US2307546A - Valve and valve seat - Google Patents

Description

Jan- 5, 1943. J. M. sH|MER 2,307,546 VALVE AND VALVE SEAT Filed July 24. 1940 l alcll\cu dalla u, IU-l0 UNITED STATES PATENT OFFICE VALVE AND VALVE SEAT John M. Shimer, Dallas, Tex., assgnor to Oil Well Supply Company, 'a corporation of New Jersey Application July 24, 1940, Serial No. 347,317

1 Claim.

This invention relates to valves of the character employed in mud pumps or other pumps adapted to uid pump mixtures containing abrasive materials, and relates particularly to an improved form of valve capable of longer periods of uninterrupted use than valves heretofore employed in pumps of this nature.

vMud pump valves of the character to which this invention relates are subject to vary rapid wear owing to the presence of abrasive materials such as sand, etc., contained in the drilling fluid or mud and, therefore, must be replaced after comparatively short periods of time. These valves ordinarily include a tapered metallic seat member for coaction with a similarly tapered valve element. These valves in their closed position have combination sealing areas; one of metal-to-metal contact and the other of a resilient material engaging the tapered metallic seat surface.

The present invention is an improvement over that of Shimer application Serial No. 305,542, led November 21, 1939, and that of United States Patent No. 2,163,472, issued June 20, 1939.

It is an object of the present invention to provide a valve of the above character capable of giving a much longer period of service before requiring replacement.

It is a further object of this invention to provide a valve element having a metallic ring portion engaging the seat, combined with a flexible sealing member adapted to contact the valve seat when the valve is in the closed position.

Another object is to provide a valve seat having two engaging areas in offset relationship so that the useful life of the area contacted by the metal portion of the valve approaches the useful life of the area engaged by the flexible sealing member of the valve.

The invention is illustrated in the accompanying drawing, in which the single figure is a longitudinal section through the valve body and the seat with which it coacts.

Referring to the drawing, a valve disc I having an upper valve stem I I and a lower valve stem I 2 is mounted for coaction with a valve seat I3. The guides 8 and 9 for the oppositely extended stems- II and I2 are shown, but it is to be understood that the valve disc could be guided by a single stem without departing from the scope of this invention. A suitable stop S limits the opening motion of the valve disc I Il, and a spring, as shown, tends to hold the valve closed. The outer edge of the valve disc Ill is beveled to provide an inverted conical surface I4 to coact with a similar conical surface I5 formed on the valve seat I3. This valve seat surface I5 is offset relative to another tapered conical seat portion I6 which is arranged to coact with the resilient insert I1, of rubber or equivalent material, secured within the outer confines of an annular recess I8 formed in the valve body. The exible insert extends outwardly and upwardly, as shown, so that it is self-sealed by the fluid pressure of the pump fluid above the valve disc when it assumes the closed position, as illustrated.

It has been found in practice that this type of resilient insert tends to rupture prematurely by the ever decreasing clearance occasioned by wear on the metallic portion of the seat member which reduces the clearance necessary for the resilient sealing member I'I mounted in the valve I0. The present invention takes advantage of the fact that the resilient sealing member II has, under normal conditions, a marked ability to resist Wear by the abrasive mud-like fluid pumped. It is a particular feature of the invention to so construct and arrange the parts that the life of the coacting metal-to-metal parts approaches the life of the coacting metal-to-resilient-material parts. To this end I increase the more quickly wearing metallic portion I5 to such an extent that its useful life approaches that of the portion I6 which coacts with the resilient element.

In the embodiment of the invention illustrated, this increased life is secured by the provision of the built-up frusta-conical seat portion I5 which is offset from the similar frusto-conical seat portion I6. -The area of the portion I5 is preferably greater than that portion of the surface IB which is engaged by the flexible resilient member I'I. This built-up or oiset portion I5 of the valve seat I3 is not necessarily limited to the valve seat itself, as it could to the same advantage be in the form of a raised portion on the valve disc or any part of the tapered valve which is in metal-to-metal contact as distinguished from the metal-to-resilient-material contact, both of which areas require a seating coaction in order to effect a multiple sealing action of the valve, as disclosed. In this way the normal life of the coacting metal-to-metal portions of the valve disc and seat approaches the normal life of the metal-to-resilient-portion of the same seat. Thus the seat element need not be prematurely or unnecessarily replaced.

I claim:

A valve apparatus such as used for slush pumps having a, multiple sealing action comprisa z,isul,oew

ing a metallic valve seat consisting of two contiguous inverted truncated cone faces inclined at the same angle to the valve axis, one of said faces being oiset inwardly from the other so as to compensate for the Wear to which slush pump valves are subjected due to the high frequency of operation thereof, a metallic truncated cone valve disc having a surface for coaction with the innermost cone face of said seat for effecting a sealing action when the valve contacts said innermost seat, and a nonmetallic flexible member mounted on said valve disc for effecting a sealing contact with the outermost cone face of said seat When the valve disc approaches the closed position relative to said innermost seat.

JOHN M. SHIMER.

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