Check valves

Abstract

A check valve includes an upper housing defining an inlet of the check valve, a lower housing defining an outlet of the check valve, and a cavity interposed between and defined by the upper and lower housings for fluidly connecting the inlet and the outlet. The check valve further includes a valve member mounted in the cavity to selectively permit fluid flow in a first direction, and prevent fluid backflow in a second direction opposite to the first direction. The valve member includes a valve body and a valve stem portion extending axially through a central axis of the valve body. The valve member may further include a plurality of feet disposed about and extending longitudinally from an outer circumferential perimeter of the valve body.

What is claimed is: 
     
         1 . A check valve, comprising:
 an upper housing having an upstream internal surface and defining an inlet extending through the upstream internal surface;   a lower housing having a downstream internal surface and defining an outlet extending through the downstream internal surface;   a cavity interposed between and defined by the upstream internal surface and the downstream internal surface for fluidly connecting the inlet and the outlet; and   a valve member to selectively permit fluid flow in a first direction from the inlet to the outlet, and prevent fluid backflow in a second direction from the outlet to the inlet, the valve member comprising a valve body and a valve stem portion extending axially through opposing surfaces of the valve body along a central axis of the valve body, the valve stem coupled to the lower housing and the valve body positioned between the upstream internal surface and the downstream internal surface, wherein an entirety of an outer circumferential perimeter of the valve body does not engage against any of the upper housing and the lower housing when an upstream pressure is applied to the valve member and when a downstream pressure is applied to the valve member.   
     
     
         2 . The check valve of  claim 1 , further comprising a plurality of feet extending longitudinally from the outer circumferential perimeter of the valve body. 
     
     
         3 . The check valve of  claim 1 , further comprising a filter member coupled to an inner surface of the upper housing, the filter member being disposed upstream of the valve member. 
     
     
         4 . The check valve of  claim 1 , wherein valve stem is coupled to a portion of the lower housing forming a support portion. 
     
     
         5 . The check valve of  claim 4 , wherein the support portion is aligned with a central longitudinal axis of the check valve. 
     
     
         6 . The check valve of  claim 1 , wherein the upstream internal surface comprises a projection extending into the cavity, the projection being circularly disposed about the central axis of the valve body. 
     
     
         7 . The check valve of  claim 6 , wherein a distal end of the projection forms a sealing surface of the projection configured to be engaged against by the valve member to prevent fluid backflow in a second direction from the outlet to the inlet. 
     
     
         8 . A check valve, comprising:
 an upper housing having an upstream internal surface and defining an inlet extending through the upstream internal surface;   a lower housing having a downstream internal surface, a support portion, and defining an outlet extending through the downstream internal surface; and   a valve member comprising a valve body and a valve stem portion extending axially through opposing surfaces of the valve body along a central axis of the valve body,   the valve member positioned within a cavity formed between the upstream internal surface and the downstream internal surface, and with the valve stem portion coupled to the support portion of the lower housing, such that an outer circumferential perimeter of the valve member is movable toward the downstream internal surface to permit a fluid flow in a first direction through the cavity from the inlet to the outlet, and the outer circumferential perimeter of the valve member is movable toward the upstream internal surface to resist fluid backflow in a second direction through the cavity from the outlet to the inlet.   
     
     
         9 . The check valve of  claim 8 , wherein the support portion comprises a central aperture, and wherein the valve stem portion is positioned within the central aperture. 
     
     
         10 . The check valve of  claim 8 , wherein the support portion protrudes into the cavity from the downstream internal surface. 
     
     
         11 . The check valve of  claim 8 , wherein the lower housing comprises a plurality of axially extending slots forming at least a portion of the outlet extending through the downstream internal surface. 
     
     
         12 . The check valve of  claim 11 , wherein the plurality of axially extending slots extend through the support portion. 
     
     
         13 . The check valve of  claim 8 , wherein the upper housing comprises a projection extending from the upstream internal surface into the cavity, the projection being circularly disposed about the central axis of the valve body. 
     
     
         14 . The check valve of  claim 13 , wherein a distal end of the projection forms a sealing surface of the projection configured to be engaged against by the valve member when the outer circumferential perimeter of the valve member moves toward the upstream internal surface to resist fluid backflow. 
     
     
         15 . The check valve of  claim 8 , wherein the upper housing comprises a rib that extends radially inward from the upstream internal surface. 
     
     
         16 . The check valve of  claim 15 , further comprising a filter member positioned between the valve member and the rib. 
     
     
         17 . The check valve of  claim 8 , wherein a fluid flow path extends between the outer circumferential perimeter of the valve member and an inner peripheral surface of the cavity. 
     
     
         18 . A method of providing a check valve, the method comprising:
 providing a cavity, formed between an upstream internal surface of an upper housing and a downstream internal surface of a lower housing, for fluidly connecting an inlet of the upper housing and an outlet of the lower housing; and   providing a valve member within the cavity to selectively permit fluid flow in a first direction from the inlet to the outlet, and prevent fluid backflow in a second direction from the outlet to the inlet, wherein a valve stem portion of the valve member is coupled to a support portion of the downstream internal surface of the lower housing, such that an outer circumferential perimeter of the valve member is movable toward the downstream internal surface to permit the fluid flow in the first direction, and the outer circumferential perimeter of the valve member is movable toward the upstream internal surface to resist fluid backflow in the second direction.   
     
     
         19 . The method of  claim 18 , wherein providing a valve member within the cavity comprises positioning the valve member between the support portion and a projection extending from the upstream internal surface into the cavity. 
     
     
         20 . The method of  claim 18 , further comprising providing a filter member between the inlet of the upper housing and the cavity.