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 * SMITH C FRANK   2. Issuer Name and Ticker or Trading Symbol NATCO GROUP INC [NTG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Executive Vice President (Last) (First) (Middle) C/O NATCO GROUP INC., 2950 NORTH LOOP WEST, SUITE 700 3. Date of Earliest Transaction (Month/Day/Year) 09/02/2005 (Street) HOUSTON, TX 77092 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 09/01/2005   M   21,225 A $ 6.27 41,409 (1) D   Common stock 09/01/2005   S   13,800 D $ 21.5 27,609 D   Common stock 09/01/2005   S   3,000 D $ 22 24,609 D   Common stock 09/01/2005   S   1,300 D $ 22.25 23,309 D   Common stock 09/01/2005   S   1,000 D $ 21.51 22,309 D   Common stock 09/01/2005   S   725 D $ 22.42 21,584 D   Common stock 09/01/2005   S   700 D $ 22.35 20,884 D   Common stock 09/01/2005   S   500 D $ 22.3 20,384 D   Common stock 09/01/2005   S   200 D $ 21.52 20,184 D

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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

Stock option (right to buy)

$ 6.27

09/01/2005

M

21,225

12/07/2002(2)

12/07/2010

Common stock

21,225

$ 0

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
SMITH C FRANK C/O NATCO GROUP INC. 2950 NORTH LOOP WEST, SUITE 700 HOUSTON, TX 77092			Executive Vice President

Signatures

Charles Frank Smith		09/02/2005
**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)	Direct ownership includes an aggregate of 5,590 shares purchased through a participant-directed defined contribution employee benefit plan and 11,040 shares of restricted stock subject to performance-based restrictions.
(2)	Options vested in one-quarter increments on the first through fourth anniversaries of the date of grant. Date exercisable given is the date of the first such anniversary for such option. The number indicated represents all currently vested options in this grant.

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