Pressure relief and shut-off valve

摘要

A combination valve for relieving excess pressure while also stopping downstream gas flow. A pull-type valve core is mounted within the gas flow passage of a valve body. It includes an actuating plunger operatively connected to a poppet that overlies the valve core and sealingly reciprocates against an upper portion of the valve body. The poppet includes a head portion with a central orifice. The poppet seats against an inner surface of a vented housing which encloses the poppet, valve core and valve body. A spring biases the poppet to its seated position allowing normal gas flow through the central orifice and valve core. Excessive gas pressure will overcome the spring force and allow the excess to vent out the housing. Unseating of the poppet also allows the actuating plunger to close the valve core and stop gas flow to downstream equipment.