Edgar Filing: PENTAIR plc

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 8)*

PENTAIR PLC

(Name of Issuer)

Ordinary Shares, nominal value $0.01 per share

(Title of Class of Securities)

G7S00T 104

(CUSIP Number)

Brian L. Schorr, Esq.

Trian Fund Management, L.P.

280 Park Avenue, 41 st Floor

New York, New York 10017

Tel. No.: (212) 451-3000

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

May 30, 2018

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ☐.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The Information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

1	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Nelson Peltz
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 14,001,837
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 14,001,837
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,001,837
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.85%*
14	TYPE OF REPORTING PERSON IN

_______

*Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarter ended March 31, 2018 (the "Form 10-Q").

1	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Peter W. May
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 14,001,837
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 14,001,837
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,001,837
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.85%*
14	TYPE OF REPORTING PERSON IN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON Edward P. Garden
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION United States
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 14,001,837
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 14,001,837
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,001,837
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.85%*
14	TYPE OF REPORTING PERSON IN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Fund Management, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 20-3454182
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 14,001,837
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 14,001,837
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,001,837
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.85%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Fund Management GP, LLC S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 20-3454087
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS AF
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 14,001,837
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 14,001,837
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 14,001,837
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 7.85%*
14	TYPE OF REPORTING PERSON OO

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 20-3453988
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 2,572,277
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 2,572,277
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,572,277
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.44%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Master Fund, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 98-0468601
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 4,382,397
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 4,382,397
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 4,382,397
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 2.46%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Parallel Fund I, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 20-3694154
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 334,504
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 334,504
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 334,504
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.19%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Investment Fund-A, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 27-4180625
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 2,008,726
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 2,008,726
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,008,726
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.13%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Investment Fund-N, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 80-0958490
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 1,438,045
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,438,045
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,438,045
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.81%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Investment Fund II, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 45-4929803
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 902,609
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 902,609
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 902,609
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.51%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Investment Fund-D, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 98-1108184
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 446,245
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 446,245
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 446,245
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.25%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Fund (Sub)-G, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 90-1035117
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 142,866
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 142,866
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 142,866
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.08%*
14	TYPE OF REPORTING PERSON PN

_____________

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Fund-G II, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 46-5509975
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 422,996
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 422,996
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 422,996
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.24%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Fund-G III, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 47-2121971
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 212,365
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 212,365
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 212,365
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.12%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Fund-K, L.P. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 47-5116069
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 654,011
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 654,011
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 654,011
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.37%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

1	NAME OF REPORTING PERSON Trian Partners Strategic Fund-C, Ltd. S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON 98-1327448
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP			(a) [_] (b) [_]
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)			[_]
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		7	SOLE VOTING POWER 0
		8	SHARED VOTING POWER 472,736
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 472,736
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 472,736
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.27%*
14	TYPE OF REPORTING PERSON OO

_______

* Calculated based on 178,386,369 ordinary shares outstanding as of March 31, 2018, as reported in the Issuer's Form 10-Q.

This Amendment No. 8 ("Amendment No. 8") amends and supplements the Schedule 13D filed with the Securities and Exchange Commission on June 30, 2015 (the "Original Statement"), as amended by Amendment No. 1 filed on July 13, 2015, as amended by Amendment No. 2 filed on July 29, 2015, as amended by Amendment No. 3 filed on September 8, 2015, as amended by Amendment No. 4 filed on February 22, 2016, as amended by Amendment No. 5 filed on May 10, 2016, as amended by Amendment No. 6 filed on May 18, 2017, and as amended by Amendment No. 7 ("Amendment No. 7") filed on May 1, 2018 (as amended, the "Schedule 13D"), relating to the Ordinary Shares, nominal value $0.01 per share (the "Shares"), of Pentair plc, an Irish public limited company (the "Issuer"). The address of the principal executive office of the Issuer is 43 London Wall, London, EC2M 5TF, United Kingdom.

Capitalized terms not defined herein shall have the meanings ascribed to them in the Schedule 13D. Except as set forth herein, the Schedule 13D is unmodified.

Items 4 and 5 of the Schedule 13D are hereby amended as follows:

Item 4. Purpose of Transaction

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following information:

The sales of Shares by Reporting Persons reported in this Amendment No. 8 were done for portfolio management purposes.

Item 5. Interest in Securities of the Issuer

Item 5 of the Schedule 13D is hereby amended and supplemented by adding the following information:

(a) As of 4:00 p.m., New York City time, on June 1, 2018, the Reporting Persons beneficially owned, in the aggregate, 14,001,837 Shares, representing approximately 7.85% of the Issuer's outstanding Shares (calculated based on 178,386,369 Shares outstanding as of March 31, 2018, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarter ended March 31, 2018). Such Shares include an aggregate of 13,736,582 Shares beneficially owned by the Reporting Persons through direct ownership of Shares, representing approximately 7.70% of the Issuer's outstanding Shares, an additional 254,092 Shares underlying the Put/Call Options that are held by Strategic Fund-N, representing approximately 0.14% of the Issuer's outstanding Shares, and an additional 11,163 Shares underlying Director Options held by Mr. Garden which he received in connection with his service on the Issuer's Board of Directors and which are currently exercisable, representing approximately 0.01% of the Issuer's outstanding Shares.

(b) As of 4:00 p.m., New York City time, on June 1, 2018, each of Trian Onshore, Trian Offshore, Parallel Fund I, TPSIF II, Strategic Fund-A, Strategic Fund-N, Strategic Fund-D, Fund G, Strategic Fund-G II, Strategic Fund-G III, Strategic Fund-K, Strategic Fund-C and Trian Management beneficially and directly owns and has sole voting power and sole dispositive power with regard to 2,572,277; 4,382,397; 334,504; 902,609; 2,008,726; 1,438,045; 446,245; 142,866; 422,996, 212,365, 654,011, 472,736 and 897 Shares (including the Shares underlying the Put/Call Options), respectively, except to the extent that other Reporting Persons as described in this Item 5 may be deemed to have shared voting power and shared dispositive power with regard to such Shares. Mr. Garden beneficially owns and has sole voting power and sole dispositive power with regard to 11,163 Shares underlying Director Options, except to the extent that other members of the Trian Group as described in this Item 5 may be deemed to have shared voting power and shared dispositive power with regard to such Shares.

(c) Set forth below is a list of all transactions with respect to the Shares effected subsequent to the filing of Amendment No. 7, inclusive of all transactions effected through 4:00 pm, New York City time, on June 1, 2018. All such transactions were effected in a privately negotiated transaction. The prices set forth in the table do not include commissions.

Fund	Date	Shares	Price	Type
Trian Partners, L.P.	5/30/2018	98,065	$ 44.135	Sale
Trian Partners Master Fund, L.P	5/30/2018	1,576,935	$ 44.135	Sale

[INTENTIONALLY LEFT BLANK]

SIGNATURE

After reasonable inquiry and to the best of each of the undersigned knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

Dated: June 1, 2018

TRIAN FUND MANAGEMENT, L.P.
By:	Trian Fund Management GP, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN FUND MANAGEMENT GP, LLC

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS, L.P.
By:	Trian Partners GP, L.P., its general partner

By:	Trian Partners General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS MASTER FUND, L.P.
By:	Trian Partners GP, L.P., its general partner

By:	Trian Partners General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member


TRIAN PARTNERS PARALLEL FUND I, L.P.
By:	Trian Partners Parallel Fund I General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS STRATEGIC INVESTMENT FUND-A, L.P.
By:	Trian Partners Strategic Investment Fund-A GP, L.P., its general partner

By:	Trian Partners Strategic Investment Fund-A General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS STRATEGIC INVESTMENT FUND-N, L.P.
By:	Trian Partners Strategic Investment Fund-N GP, L.P., its general partner

By:	Trian Partners Strategic Investment Fund-N General Partner, LLC., its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS STRATEGIC INVESTMENT FUND II, L.P.
By:	Trian Partners Strategic Investment Fund II GP, L.P., its general partner

By:	Trian Partners Strategic Investment Fund-II General Partner, LLC., its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member


TRIAN PARTNERS STRATEGIC INVESTMENT FUND-D, L.P.
By:	Trian Partners Strategic Investment Fund-D GP, L.P., its general partner

By:	Trian Partners Strategic Investment Fund-D General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS FUND (SUB)-G, L.P.
By:	Trian Partners Investment Fund-G GP, L.P., its general partner

By:	Trian Partners Investment Fund-G General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member

TRIAN PARTNERS STRATEGIC FUND-G II, L.P.
By:	Trian Partners Strategic Fund-G II GP, L.P., its general partner

By:	Trian Partners Strategic Fund-G II General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member



TRIAN PARTNERS STRATEGIC FUND-G III, L.P.
By:	Trian Partners Strategic Fund-G III GP, L.P., its general partner

By:	Trian Partners Strategic Fund-G III General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member


TRIAN PARTNERS STRATEGIC FUND-K, L.P.
By:	Trian Partners Strategic Fund-K GP, L.P., its general partner

By:	Trian Partners Strategic Fund-K General Partner, LLC, its general partner

By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Member


TRIAN PARTNERS STRATEGIC FUND-C, LTD.
By:	/s/ EDWARD P. GARDEN
	Name:	Edward P. Garden
	Title:	Director





/s/NELSON PELTZ Nelson Peltz
/s/PETER W. MAY Peter W. May
/s/EDWARD P. GARDEN Edward P. Garden