Irwin A Lewis

US Patent:

40747026, Feb 21, 1978

Filed:

Dec 20, 1976

Appl. No.:

5/752056

Inventors:

Irwin M. Lewis - New Rochelle NY

Assignee:

ACF Industries, Incorporated - New York NY

International Classification:

F16K 3100

US Classification:

13762566

Abstract:

A control valve for bleeding fluid from a valve actuator has a slide valve with a piston on one end thereof mounted for movement within a uniform diameter piston chamber. The piston is movable longitudinally within the piston chamber between a seated position at an outer end of the piston chamber and an unseated set position adjacent the opposite inner end of the chamber. An O-ring is positioned in an annular groove in the inner wall defining the piston chamber adjacent the inner end of the piston chamber and contacts the outer periphery of the piston in fluid-tight sealing relation when the piston is in a raised unseated position adjacent the inner end of the piston chamber. The outer periphery of the piston is spaced from the adjacent inner wall of the piston chamber to permit fluid to pass between the piston and the wall when the piston is out of contact with the O-ring.