Ronald E Trammell

US Patent:

62272403, May 8, 2001

Filed:

Oct 13, 1999

Appl. No.:

9/417555

Inventors:

Samuel S. Wu - Houston TX
Ronald Trammell - Tomball TX

Assignee:

National-Oilwell L.P. - Houston TX

International Classification:

F16K 1502

US Classification:

13754319

Abstract:

A unitized check valve assembly comprises: a valve body having a bore therethrough, the bore having an inlet and an outlet, a valve disk engaging said body at said outlet, a valve retainer engaging the body and surrounding the valve disk and the outlet; a first biasing member in compression between the body and the valve retainer; and a second biasing member in compression between the body and the valve disk. The flow passage between the valve seat and the valve is continuous around the circumference of the valve. In a preferred embodiment, the valve body and the valve disk each have a mating surface, the mating surfaces define an interface therebetween, and the interface comprises a portion of a spherical surface.