Abstract: A pilot operated pressure relief valve for use on medium and high pressure vessels, conduits, and the like. A two-stage, non-flowing pilot valve operates a main relief valve of substantially greater capacity. 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. An improved main valve seal is provided which allows the use of commonly available seal configurations in a simple and easily assembled construction to provide a fast operating, high pressure seal.

Abstract: A pilot valve designed to regulate a main liquid flow valve disposed in a fluid system is disclosed having a diaphragm and sliding poppet assembly which is biased in one direction by a reference force and movable in the opposite direction in response to variances in regulated pressure sensed upon the diaphragm. The pilot valve includes integrally formed self-cleaning restrictors which dampen the operation of the valve to eliminate chatter as the pilot valve throttles to maintain the desired liquid flow level in the fluid system. Stability during operation is provided by a positive feedback force being applied to the pilot poppet which is of the same magnitude as the pressure which positions the valve member of the main flow valve. This positive feedback force significantly reduces phase lag between the pilot and the main flow valve, thereby increasing valve response to load changes.

Abstract: In a valve wherein a flexible tube is stretched around a circular barrier between inlet and outlet slots and is conditioned to enable flow in an annular path around the barrier when upstream pressure overcomes pressure in a control jacket around the tube, the improvement comprising a second flow path directly through the barrier, which is normally closed off by a poppet valve engagable with a seat around the passage. A spring augmented by a control pressure biases the valve toward closed position and is preferably set so that, only after capacity of the flexible tube is reached or approached, does the poppet valve open to answer the need for high pressure demand downstream or for relief of a high pressure surge upstream.

Abstract: A pilot controlled membrane valve for ventilating containers or the like comprises a valve housing having a first valve seat between the inlet and outlet of the housing. First valve means, movable between a closed position engaging said first valve seat and an open position, include a first membrane extending transversely through the housing and defining with the latter to one side of the first valve seat a valve chamber, which is connected by an overpressure passage means to the inlet. The valve includes further a pilot valve having a second seat, second valve means including a second membrane and being movable between a closed position engaging the second valve seat and an open position, a second outlet, means biasing the second valve means to the closed position and chamber means under atmospheric pressure surrounding the biasing means, in which the cross-section of the second valve seat and that of the second outlet is greater than the open cross-section of the overpressure passage means.

Abstract: A milking apparatus automatically providing the appropriate amount of vacuum for purposes of milking a cow throughout the entire milking operation. The milking apparatus includes a fluid control valve system having a controller unit and a discharge valve in fluid communication with a collection jar. The controller unit is further adapted for communication with a source of vacuum, and the collection jar is adapted to be in communication with the cow such that the vacuum can draw milk from the cow into the collection jar. The discharge valve is further adapted for communication with a source of vacuum for drawing the milk through the discharge valve.

Abstract: A safety valve for a pressure vessel, e.g. a marine boiler, comprises a piston-operated valve mounted on the pressure vessel and provided with a cylinder which is connected to a pressure detector. According to the invention, a pair of juxtaposed control valves are provided for selectively opening and blocking communication between the cylinder and the pressure vessel and between the cylinder and the atmosphere, respectively, these control valves being actuated by an element disposed between them and connected by a rod to a control piston which is displaced by the pressure in the vessel against the force of an adjustable spring.

Abstract: Precision gas pressure regulation is disclosed to provide extreme sensitivity, fast response, and positive shut-off of gases for pressurizing a vessel, such as a tank, pressurized room, chamber, duct, and the like, at pressures up to about 2 inches of water column above atmospheric pressure, and as low as about 0.25 inches of water column, with control of pressure within about 0.02 inches of water column within a predetermined pressure within this range. The system is compact, self-contained, and requires no external source of power other than the supply pressure, which can range from about 10 Psig to 1,000 Psig. Redundant pressure relief devices are provided at all points of pressure reduction within the system for maximum safety. Means are provided to prevent condensate build up in internal components, and for uses in which toxic or corrosive gases are contemplated, a purging option permits unwanted material to be swept out of the apparatus.

Abstract: A pressure relief valve of the diaphragm type having a condensate recovery device. The condensate recovery device is connected to the disc of the relief valve and provides means for moving condensate from an upper control chamber to either an inlet chamber or to a discharge chamber depending upon the relative pressures of the inlet and discharge chambers. Condensate from the control chamber enters a passageway in the recovery device through an inlet check valve and flows from the passageway through one of two inlet check valves into another chamber having a pressure higher than the pressure in the passageway. Each of the check valves includes a valve seat connected to one of the chambers and a ball which sits on the seat during the absence of any condensate in the passageway. Any condensate in the control chamber causes the ball at the inlet valve to float off the inlet seat and allows the condensate to enter the passageway.

Abstract: The present invention relates to an arrangement in or relating to a valve comprising a housing having an inlet and an outlet whose interconnection is closable by means of a differential piston slidably arranged in a cylinder in the housing, said differential piston being equipped with a bore interconnecting its large and small sides, said valve further comprising a conduit or the like leading from the chamber in the housing on the large side of the differential piston to the outlet, said conduit or the like being equipped with a pilot valve for closing and opening of the conduit. Valves of this type may be used for irrigation purposes in agriculture. By controlling the pilot valve of the valve by means of for instance a timer, the valve may automatically be brought to open for the water supply to the spreaders at a predetermined time and again to close the water supply when the irrigation has lasted for a sufficient length of time.

Abstract: This application discloses a tube-type throttling valve assembly and the particular construction of the valve, along with the control passages and associated pilot controls.

Abstract: A control device for a fluid-operated safety valve of a boiler or the like comprises two chambers, each connected to the vessel to be protected and provided with respective valves. The first chamber is connected also to the cylinder of the safety valve via the first valve so that, when a pressure excess in the vessel develops the first chamber closes the connection between the vessel and the control cylinder while the second chamber vents the control cylinder to the atmosphere.

Abstract: The purpose of the invention is to provide a pilot-valve-controlled safety valve for venting excess pressures without allowing any noxious gas to exhaust to atmosphere in the vicinity of personnel.This purpose is achieved by the provision of a safety valve and pilot valve combination with a connection from the pilot valve to an exhaust duct of the main safety valve. Control of the exhaust rate from the pilot valve is effected by the provision of a divergent nozzle at the downstream end of the pipe leading from the pilot valve.The invention is of particular value when applied to a storage vessel for natural gas or a natural gas pipeline.

Abstract: A pilot controlled membrane valve for ventilating containers or the like comprises a valve housing having a first valve seat between the inlet and outlet of the housing. First valve means, movable between a closed position engaging said first valve seat and an open position, include a first membrane extending transversely through the housing and defining with the latter to one side of the first valve seat a valve chamber, which is connected by an overpressure passage means to the inlet. The valve includes further a pilot valve having a second seat, second valve means including a second membrane and being movable between a closed position engaging the second valve seat and an open position, a second outlet, means biasing the second valve means to the closed position and chamber means under atmospheric pressure surrounding the biasing means, in which the cross-section of the second valve seart and that of the second outlet is greater than the open cross section of the overpressure passage means.

Abstract: A safety device especially for use with a relief valve having a disk which is controlled by a pilot valve. The safety device is connected between the pilot valve and the relief valve and provides means for closing the relief valve if the pilot valve should fail. The safety device includes a body mounted between the pilot valve and the disk of the relief valve. A spring biased cage mounted inside the body is kept in a locked position away from the disk until the pilot valve fails. Upon failure of the pilot valve the cage is unlocked and the spring presses the cage against the disk to close the relief valve.

Abstract: In a nuclear reactor installation, a live-steam line leading from each steam generator through the containment, is equipped with a fast-acting valve. If the pressure in the generator rises the valve operates as a safety valve and releases up to one-half of the aperture cross section of the valve, so that there is no danger of damage to the steam generators. According to the invention, the valve is operated for this purpose by two pistons by means of steam. The invention is of interest particularly for light-water reactors, e.g., pressurized-water reactors.

Abstract: A pressure surge relief system including a valve which is opened to relieve the pipeline when line pressure overcomes a pilot chamber pressure. A pilot load duct with a variable orifice device therein connects the chamber to the pipeline. In the event of a surge, the orifice retards pressure build-up in the chamber so that it will be overcome by higher pressure in the pipeline. Pressure responsive means makes the orifice device more restrictive as pressure increases to produce a pressure lag at the control chamber even at lower velocities.

Abstract: In a pressure surge relief system wherein a valve opens to relieve the pipeline when line pressure overcomes a pilot chamber gas pressure and including an accumulator which transfers the pressure of the pipeline liquid to the gas in the pilot chamber, the improvement comprising a column of relatively inert fluid which isolates the elastomer components of the accumulator from the possibly corrosive pipeline fluid.