Abstract: A media assisted flow control valve having a main body provided with an inlet, and outlet, a chamber defining a flow passage connecting the inlet and the outlet, and a main valve seat around the flow passage, a main valve mounted in the chamber and having a seat surface engageable with the main valve seat to open and close the valve, the main valve having a flow passage therethrough and a pilot valve seat formed around the main valve flow passage, a pilot valve mounted for movement in the main valve, the pilot valve having a seat surface engageable with the pilot valve seat in the main valve to open and close the pilot valve, a pilot valve stem connected at one end with the pilot valve and extending at the other end exterior of the valve body, and a spring mounted on the pilot valve stem exterior of the valve body to bias the pilot valve and main valve closed.

Abstract: Method and apparatus for remotely detecting when a safety relief valve is initially opened includes a permanent field fixedly associated with the closure member and a magnetic proximity switch mounted on the housing so that initial movement of the magnetic field causes the magnetic proximity switch to close, indicating that the valve has opened. Adjustment means are provided to calibrate the position of the sensor switch so that initial movement of the closure member from the seat of less than 0.04 inches can be detected without interfering with the operation of the valve.

Abstract: An improved safety relief valve that includes an adjusting ring located on the valve seat member. The adjusting ring has one end located to provide an orifice which will control the area governing the rate of closure or "blow down" of the valve and a much larger peripheral surface which cooperates with a valve member carrier to provide an orifice that governs the force applied to the valve carrier and valve member to lift the valve which has been previously "cracked.