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. 12)*

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)

December 4, 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 on 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 8,591,836
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 8,591,836
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,591,836
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.95%*
14	TYPE OF REPORTING PERSON IN

_______

*Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 2018, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarter ended September 30, 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 8,591,836
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 8,591,836
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,591,836
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.95%*
14	TYPE OF REPORTING PERSON IN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 8,591,836
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 8,591,836
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,591,836
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.95%*
14	TYPE OF REPORTING PERSON IN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 8,591,836
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 8,591,836
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,591,836
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.95%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 8,591,836
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 8,591,836
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 8,591,836
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[ ]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 4.95%*
14	TYPE OF REPORTING PERSON OO

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 1,348,341
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,348,341
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,348,341
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.78%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 1,117,434
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,117,434
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,117,434
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.64%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 290,753
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 290,753
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 290,753
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.17%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 1,745,991
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,745,991
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,745,991
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.01%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 1,249,955
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 1,249,955
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 1,249,955
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.72%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 784,552
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 784,552
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 784,552
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.45%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 387,878
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 387,878
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 387,878
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.22%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 124,179
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 124,179
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 124,179
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.07%*
14	TYPE OF REPORTING PERSON PN

_____________

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 367,671
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 367,671
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 367,671
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.21%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 184,589
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 184,589
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 184,589
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.11%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 568,469
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 568,469
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 568,469
12	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			[X]
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.33%*
14	TYPE OF REPORTING PERSON PN

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 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 410,905
		9	SOLE DISPOSITIVE POWER 0
		10	SHARED DISPOSITIVE POWER 410,905
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 410,905
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 OO

_______

* Calculated based on 173,601,030 ordinary shares outstanding as of September 30, 2018, as reported in the Issuer's Form 10-Q.

This Amendment No. 12 ("Amendment No. 12") amends and supplements the Schedule 13D filed with the Securities and Exchange Commission on June 30, 2015, 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, as amended by Amendment No. 7 filed on May 1, 2018, as amended by Amendment No. 8 filed on June 1, 2018, as amended by Amendment No. 9 filed on August 15, 2018, as amended by Amendment No. 10 filed on September 11, 2018, and as amended by Amendment No. 11 ("Amendment No. 11") filed on October 30, 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 3, 4, 5 and 6 of the Schedule 13D are hereby amended as follows:

Item 3. Source and Amount of Funds or Other Consideration

Item 3 of the Schedule 13D is hereby amended and supplemented by adding the following information:

On November 20, 2018, Strategic Fund-N acquired 254,092 Shares underlying the Put/Call Options for an aggregate exercise price of $11,726,026.49 in connection with the exercise of such Put/Call Options. The source of the funding for such transaction was the general working capital of Strategic Fund-N. The exercise was done pursuant to the Put/Call Letter Agreement, which established a written plan pursuant to Rule 10b5-1(c) under the Securities Exchange Act of 1934, as amended. Following the exercise of such Put/Call Options, the Put/Call Letter Agreement terminated in accordance with its terms.

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. 12 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 December 6, 2018, the Reporting Persons beneficially owned, in the aggregate, 8,591,836 Shares, representing approximately 4.95% of the Issuer's outstanding Shares (calculated based on 173,601,030 Shares outstanding as of September 30, 2018, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarter ended September 30, 2018). Such Shares include an aggregate of 8,580,717 Shares beneficially owned by the Reporting Persons through direct ownership of Shares, representing approximately 4.94% of the Issuer's outstanding Shares and an additional 11,119 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 December 6, 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 and Strategic Fund-C beneficially and directly owns and has sole voting power and sole dispositive power with regard to 1,348,341; 1,117,434; 290,753; 784,552; 1,745,991; 1,249,955; 387,878; 124,179; 367,671, 184,589, 568,469 and 410,905 Shares, 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 11,119 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) The transaction described above in Item 3 of this Amendment No. 12 is incorporated herein by reference. Set forth on Schedule A, which is also incorporated herein by reference, is a list of all other transactions with respect to the Shares effected subsequent to the filing of Amendment No. 11, inclusive of all transactions effected through 4:00 pm, New York City time, on December 6, 2018. All transactions set forth on Schedule A were effected in the open market. The prices set forth on Schedule A do not include commissions.

On October 29, 2018, Trian Offshore sold 169,687 Shares in the open market at a price of $39.8257. Trian Offshore was previously reported in Amendment No. 11 as selling 167,897 Shares on such date.

(e) As a result of the transactions referred to Item 5(c) above, on December 3, 2018, the Filing Persons ceased to be the beneficial owners of more than 5% of the Issuer's outstanding Shares.

Item 6. Contracts, Arrangements, Understandings or Relationship with Respect to Securities of the Issuer

Item 6 of the Schedule 13D is hereby amended and supplemented by adding the following information:

The disclosure contained above in Item 3 of this Amendment No. 12 is incorporated herein by reference.

[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: December 6, 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