Abstract: A pressure relief valve which has a body including first and second openings for connection in a line and an interior wall defining a flow-through passageway extending from the first opening to the second opening. The body further includes a chamber having an inlet port and an outlet, the inlet port providing fluid communication between the chamber and the passageway. A guide is removably secured to the body and defines a bore extending into the chamber and an open-ended portion extending away from the chamber. A spindle is slidably disposed in the bore between a first position in which the port is open and a second position in which the disc seats in and closes the port. In the second position, the face of the disc exposed to the fluid in the passageway is recessed from the internal wall a distance no greater than one half the diameter of the passageway. A retention nut is threadingly secured to a portion of the spindle extending into the open-ended portion of the guide.

Abstract: A safety valve for relieving excessive pressure in a fluid system including a valve body having a central chamber, a discharge flow nozzle connected into the chamber having a valve seat on the end of the flow nozzle in the chamber, a valve disc movably mounted in the chamber for movement between a closed position on the nozzle seat and an open position spaced from the nozzle seat, a valve disc holder connected with the valve disc having a deflecting rim circumscribing the valve disc seat provided with an internal outwardly divergent annular deflecting surface, a blowdown ring mounted on the nozzle having an inner ring portion provided with an outer frustoconical deflecting surface substantially parallel with and spaced from the valve disc holder deflecting surface, the blowdown ring including an outer cylindrical rim provided with circumferentially spaced semi-elliptical discharge ports and an internal cylindrical surface substantially parallel with and spaced from the outer cylindrical surface of the valve d

Abstract: A testing system for a pilot operated, pressure relief valve of the type wherein movement of the pilot in response to a predetermined line pressure effects the opening of the pressure relief valve comprising a portable apparatus including a source of test fluid pressure, a flow regulating test valve connected to the test pressure source and a piston in the test valve movable in response to the rate of fluid flow through the test valve. The output end of the test valve is connected to a two branch line, one branch line connecting the test valve to the inlet passage of the pilot and the other branch line connecting the test valve to a trapped fluid pressure chamber of the relief valve which is vented by the opening movement of the pilot. A pressure gauge is also connected to the test valve and a plunger on the piston effects the isolation of the pressure gauge when the piston is moved by the increased flow produced through the test valve by the opening of the pilot.

Abstract: An improved valve seal is provided which utilizes a c-shaped secondary seal. The c-shaped seal is positioned between the valve disc and the valve seat. A retainer locates the c-shaped seal with respect to the disc, retains the seal against the disc and provides a pre-load on the seal as required.