Abstract: A valve assembly, particularly a breather valve assembly for fluid storage tanks, is described. This assembly comprises a valve housing including a fluid conduit and a valve seat defining a fluid outlet of the fluid conduit, and a pressure pallet sized and adapted to move away from the valve seat in response to an increased fluid pressure in the fluid conduit. A seal is provided and acts to effectively seal the fluid outlet against fluid flow from said fluid conduit when the seal is in contact with the valve seat. The seal which includes first and second flexible seal elements which are unsecured to the pressure pallet at or near their respective outer peripheries, is structured so that fluid from the fluid conduit is in the space between the first and second seal elements when the seal means is in contact with the valve seat.

Abstract: A main valve includes a product pressure inlet, an outlet, a movable closure member and a pressurized head volume above the closure member. Product pressure relief flow through the main valve is controlled by a modulating, pressure operated pilot relief valve that includes a piston chamber with a reciprocally mounted pilot piston. The chamber is in fluid communication with the pressurized head volume and with the outlet and inlet of the main valve. An inlet valve controls flow from the inlet of the main valve into the chamber and is actuated by the pilot piston. A vent valve is mounted within the piston chamber and controls fluid flow from the piston chamber to the outlet of the main valve and is actuated by the pilot piston.

Abstract: A main valve includes a product pressure inlet, an outlet, a movable closure member and a pressurized head volume above the closure member. Product pressure relief flow through the main valve is controlled by a modulating, pressure operated pilot relief valve that includes a piston chamber with a reciprocally mounted pilot piston. The chamber is in fluid communication with the pressurized head volume and with the outlet and inlet of the main valve. An inlet valve controls flow from the inlet of the main valve into the chamber and is actuated by the pilot piston. A vent valve is mounted within the piston chamber and controls fluid flow from the piston chamber to the outlet of the main valve and is actuated by the pilot piston. The pilot piston includes first and second surfaces and effective areas exposed to the pressure in the piston chamber and an end isolated from the piston chamber and in fluid communication with the main valve inlet.

Abstract: The pilot valve 206 disclosed utilizes a piston 226 operating intermediate a pressure setting spring 234 and main valve head volume 222 vent valve, and having a single pressure sensing chamber 235. The operating piston includes an elongated extension 229 of reduced diameter extending from the piston adjacent the sensing chamber and incorporates an opposite end, secondary relief chamber 230 providing main valve operation at pressures fixedly related to the operating piston relief setting. The piston extension operates the vent valve 245 in an adjacent chamber. The piston further defines an internal cavity 240 containing a somewhat coaxial inlet valve 251, 252. Inlet and exhaust valves are in fluid communication through said piston extension. Main valve head volume venting and pressurizing is accomplished through valve body ports cooperating with said inlet and exhaust valves.

Abstract: A main valve includes a product pressure inlet, an outlet, a movable closure member and a pressurized head volume above the closure member. Product pressure relief flow through the main valve is controlled by a modulating, pressure operated pilot relief valve that includes a piston chamber with a reciprocally mounted pilot piston. The chamber is in fluid communication with the pressurized head volume and with the outlet and inlet of the main valve. An inlet valve controls flow from the inlet of the main valve into the chamber and is actuated by the pilot piston. A vent valve is mounted within the piston chamber and controls fluid flow from the piston chamber to the outlet of the main valve and is actuated by the pilot piston. The pilot piston includes first and second surfaces and effective areas exposed to the pressure in the piston chamber and an end isolated from the piston chamber and in fluid communication with the main valve inlet.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like.A two-stage, non-flowing valve (5) operates a main relief valve (7) of substantially greater capacity. Flow control elements provided by (35), (36), (38), and (39) associated with the first stage poppet are utilized to provide positive valve operation. In a preferred embodiment the main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to and in fluid communication with the main valve. A flow adapter (100) having a self-cleaning orifice is disposed intermediate said main valve head volume (68) and pilot vent port (1) to provide improved operation of the combination. A ball (16) selector, (24, 15, 76) provides means for conveniently connecting to a field testing either the pilot or the entire valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits and the like.A two-stage, non-flowing valve (5) operates a main relief valve (7) of substantially greater capacity. Flow control elements provided by (35), (36), (38), and (39) associated with the first stage poppet are utilized to provide positive valve operation. In a preferred embodiment the main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to and in fluid communication with the main valve. A flow adapter (100) having a self-cleaning orifice is disposed intermediate said main valve head volume (68) and pilot vent port (1) to provide improved operation of the combination. A ball (16) selector, (24, 15, 76) provides means for conveniently connecting to a field testing either the pilot or the entire valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like. A unique two-stage, non-flowing pilot valve operates a main relief valve of substantially greater capacity. In a preferred embodiment main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to the main valve for operating communication therewith. A particularly unique ball selector provides means for testing both first and second stages without operating the main valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A pilot operated relief valve for use on medium and high pressure vessels, conduits, and the like.A unique two-stage, non-flowing pilot valve (5) operates a main relief valve (7) of substantially greater capacity. Flow control elements provided by 35, 36, 38, and 39 associated with the first stage poppet are utilized to provide positive valve operation. In a preferred embodiment the main valve is mounted directly onto the pressure vessel which is to be vented at a predetermined pressure. The pilot is preferably mounted closely adjacent to the main valve for operating communication therewith. A ball (16) selector, (24, 15, 76) provides means for conveniently connecting to a field testing either the pilot or the entire valve, providing improved setpoint and reset or blowdown adjustments for the overall combination.

Abstract: A pilot operated switching valve includes a sliding spool that is actuated by pilot pressure to control fluid through the valve to a prime mover. The ends of the spool are exposed to pilot pressure that moves the spool within the valve housing to control fluid flow through passages to and from the spool. The passages are sealed by the spool at selected positions to minimize internal leakage and also to allow the valve to hydraulically lock the prime mover. The switching valve also includes a manual switch that is in fluid communication with a source of pressurized fluid. The manual switch may be manually actuated to direct pilot fluid to one of the two ends of the sliding spool thereby manually actuating the valve.

Abstract: A pilot operated switching valve includes a sliding spool that is actuated by pilot pressure to control fluid through the valve to a prime mover. The ends of the spool are exposed to pilot pressure that moves the spool within the valve housing to control fluid flow through passages to and from the spool. The passages are sealed by the spool at selected positions to minimize internal leakage and also to allow the valve to hydraulically lock the prime mover. The switching valve also includes a manual switch that is in fluid communication with a source of pressurized fluid. The manual switch may be manually actuated to direct pilot fluid to one of the two ends of the sliding spool thereby manually actuating the valve.

Abstract: A data acquisition device used to measure fluid level includes a float coupled to a measuring tape. The float includes a body with a first surface defining a first cross-sectional area and a second surface defining a second cross-sectional area; the second cross-sectional area being smaller than the first. A tube extends from the device to a location above the fluid level. The float is positioned within the tube in an orientation wherein the first surface is parallel to the axis of the tube. The float is then lowered to a point outside the tube and pivoted such that the first surface is transverse to the axis of the tube. The float is then lowered to the fluid surface allowing the data acquisition device to record the fluid level.