Ownership Submission
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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(Print or Type Responses)
1. Name and Address of Reporting Person *
CATHCART RICHARD J
   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)
President, COO Water Tech.
(Last)
(First)
(Middle)
5500 WAYZATA BLVD., SUITE 800		 3. Date of Earliest Transaction (Month/Day/Year)
12/07/2004
(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 12/07/2004   M   50,000 A $ 17.5 170,210 D  
Common Stock 12/07/2004   M   5,046 A $ 19.8125 175,256 D  
Common Stock 12/07/2004   M   45,332 A $ 18.1485 220,588 D  
Common Stock 12/07/2004   M   21,332 A $ 17.47 241,920 D  
Common Stock 12/07/2004   F   74,360 D $ 40.07 167,560 D  
Common Stock 12/07/2004   G V 875 D $ 0 166,685 D  
Common Stock 12/08/2004   S   579 D $ 40.72 166,106 D  
Common Stock 12/08/2004   S   2,000 D $ 40.7 164,106 D  
Common Stock 12/08/2004   S   300 D $ 40.68 163,806 D  
Common Stock 12/08/2004   S   800 D $ 40.67 163,006 D  
Common Stock 12/08/2004   S   800 D $ 40.66 162,206 D  
Common Stock 12/09/2004   S   200 D $ 40.66 162,006 D  
Common Stock 12/09/2004   S   500 D $ 40.65 161,506 D  
Common Stock 12/09/2004   S   100 D $ 40.61 161,406 D  
Common Stock 12/09/2004   S   200 D $ 40.6 161,206 D  
Common Stock 12/09/2004   S   1,000 D $ 40.56 160,206 D  
Common Stock 12/09/2004   S   100 D $ 40.5 160,106 D  
Common Stock 12/09/2004   S   800 D $ 40.49 159,306 D  
Common Stock 12/09/2004   S   800 D $ 40.48 158,506 D  
Common Stock 12/09/2004   S   700 D $ 40.47 157,806 D  
Common Stock 12/09/2004   S   400 D $ 40.46 157,406 D  
Common Stock 12/09/2004   S   1,400 D $ 40.44 156,006 D  
Common Stock 12/09/2004   S   100 D $ 40.43 155,906 D  
Common Stock 12/09/2004   S   1,600 D $ 40.4 154,306 D  
Common Stock 12/09/2004   S   600 D $ 40.39 153,706 D  
Common Stock 12/09/2004   S   1,100 D $ 40.37 152,606 D  
Common Stock 12/09/2004   S   300 D $ 40.36 152,306 D  
Common Stock 12/09/2004   S   6,300 D $ 40.35 146,006 D  
Common Stock 12/09/2004   S   900 D $ 40.34 145,106 D  
Common Stock 12/09/2004   S   800 D $ 40.33 144,306 D  

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
Employee Stock Option (right to buy) $ 17.47 12/07/2004   M     21,332 01/02/2004 01/02/2013 Common Stock 21,332 $ 0 42,668 (1) D  
Employee Stock Option (right to buy) $ 17.5 12/07/2004   M     50,000 01/22/1999 01/22/2008 Common Stock 50,000 $ 0 0 (1) D  
Employee Stock Option (right to buy) $ 18.1485 12/07/2004   M     45,332 01/02/2003 01/02/2012 Common Stock 45,332 $ 0 22,668 (1) D  
Employee Stock Option (right to buy) $ 19.8125 12/07/2004   M     5,046 01/14/2000 01/14/2009 Common Stock 5,046 $ 0 44,954 (1) D  
Employee Stock Option (right to buy) $ 40.07 12/07/2004   A(2)   20,531   12/07/2004(3) 01/02/2012(3) Common Stock 20,531 $ 0 20,531 D  
Employee Stock Option (right to buy) $ 40.07 12/07/2004   A(2)   9,300   12/07/2004(3) 01/02/2013(3) Common Stock 9,300 $ 0 9,300 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
CATHCART RICHARD J
5500 WAYZATA BLVD.
SUITE 800
GOLDEN VALLEY, MN 55416-1259		       President, COO Water Tech.  

Signatures

 Louis L. Ainsworth, Attorney-In-Fact   12/09/2004
**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) 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 stock option and exercise price have been adjusted to reflect the stock split.
(2) Employee reload stock option granted pursuant to the Pentair, Inc. Omnibus Stock Incentive Plan.
(3) Reload stock option becomes exercisable upon grant and expires on the same date as the original option grant.

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