PENTAIR plc — Director's Dealing 2005

May 17, 2005

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: PENTAIR INC (PNR)
CIK: 0000077360
Period of Report: 2005-05-13

Reporting Person: CATHCART RICHARD J (Director, Vice Chairman)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2005-05-16	Common Stock	S	2000	$43.5	Disposed	126566	Direct
2005-05-16	Common Stock	S	300	$43.32	Disposed	126266	Direct
2005-05-16	Common Stock	S	1800	$43.2	Disposed	124466	Direct
2005-05-16	Common Stock	S	500	$43.07	Disposed	123966	Direct
2005-05-16	Common Stock	S	1500	$43.02	Disposed	122466	Direct
2005-05-16	Common Stock	S	900	$43.29	Disposed	121566	Direct
2005-05-16	Common Stock	S	700	$43.26	Disposed	120866	Direct
2005-05-16	Common Stock	S	300	$43.25	Disposed	120566	Direct
2005-05-16	Common Stock	S	100	$43.21	Disposed	120466	Direct
2005-05-16	Common Stock	S	1900	$43.14	Disposed	118566	Direct
2005-05-13	Common Stock - ESPP	A	22.29	$42.0594	Acquired	5188.605	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	1527.866	Indirect

Footnotes

F1: The reported sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 16, 2005.

F2: End-of-period holdings include shares acquired under a dividend reinvestment plan in exempt transaction not required to be reported pursuant to Section 16(a).

F3: Purchase of shares under the Pentair, Inc. Employee Stock Purchase Plan in exempt transaction pursuant to Rule 16b-3(c).

F4: Shares acquired under this Plan are purchased over a three-day trading period. The price shown is the average purchase price over the trading period.