Patent ID: 7690626
Filing Date: 2010-04-06
Classification: F16K

Abstract:
1. A ball valve having self-centering seats, comprising: a valve body defining a valve chamber and having flow ports in fluid communication with said valve chamber, said valve body further defining a seat recess having an annular seat recess surface; a valve ball member having a flow passage therethrough and defining an external generally spherical sealing surface and being rotatably moveable within said valve chamber between an open position with said flow passage in fluid communication with said flow ports and a closed position blocking fluid communication of said flow passage with said flow ports; an annular valve seat member being disposed for movement within said seat recess and having a sealing face in sealing engagement with said external generally spherical sealing surface, said annular valve seat member defining an annular outer peripheral surface of smaller dimension as compared with said annular seat recess surface and being normally disposed in annularly spaced relation with said annular seat recess surface, said annular valve seat member being moveable laterally within said seat recess for optimum sealing engagement with said external generally spherical sealing surface of said valve ball member; an annular seat support member being position for movement within said seat recess and having engagement with said valve seat member; a spring member within said seat recess and having force transmitting engagement with said annular seat support member and urging said annular seat support member and said annular valve seat member toward said valve ball member; an annular face seal member being carried by said annular valve seat member and establishing sealing of said annular valve seat member with said external generally spherical sealing surface of said valve ball member and defining a first pressure responsive area; and an annular seal member establishing sealing of said annular seat support member to said annular valve seat member and defining a second pressure responsive area being greater than said first pressure responsive area, fluid pressure within said valve acting on the area differential of said first and second pressure responsive areas and urging said annular valve seat member to forcible sealing engagement with said external generally spherical sealing surface of said valve ball member.