File No. 333-184151

As filed with the Securities and Exchange Commission on May 20, 2020

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

POST-EFFECTIVE AMENDMENT NO. 2
TO
FORM S-8
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Pentair plc
(Exact name of registrant as specified in its charter)

Regal House, 70 London Road, Twickenham, London, TW13QS United Kingdom

(Address of Principal Executive Offices, including Zip Code)

Pentair plc 2020 Share and Incentive Plan

Pentair plc 2012 Stock and Incentive Plan

(Full title of the plan)

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, 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 provided pursuant to Section 7(a)(2)(B) of the Securities Act.¨

Explanatory note

On May 5, 2020 (the “Effective Date”), the shareholders of Pentair plc (the “Company”) approved the Pentair plc 2020 Share and Incentive Plan (the “2020 Plan”). The total number of the Company’s ordinary shares, nominal value $0.01 per share (the “Ordinary Shares”), that may be granted under the 2020 Plan includes, in addition to 3,285,000 newly reserved Ordinary Shares (included by the Company on a new Registration Statement on Form S-8 filed on May 20, 2020), (a) the number of Ordinary Shares reserved under the Pentair plc 2012 Stock and Incentive Plan (the “2012 Plan”) that were not the subject of outstanding awards under the 2012 Plan as of the Effective Date and (b) any Ordinary Shares subject to outstanding awards under the 2012 Plan as of the Effective Date that would have been replenished to the 2012 Plan’s share reserve after the Effective Date pursuant to the terms of the 2012 Plan, such as upon forfeiture of an award (the Ordinary Shares described in (a) and (b), the “2012 Plan Shares”).

This Post-Effective Amendment No. 2 to the original Registration Statement on Form S-8 (Registration No. 333-184151) (the “Registration Statement”), which registered shares to be issued under the 2012 Plan, is being filed with the U.S. Securities and Exchange Commission (the “SEC”) pursuant to the undertaking in Item 512(a)(1)(iii) of Regulation S-K, which requires the Company to disclose any material change in the plan of distribution as it was originally disclosed in the Registration Statement. This Post-Effective Amendment No. 2 adds the 2020 Plan to the Registration Statement and indicates that the previously registered 2012 Plan Shares may, on and after the Effective Date, be issued under the 2020 Plan. A copy of the 2020 Plan is incorporated herein by reference as an exhibit hereto and an opinion as to the validity of the 2012 Plan Shares issuable under the 2020 Plan is filed as an exhibit hereto.

This Post-Effective Amendment No. 2 to the Registration Statement amends and supplements the items listed below, as they were amended by the Post-Effective Amendment No. 1 filed on June 3, 2014 (the “Post-Effective Amendment No. 1”). No additional Ordinary Shares are being registered hereby. All other items of the Registration Statement, as amended by the Post-Effective Amendment No. 1, are incorporated herein by reference without change (the Registration Statement as amended by the previously filed Post-Effective Amendment No. 1 and this Post-Effective Amendment No. 2, the “Amended Registration Statement”).

The documents constituting Part I of this Amended Registration Statement will be sent or given to the participants in the 2020 Plan as specified by Rule 428(b)(1) under the Securities Act of 1933, as amended (the “Securities Act”). In accordance with Rule 428 and the requirements of Part I of Form S-8, such documents are not being filed with the SEC either as part of this Amended Registration Statement or as prospectuses or prospectus supplements pursuant to Rule 424 under the Securities Act. The Company will maintain a file of such documents in accordance with the provisions of Rule 428. Upon request, the Company will furnish to the SEC or its staff a copy of any or all of the documents included in such file.

Item 3      Incorporation of Documents by Reference

The following documents filed with the SEC pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are incorporated herein by reference and deemed to be a part hereof:

All other documents subsequently filed by the Company pursuant to Section 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a post-effective amendment to this Amended Registration Statement that indicates that all securities offered have been sold or that deregisters all securities that remain unsold shall be deemed to be incorporated by reference in this Amended Registration Statement and to be a part hereof from the date of filing of such documents.

Any statement contained in a document incorporated or deemed incorporated herein by reference shall be deemed to be modified or superseded for the purpose of this Amended Registration Statement to the extent that a statement contained herein or in any subsequently filed document which also is, or is deemed to be, incorporated herein by reference modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this Amended Registration Statement.

Item 4      Description of Securities.

Not applicable.

Item 5      Interests of Named Experts and Counsel.

None.

Item 6      Indemnification of Directors and Officers

Pursuant to the Company’s articles of association, subject to the provisions of, and so far as may be permitted by the Companies Act 2014 of Ireland (as amended), every director or other officer of the Company (other than an auditor) shall be indemnified out of the assets of the Company, against all costs, losses, expenses and liabilities incurred by him or her in the execution and discharge of his or her duties or in relation thereto including any liability incurred by him or her in defending civil or criminal proceedings which relate to anything done or omitted or alleged to have been done or omitted by him or her as an officer or employee of the Company and in which judgment is given in his or her favor (or the proceedings are otherwise disposed of without any finding or admission of any material breach of duty on his part) or in which he or she is acquitted or in connection with any application under any statute for relief from liability in respect of any such act or omission in which relief is granted to him or her by the court; provided, however that the indemnity shall not extend to any liability arising from such person's fraud or dishonesty in the performance of their duties or such officers' conscious, intentional or willful breach of any duty to act in the best interest of the Company.

The Company maintains insurance to reimburse the Company's directors and officers and the directors and officers of the Company’s subsidiaries for charges and expenses incurred by them for wrongful acts claimed against them by reason of their being or having been directors or officers of the Company or any of the Company's subsidiaries.

The Company and Pentair Management Company, a Delaware corporation and subsidiary of the Company, have each entered into indemnification agreements with the directors and officers of the Company that provide for the indemnification of and the advancing of expenses to the indemnitee to the fullest extent (whether partial or complete) permitted under Irish law in the case of the Company, and under the Delaware General Corporation Law, in the case of Pentair Management Company. The indemnification agreements between the Company and the directors and officers of the Company further provide that, to the extent insurance is maintained, the Company will provide continued coverage of the indemnitee under their directors' and officers' liability insurance policies.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers or persons controlling the registrant pursuant to the foregoing provisions, the registrant has been informed that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Item 7      Exemption from Registration Claimed

Not applicable.

Item 8      Exhibits

Exhibit Index

Item 9      Undertakings

(a)           The undersigned Company hereby undertakes:

(1)            To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i)                To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii)               To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii)              To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) of this section do not apply if the registration statement is on Form S-8, and the information required to be included in a post-effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the Company pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in this registration statement; and

(2)            That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)            To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(b)           The undersigned Company hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the Company’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c)           Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the Company pursuant to the foregoing provisions, or otherwise, the Company has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Company of expenses incurred or paid by a director, officer or controlling person of the Company in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the Company will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

SIGNATURES

Pursuant to the requirements of the Securities Act, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this post-effective amendment to the Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Golden Valley, State of Minnesota, on May 20, 2020.

Pursuant to the requirements of the Securities Act, this post-effective amendment to the Registration Statement has been signed by the following persons in the capacities listed below on May 20, 2020.

Exhibit 5

20 May 2020

To:         Board of Directors

Pentair plc

10 Earlsfort Terrace

Dublin 2

D02 T380

Ireland

Dear Sirs

and is subject to the assumptions and qualifications set out below.

Subject to the assumptions and qualifications set out in this Opinion and to any matters not disclosed to us, we are of the opinion that:

For the purpose of giving this Opinion, we assume the following without any responsibility on our part if any assumption proves to have been untrue as we have not verified independently any assumption:

The Registration Statement and the 2020 Plan

Authenticity and bona fides

Accuracy of Searches and Warranties

Solvency and Insolvency

Commercial Benefit

This Opinion is addressed to you in connection with the registration of the Shares with the SEC. We hereby consent to the inclusion of this Opinion as an exhibit to the Registration Statement to be filed with the SEC. In giving this consent, we do not thereby admit that we are in a category of persons whose consent is required under Section 7 of the Securities Act.

Yours faithfully,

SCHEDULE

The Plan Documents

Exhibit 23.2

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement No. 333-184151 on Form S-8 of our reports dated February 25, 2020 relating to the financial statements of Pentair plc and the effectiveness of Pentair plc’s internal control over financial reporting, appearing in the Annual Report on Form 10-K of Pentair plc for the year ended December 31, 2019.

/s/ Deloitte & Touche LLP

Minneapolis, MN

May 20, 2020

Exhibit 24

Power of Attorney

KNOW ALL MEN BY THESE PRESENTS that the undersigned directors of Pentair plc, an entity organized under the laws of Ireland, hereby constitute and appoint John L. Stauch and Karla C. Robertson, and each of them individually, his/her true and lawful attorney-in-fact and agent, with full power of substitution and resubstitution, for him/her and in his/her name, place and stead, in any and all capacities, to sign his/her name as a director of Pentair plc (the “Company”) to this Registration Statement on Form S-8 and any amendments (including post-effective amendments) or supplements thereto, relating to the securities to be offered and sold pursuant to the Pentair plc 2020 Share and Incentive Plan (as such plan may be renamed from time to time) and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission under the Securities Act of 1933, as amended.

The undersigned hereby ratifies and confirms all that said attorneys-in-fact and agents, or each of them, have done or shall lawfully do by virtue of this Power of Attorney.

WITNESS my hand this 20th day of May, 2020.