FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * AINSWORTH LOUIS L   2. Issuer Name and Ticker or Trading Symbol PENTAIR INC [PNR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Sr. Vice President, Secretary (Last) (First) (Middle) 5500 WAYZATA BLVD., SUITE 800 3. Date of Earliest Transaction (Month/Day/Year) 01/02/2005 (Street) GOLDEN VALLEY, MN 55416-1259 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 01/03/2005   S(1)   3,000 D $ 43.5 97,849.644 D   Common Stock 01/03/2005   S(1)   1,700 D $ 43.35 96,149.644 D   Common Stock 01/03/2005   S(1)   300 D $ 43.36 95,849.644 D   Common Stock               3,170.001 I By Spouse

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Incentive Bonus Award (cash-only right)

$ 0

01/02/2005

J(2)

210,000

01/02/2005

01/02/2005

Cash-only Right

210,000

$ 0

0 (3)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
AINSWORTH LOUIS L 5500 WAYZATA BLVD. SUITE 800 GOLDEN VALLEY, MN 55416-1259			Sr. Vice President, Secretary

Signatures

Louis L Ainsworth		01/03/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The reported sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on September 22, 2004.
(2)	Payment of vested incentive bonus award based on a fixed value as determined by the Compensation Committee.
(3)	On May 17, 2004, Pentair declared a 2-for-1 stock split in the form of a 100 percent stock dividend payable on June 8, 2004, to shareholders of record as of June 1, 2004. This previously reported derivative security has been adjusted to reflect the stock split.

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