Patent ID: 6042081
Filing Date: 2000-03-28
Classification: F16K,Y10T

Abstract:
A diaphragm operated process flow valve, the valve comprising:a valve body assembly having an inlet, an outlet, and a valve seat;a valve plug for engaging the valve seat and controlling flow between the inlet and outlet;a valve stem coupled to the valve plug, the valve stem extending up through the valve body;an actuator having a diaphragm element operatively associated with the valve stem;an actuator spring having a plurality of active spring coils, the terminal coil adjacent to the diaphragm contacting the diaphragm for varying the opening resistance of the plunger element in the valve seat;a housing surrounding the actuator spring having an internal profile; anda keeper element positionable within the internal profile at selected locations and engageable with the actuator spring to vary the number of active coils of the spring.