Valve with self-centering seat

摘要

A valve is disclosed having a valve piston slidably movable within a valve casing. The valve also includes a spring biasing the valve piston against a valve seat such that the valve is normally closed, but may be opened when the pressure acting on the valve piston exceeds the biasing force of the spring. In order to assure perfect sealing between the valve piston and the valve seat, the valve seat is formed on a member which is movably mounted in the valve casing by a generally annular elastic element. The elastic element connects the valve seat to the valve casing, as well as a shoulder extending from the valve casing into the valve chamber,d such that an axial clearance exist between the valve seat member and the shoulder, and a radial clearance exists between the valve seat member and the valve casing under all operating conditions of the valve. Such clearances enable the valve seat member to move axially and radially so as to assure perfect sealing between the valve seat and the valve piston.