Check valve

Claim 1

A check valve of the type comprising an annular seat adapted to be mounted in an axially extended fluid-carrying line, a yoke extending axially of the line and seat, a head guide mounted to and extending axially of the yoke, a head having an axially extending slide slidably carried by the yoke head guide and a base adapted to slide axially into and out of fluid-sealing engagement with the seat; a biasing element interposed between the yoke and head to bias the base into engagement with the seat, thereby inhibiting fluid flow in an upstream direction and permitting fluid flow in a downstream direction only when fluid pressure in that downstream direction is sufficient to overcome the biasing effect of the biasing element, a pair of valve sleeves extending, respectively, axially upstream and downstream of the valve seat and having mouths adapted for mating connection with adjacent fluid-carrying structure, each sleeve terminating adjacent the valve seat in a sleeve flange formation having a first surface extending diagonally radially outwardly and axially toward the valve seat and the opposite seat flange, each sleeve flange having a second surface extending radially outwardly in intersecting relationship with the first sleeve flange surface, a seat flange extending radially outwardly between the sleeve flanges, a clamp including a V-shaped collar adapted to fit over the sleeve flange first surfaces and tensioning means for drawing the collar tightly against and over the sleeve flanges so as to urge the sleeves toward the valve seat and toward one another, and gasket means carried between the sleeve flanges and the valve seat to provide a fluid-tight seal between the sleeves and the seat when the collar is drawn tightly around the sleeve flanges, the gasket means being generally U-shaped in cross-sectional configuration, the gasket legs of said U-shaped configuration extending between the seat flange and the respective sleeve flange second surfaces, and the gasket bottom of the U-shaped cross-sectional configuration covering the radial edge of the seat flange and extending between the sleeve flange second surfaces to provide a fluid-tight seal between the valve seat and the valve sleeves, each sleeve flange second surface being provided with at least one annular, axially extending recess located radially inwardly of and spaced apart from the flange periphery, and the gasket being provided with an annular, axially extending embossed portion located radially inwardly of and spaced apart from the gasket periphery and adapted to mate with each sleeve flange second surface recess to encourage proper flange-gasket mating engagement and to further encourage fluid-tight sealing action between the gasket, seat and sleeve.