Valve with improved piston with elastomer O-ring

摘要

A piston type valve includes a piston moving in a cylindrical seat. The piston is fastened to an operating rod extending along the axis of the cylindrical seat. The perimeter of the piston carries an elastomer O-ring providing the seal between the piston and the cylindrical seat. The piston includes two piston members fixed axially together by clamping means. Each of the two members includes an annular groove of substantially circular arc shaped cross section open toward the groove on the other member. The elastomer O-ring is housed between the two annular grooves and clamped between them by the clamping means.