Patent ID: 6095183
Filing Date: 2000-08-01
Classification: F16K,Y10T

Abstract:
A relief valve, comprising:a valve body having inlet and outlet ports;a valve seat disposed within the valve body between the inlet and outlet ports;a valve having a stem moveable toward and away from said seat to stop communication between said inlet and outlet ports;means normally biasing said valve to seat on said seat, said valve stem having a disk adjacent said seat and being responsive to fluid pressure on the upstream and downstream sides of said seat;bushing means surrounding said valve stem including a wall slidably receiving said disk for forming a bushing pressure chamber around the valve stem adjacent said disk,said bushing wall having control ports,said control ports forming the only fluid communication between the bushing pressure chamber and the outlet port;a fluid passage through said disk communicating upstream fluid pressure with the bushing chamber when the upstream fluid pressure unseats said valve; and,adjustable flow control means supported by the body and coacting with one of the control ports for controlling the fluid flow through said one control port to thereby create a fluid back pressure within said bushing chamber for cooperating with said valve biasing means to close said seat.