in the case of shares delivered by book-entry transfer through The Depository Trust Company, confirmation of a book-entry transfer of those shares of Ecolab common stock in the Exchange Offer agent’s account at The Depository Trust Company, (b) the letter of transmittal for shares of Ecolab common stock, properly completed and duly executed, with any required signature guarantees, or, in the case of a book-entry transfer through The Depository Trust Company, an agent’s message and (c) any other required documents.

Appointment of Attorneys-in-Fact and Proxies

By executing a letter of transmittal as set forth above, you irrevocably appoint Ecolab’s designees as your attorneys-in-fact and proxies, each with full power of substitution, to the full extent of your rights with respect to your shares of Ecolab common stock tendered and accepted for exchange by Ecolab and with respect to any and all other Ecolab common stock and other securities issued or issuable in respect of the Ecolab common stock on or after the expiration of this Exchange Offer. That appointment is effective when and only to the extent that Ecolab deposits the shares of ChampionX common stock for the shares of Ecolab common stock that you have tendered with the Exchange Offer agent. All such proxies will be considered coupled with an interest in the tendered shares of Ecolab common stock and therefore will not be revocable. Upon the effectiveness of such appointment, all prior proxies that you have given will be revoked and you may not give any subsequent proxies (and, if given, they will not be deemed effective). Ecolab’s designees will, with respect to the shares of Ecolab common stock for which the appointment is effective, be empowered, among other things, to exercise all of your voting and other rights as they, in their sole discretion, deem proper. Ecolab reserves the right to require that, in

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order for shares of Ecolab common stock to be deemed validly tendered, immediately upon Ecolab’s acceptance for exchange of those shares of Ecolab common stock, Ecolab must be able to exercise full voting rights with respect to such shares.

Determination of Validity

Ecolab will determine questions as to the validity, form, eligibility (including time of receipt) and acceptance for exchange of any tender of Ecolab common stock, in Ecolab’s sole discretion, and its determination will be final and binding. Ecolab reserves the absolute right to reject any and all tenders of Ecolab common stock that it determines are not in proper form or the acceptance of or exchange for which may, in the opinion of its counsel, be unlawful. In the event a stockholder disagrees with such determination, he or she may seek to challenge such determination in a court of competent jurisdiction. Ecolab also reserves the absolute right to waive any of the conditions of this Exchange Offer, or any defect or irregularity in the tender of any shares of Ecolab common stock. No tender of shares of Ecolab common stock is valid until all defects and irregularities in tenders of shares of Ecolab common stock have been cured or waived. Neither Ecolab nor the Exchange Offer agent, the information agent or any other person is under any duty to give notification of any defects or irregularities in the tender of any shares of Ecolab common stock or will incur any liability for failure to give any such notification. Ecolab’s interpretation of the terms and conditions of this Exchange Offer (including the letter of transmittal and instructions thereto) will be final and binding. Notwithstanding the foregoing, Ecolab stockholders may challenge any such determination in a court of competent jurisdiction.

Binding Agreement

The tender of Ecolab common stock pursuant to any of the procedures described above, together with Ecolab’s acceptance for exchange of such shares pursuant to the procedures described above, will constitute a binding agreement between Ecolab and you upon the terms of, and subject to the conditions to, this Exchange Offer.

The method of delivery of share certificates of Ecolab common stock and all other required documents, including delivery through The Depository Trust Company, is at your option and risk, and the delivery will be deemed made only when actually received by the Exchange Offer agent. If delivery is by mail, it is recommended that you use registered mail with return receipt requested, properly insured. In all cases, you should allow sufficient time to ensure timely delivery.

Partial Tenders

If you tender fewer than all the shares of Ecolab common stock evidenced by any share certificate you deliver to the Exchange Offer agent, then you will need to fill in the number of shares that you are tendering in the table on the second page of the letter of transmittal. In those cases, as soon as practicable after the expiration of this Exchange Offer, the Exchange Offer agent will credit the remainder of the shares of common stock that were evidenced by the certificate(s) but not tendered to a DRS account in the name of the registered holder maintained by Ecolab’s transfer agent. Unless you indicate otherwise in your letter of transmittal, all of the shares of Ecolab common stock represented by share certificates you deliver to the Exchange Offer agent will be deemed to have been validly tendered. No share certificates are expected to be delivered to you, including in respect of any shares delivered to the Exchange Offer agent that were previously in certificated form, except for share certificates representing shares not accepted for exchange in this Exchange Offer.

Treatment of Shares of Ecolab Common Stock Held Under an Ecolab Savings Plan or the Ecolab Stock Purchase Plan

Shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) held for the account of participants in the Ecolab Savings Plans and the Ecolab Stock Purchase Plan are eligible for participation in this Exchange Offer. An Ecolab Savings Plan or Ecolab Stock Purchase Plan participant may direct that all, some or

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none of the shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to his or her account be exchanged, subject to the rules applicable to the Ecolab Savings Plans and the Ecolab Stock Purchase Plan for participating in this Exchange Offer.

The rules applicable to the Ecolab Savings Plans and the Ecolab Stock Purchase Plan may be different than those described in this prospectus. Holders who are tendering shares of Ecolab common stock (or units in respect of shares of Ecolab common stock) allocated to their Ecolab Savings Plan or Ecolab Stock Purchase Plan accounts should refer to the special instructions provided to them by or on behalf of their applicable plan administrator for information that is specific to the Ecolab Savings Plans and the Ecolab Stock Purchase Plan. Ecolab Savings Plan and Ecolab Stock Purchase Plan participants should consult the special instructions together with this prospectus in deciding whether or not to participate in this Exchange Offer with respect to their Ecolab Savings Plan and Ecolab Stock Purchase Plan shares of Ecolab common stock (or units in respect of shares of Ecolab common stock).

Lost, Stolen or Destroyed Certificates

If your certificate(s) representing shares of Ecolab common stock have been mutilated, destroyed, lost or stolen and you wish to tender your shares, you may request assistance with the replacement of the certificate(s) by calling Computershare at 800-322-8325. You may also need to complete an affidavit of lost, stolen or destroyed certificate(s) (that you may request by calling Computershare at 800-322-8325), post a surety bond for your lost, stolen or destroyed shares of Ecolab common stock and pay a service fee. Upon completion of the requirements for replacement of your certificate(s) and upon receipt of the completed applicable letter of transmittal your shares of Ecolab common stock will be considered tendered in this Exchange Offer.

Withdrawal Rights

Shares of Ecolab common stock validly tendered pursuant to this Exchange Offer may be withdrawn at any time before the expiration of this Exchange Offer and unless Ecolab has previously accepted such shares for exchange pursuant to this Exchange Offer, may also be withdrawn at any time after the expiration of 40 business days from the commencement of this Exchange Offer. Once Ecolab accepts Ecolab common stock for exchange pursuant to this Exchange Offer, your tender is irrevocable.

For a withdrawal of shares of Ecolab common stock to be effective, the Exchange Offer agent must receive from you a written notice of withdrawal, in the form made available to you, at one of its addresses or the e-mail address set forth on the back cover of this prospectus, and your notice must include your name and the number of shares of Ecolab common stock to be withdrawn, as well as the name of the registered holder, if it is different from that of the person who tendered those shares.

If certificates have been delivered or otherwise identified to the Exchange Offer agent, the name of the registered holder and the certificate numbers of the particular certificates evidencing the shares of Ecolab common stock must also be furnished to the Exchange Offer agent, as stated above, prior to the physical release of the certificates. If shares of Ecolab common stock have been tendered pursuant to the procedures for book-entry tender discussed in “—Procedures for Tendering,” any notice of withdrawal must specify the name and number of the account at The Depository Trust Company to be credited with the withdrawn shares and must otherwise comply with the procedures of The Depository Trust Company.

Ecolab will decide all questions as to the form and validity (including time of receipt) of any notice of withdrawal, in its sole discretion, and its decision will be final and binding, subject to the rights of the tendering stockholders to challenge Ecolab’s determination in a court of competent jurisdiction. Neither Ecolab nor the Exchange Offer agent, the information agent nor any other person will be under any duty to give notification of any defects or irregularities in any notice of withdrawal or will incur any liability for failure to give any notification.

Any shares of Ecolab common stock properly withdrawn will be deemed not to have been validly tendered for purposes of this Exchange Offer. However, you may re-tender withdrawn shares of Ecolab common stock by