Abstract: A relief valve system which is made up of a valve bowl with inlet housing, a relief valve cartridge, a stop valve system, a releasable securement system, and a manual by-pass valve. The relief valve cartridge is a self-contained relief valve which is easily inserted into a reception area formed in the inlet port housing so as to be in line with the inlet port leading to a high pressure source. The stop valve system includes a spring biased poppet valve with a contact shroud that is placed in contact with the upstream end of the cartridge when the cartridge is inserted into the reception area. When the cartridge is inserted the stop valve is in a non-sealing state with respect to the inlet port. When the cartridge is removed the stop valve shifts to a sealing position. At the time a cartridge is removed for servicing a pretested cartridge is inserted in place of the removed cartridge.

Abstract: A safety and pressure relief valve has a seat at the end of a nozzle, a disk which is axially movable from a closed seat-engaging position to an open position, and a sleeve which is telescopically slidable relative to the disk to define variable orifices downstream of the seat and disk. When the valve initially opens, a flow force characteristic having relatively large slope begins the lift movement of the disk. Immediately after opening, an internal pressure related movement of the diskholder relative to the disk occurs to thereby changes the flow path. The valve performs further opening, discharging and closing sequences with the shifted flowpath. Before reseating, the diskholder regains its initial position relative to the disk. In one embodiment, the disk, nozzle and sleeve are mounted in a cartridge assembly which is detachably connected to a valve bowl or body.

Abstract: A pilot operated relief valve which includes a non-flowing modulated pilot valve and a main valve. The pilot utilizes a torsion device in connection with transducers and valves. The transducers relate variations in pressure within the valve system to the torsion device. The torsion device, in turn, acts to open and close various ports of the pilot valve so as to achieve modulated relief of overpressurized fluid from a pressure system. In addition, the torsion device can be manipulated to provide for easily achieved and accurate set pressure positions.

Abstract: A pilot operated relief valve which includes a non-flowing modulated pilot valve and a main valve. The pilot utilizes a torsion device in connection with transducers and valves. The transducers relate variations in pressure within the valve system to the torsion device. The torsion device, in turn, acts to open and close various ports of the pilot valve so as to achieve modulated relief of overpressurized fluid from a pressure system. In addition, the torsion device can be manipulated to provide for easily achieved and accurate set pressure positions.

Abstract: A frictional damper system particularly suited for use in preventing chatter and flutter in a liquid and two phase flow pressure relief valve. The frictional damper system includes one or more damper bodies each having a vertical through-hole and at least one inclined bore extending from the exterior of the damper body into the vertical through-hole. A friction contact member is positioned within each bore and urged inwardly by a spring device or the like. A portion of the object to be damped, such as the stem of a pressure relief valve, extends through the vertical throughhole. The type of material forming the friction member, the degree of compression by the spring device and the amount of inclination of the bore(s) is such that the vertical compression forces components of the damper spring(s) virtually negate the frictional forces created when the member to be damped moves in a first direction.