Abstract: A fluid tank comprising can include an outer housing comprising a housing volume, a first fluid bladder positioned within the housing volume, and a second fluid bladder positioned within the housing volume. The first fluid bladder can comprise a first conduit and the second fluid bladder can comprise a second conduit. The first fluid bladder can be configured to release fluid through the first conduit in response to introduction of fluid into the second fluid bladder via the second conduit. The housing volume can be maintained at a substantially constant pressure when fluid is released from the first fluid bladder through the first conduit and fluid is introduced into the second fluid bladder through the second conduit.

Abstract: Provided herein are liquid polymer (LP) compositions comprising a synthetic (co)polymer (e.g., an acrylamide (co)polymer), as well as methods for preparing aqueous polymer solutions by combining these LP compositions with an aqueous fluid. The resulting aqueous polymer solutions can have a concentration of a synthetic (co)polymer (e.g., an acrylamide (co)polymer) of from 50 to 15,000 ppm, and a filter ratio of 1.5 or less at 15 psi using a 1.2 ?m filter. Also provided are methods of using these aqueous polymer solutions in oil and gas operations, including enhanced oil recovery.

Abstract: Provided herein are liquid polymer (LP) compositions comprising a synthetic (co)polymer (e.g., an acrylamide (co)polymer), as well as methods for preparing aqueous polymer solutions by combining these LP compositions with an aqueous fluid. The resulting aqueous polymer solutions can have a concentration of a synthetic (co)polymer (e.g., an acrylamide (co)polymer) of from 50 to 15,000 ppm, and a filter ratio of 1.5 or less at 15 psi using a 1.2 ?m filter. Also provided are methods of using these aqueous polymer solutions in oil and gas operations, including enhanced oil recovery.

Abstract: A hand air pump with air accumulation function includes a control valve with a valve block and a control lever switchable between a first operation mode where the plunger assembly is allowed to pump compressed air into an air accumulation tank for accumulation, and a second operation mode where the air accumulation tank is opened to discharge the accumulated compressed air for inflating an attached tire and the plunger assembly is allowed to pump compressed air directly into the attached tire.

Abstract: The present invention relates to apparatus for retroperfusion of tissues and organs. The apparatus comprises a catheter with a proximal end for engaging a supply of the fluid medium, and a distal end having an expandable-contractible chamber for installation into suitable vessels or organs. The expandable-contractible chamber comprises a conduit element having a fluid-filled hollow wall defining a lumen. The conduit element has a first deformable inner-facing section approximate a proximal end of the conduit and a second deformable inner-facing section approximate a distal end of the conduit element. Controlled application of a pressure at a proximal end of the conduit element causes deformation of the conduit into the lumen at its distal end thereby occluding the flow of fluid medium through the catheter. Controlled release of the pressure releases deformation of the fluid-filled conduit at its distal end thereby unblocking the flow of the fluid medium through the catheter.

Abstract: A fuel system valve assembly may include a housing, a spring, and a body. The housing may have a fuel passage defined in part or more by a fuel passage wall. The fuel passage wall may have a seat and a cylindrical section. The cylindrical section may have a constant diameter and may be located downstream of the seat. In use, the body may reciprocate linearly in the housing between an open position and a closed position. The body may be biased to the closed position by the spring. The body may abut the seat when the body is in the closed position.

Abstract: A check valve (100) has a valve seat (20), and a valve disc (30) which closes the valve seat (20) in an openable/closable manner by linear reciprocating oscillation in the direction approaching or departing away from the valve seat (20), the check valve (100) being configured, as a lift-type check valve, to allow therein the inflow direction (D1) of a fluid (F) flowing into the valve seat (20) and the passing direction (D2) of the fluid (F) passing through the valve disc (30) to cross each other, the valve disc (30) being provided with, on the inflow side (primary side) thereof, a deflection surface (40) on which the fluid (F) is deflected from the inflow direction (D1) to the passing direction (D2).

Abstract: In a fluid control device, a check valve includes a first valve housing and a first diaphragm. The first diaphragm defines a first valve chamber and a second valve chamber. An exhaust valve includes a second valve housing and a second diaphragm. The second diaphragm defines a third valve chamber and a fourth valve chamber. The check valve is opened and closed by a difference in pressure between the first valve chamber and the second valve chamber. The exhaust valve is opened and closed by a difference in pressure between the third valve chamber and the fourth valve chamber.

Abstract: A valve housing receives a spool and the spool has a regulating chamber selectively communicating a supply line to a return line. The spool is biased in one direction by a spring force and there is a second force biasing the spool in an opposed direction with the second bias force being provided by a fluid pressure within a hydraulic system associated with the pressure regulating valve. The amount of communication between the supply port and the return port is regulated by a position of the spool as the bias force from the fluid pressure change. Damper chambers are provided on opposed sides of the spool and serve to dampen a speed of movement of the spool and a supply line for supplying fluid into the damper chambers through check valves. The supply line serves to assist in purging air outwardly of the damper chambers.

Abstract: A fluid pressure regulating system includes an auxiliary fluid circuit having a high pressure region and a low pressure region, a pump connected to the auxiliary fluid circuit and configured to discharge fluid into the high pressure region of the auxiliary fluid circuit, and a check valve connecting the high pressure region of the auxiliary fluid circuit to a main fluid interface line. The fluid pressure regulating system also includes a pressure regulating valve connecting the high pressure region of the auxiliary fluid circuit and the low pressure region of the auxiliary fluid circuit. The pressure regulating valve includes an aperture defining a fluid path from the high pressure region of the auxiliary fluid circuit to the low pressure region of the auxiliary fluid circuit. The aperture has a variable area as a function of fluid pressure within the main fluid interface line.

Abstract: The invention discloses an adaptor (10,50) for an air compressor (11,51). Adaptor (10,50) includes a manifold (14,52) having an inlet (20,74) adapted to be connected to the air exhaust of at least one air tool device (34) having an air motor connected, in use, to the air compressor (11, 51). An outlet (12,54) is adapted to be connected, in use, to the air intake of the air compressor (11,51), an air inlet (16,70) is open to ambient air and a valve mechanism (33,66) is adapted to, in use, close the air inlet (16,70) when a first predetermined pressure is reached by the air compressor (11,51).

Abstract: A high-pressure constant flow rate pump transfers a solvent from a low-pressure side liquid transfer system even if a difference between mixing ratios is large when solvents are mixed during high-pressure gradient liquid transfer. A pressure detection value from a second pressure sensor and a pressure detection value from a fourth pressure sensor are compared with each other. If the pressure detection value PA1 of the second pressure sensor is equal to or greater than the pressure detection value PA2 of the fourth pressure sensor, a second check valve comes into an opened state and operation is ended. If PA1 is less PA2, leakage determination is implemented. If it is determined that no leakage occurs, the type of the solvent is identified. A compression distance of a second plunger which is determined for each solvent and stored in a memory is added and the first plunger is driven.

Abstract: A piston has a closure face closing off a cavity defined radially inwardly and downstream of an upstream end. The closure face is spaced from the upstream end by a first distance. The piston has a cavity extending in a downstream direction away from an opposed side of the closure face to a second end. A piston diameter is defined to an outer periphery of a cylindrical portion forming a seal face. A ratio of the piston diameter to the first distance is between 3.05 and 6.31. A valve sleeve has windows formed to allow flow of fluid from a sleeve internal bore through the windows and to a downstream port. A ratio of the inner diameter to the axial dimension of the windows is between 0.91 and 1.02. A ratio of the inner diameter to a circumferential dimension of the windows is between 1.55 and 1.85.

Abstract: The disclosure relates to a micropump having a first body portion including an inlet aperture and a second body portion including an outlet aperture. The first and second body portions may each have a mating surface disposed about a membrane-receiving inner surface in sealed relation with one another. A substantially dome shaped membrane having a reinforcement annulus located around an outer edge may be received by the first body portion membrane-receiving inner surface. A portion of the membrane may be moveable between a closed position in sealable communication with the inlet aperture and an open position spaced apart from the inlet aperture, and biased in a closed position. Operation of the micropump may cause fluid to flow through the first body inlet aperture, move the membrane to the open position, and flow around the edge of the membrane through the second body outlet.

Abstract: An analyzer includes, as a cleaning system, a cleanser tank that contains a cleanser; a cleaning-water tank that contains cleaning water; a connection pipe that connects the cleanser tank with the cleaning-water tank; a pump that is provided to the connection pipe and pumps the cleanser out of the cleanser tank to the cleaning-water tank; a valve that is provided to the connection pipe and adjusts a flow of the cleanser from the cleanser tank into the cleaning-water tank; and a control unit that opens the valve and causes the pump to pump the cleanser out of the cleanser tank to the cleaning-water tank via the connection pipe to clean the inside of the cleaning-water tank and the insides of cleaning-water flow-path constituents that form a flow path through which the cleaning water flows from the cleaning-water tank when the specimen is subjected to an analysis process.

Abstract: A cleaner for the inside of a water tank utilizing a siphoning action is provided, in which the interior of a water passage (24) between an upstream-side one-way valve (Vu) and a downstream-side one-way valve (Vd) is pressurized or depressurized by a pressing operation of a suction operation tool (A) provided in a bent connecting part between a main body portion (1) and a grip portion (2) of a suction pipe (P), and water-tank water of the main body portion (1) is sucked into the suction pipe (P). This enables waste material such as leftover food within water-tank water to be sucked up together with dirty water by a very simple operation.

Abstract: A hand pump includes a base having an inlet opening and an outlet opening, a manual pump disposed on the base and communicating with the inlet opening of the base, a receptacle disposed on the base and communicating with the outlet opening of the base, a casing disposed on the receptacle and having a passage coupled to the outlet opening of the base and having a channel coupled to the receptacle and having a pathway formed between the passage and the channel of the casing, and an outlet hole communicated with the channel of the casing, a valve shank is slidably engaged in the channel of the casing for selectively blocking and sealing the outlet hole of the casing.

Abstract: A self-sealing valve comprises a valve housing having a fluid conduit, a valve seat, and a retaining member, the valve housing being configured to pass fluid through the fluid conduit, and a flexible diaphragm comprising a flexible material having resiliency, wherein the retaining member and the flexible diaphragm are configured so that the retaining member retains a portion of the flexible diaphragm so as to use the resiliency of the flexible material to bias the flexible diaphragm against the valve seat to a closed position of the self-sealing valve to provide a self-seal of the fluid conduit, and to facilitate movement of the flexible diaphragm under a fluid bias against a first side of the flexible diaphragm in a first direction away from the valve seat to an open position, and wherein the retaining member and the flexible diaphragm are configured so that the self-sealing valve can be contacted to move a portion of the flexible diaphragm away from the valve seat to the open position.

Abstract: A nuclear plant is provided with a pipe-passivating alkali-injecting device including an alkali-injecting tank, an actuator, a counter-balance valve, a pressure gauge, exhaust valves and switching valves. The actuator is connected to the alkali-injecting tank via a first pipe. The counter-balance valve is connected to the actuator via a second pipe and connected to the alkali-injecting tank via a third pipe. The pressure gauge is provided between the actuator and the counter-balance valve and connected to the second pipe. The exhaust valves are connected to the first and second pipes, and so are the switching valves. The alkali-injecting tank, the actuator and the counter-balance valve are used together to expel gases from the pipes while injecting alkali, thus effectively avoiding feedback of liquid in the nuclear plant, transmitting pure alkali in the pipes, and reducing damage to the pipes.

Abstract: A pump control system includes a source of pressurized fluid an output valve adjustably controls the flow of pressurized fluid from the source. An output valve control is coupled to the output valve and monitors the actual state of the output valve. The control selectably adjusts the output valve in response to a first control signal. A controller is coupled to the output valve control, the controller receiving information from the output valve control corresponding to the actual state of the output valve and providing to the output valve control the first control signal, the first control signal being applied to the output valve to achieve and maintain a desired state.

Abstract: A hydraulic flow sensing apparatus is provided. The apparatus includes: a manifold; a hole in the manifold in fluid communication with a fluid pathway; a poppet valve in the hole in the manifold configured to move when fluid in the pathway flows; and a proximity switch configured to detect movement of the poppet valve. A method of operating a hydraulic circuit may also be provided.

Abstract: A wheel loader (1) has a tire (5). The wheel loader (1) includes a hydraulic pump (11), a hydraulic oil tank (7) disposed at a position higher than the hydraulic pump (11) and connected to the hydraulic pump (11), a check valve (12) disposed at a position lower than the hydraulic oil tank (7) and connected to the hydraulic oil tank (7), a filter (13) disposed at a position lower than an upper surface (US) of the tire (5) in a side view and connected to the check valve (12), and a pipe (14) extending to a first position (H1) lower than the check valve (12) and further extending from the first position (H1) to a second position (H2) as a higher position than the check value (12) is set as the second position (H2), and connected to the filter (13) at the second position (H2). Accordingly, it is possible to provide a work vehicle capable of inhibiting a hydraulic oil from spilling out in exchanging the filter (13).

Abstract: A pressure control valve for reactive adhesives includes a valve housing with a liquid recirculation passage communicating with a conduit leading to a dispensing apparatus and an adhesive pump, a valve element mounted within the valve housing, and a biasing member for biasing the valve element towards a valve seat in the liquid passage. The pressure control valve also includes a flexible seal with a first end fixedly coupled to the valve element and a second end fixedly coupled to the valve housing. The flexible seal also includes an intermediate portion that flexes or deforms as the first end of the flexible seal follows movements of the valve element, thereby preventing liquid adhesive in the liquid recirculation passage from contacting the biasing member. The flexible seal may include an arch-shaped compression seal or a thin flexible annular membrane.

Abstract: A system for recirculating a vented fuel to a fuel delivery system of a gas turbine generally includes a vented fuel conduit in fluid communication with the fuel delivery system and a container in fluid communication with the vented fuel conduit. A pump is disposed downstream from the container and a fuel conduit is disposed downstream from the pump. The fuel conduit may provide fluid communication from the pump to the fuel delivery system.

Abstract: Systems for removing water from an area where water is not desired are discussed and provided. The system can include a dam, a water collection system, and a water removal system. The dam can create a waterproof seal so that the dam is configured to define a reservoir, or retention area, capable of holding water. The water collection system can remove substantially all of the water that collects in the retention area and deposit the water in a reservoir when the water collection system is triggered by a first sensor. The water removal system can move the water collected in the reservoir to an area of safe disposal through a hose or drain when triggered by a second sensor. Other aspects, features, and embodiments of the present invention are claimed and described.

Abstract: A hydraulic control arrangement includes a common variable displacement pump configured to supply pressure medium to two consumer groups. The pressure level of a control block assigned to one of the consumer groups is set to a different pressure level than that of a further control block assigned to the other consumer group.

Abstract: A fluid control apparatus compact in size and high in performance, and a fuel supply system provided with the fluid control apparatus. The first valve opening direction in which a valve body of a relief valve is separated from a valve seat and the second valve opening direction in which a valve body of a discharge valve is separated from a valve seat are opposite to each other. The first valve opening drive pressure to have the valve body of the relief valve separated from the valve seat and the second valve opening drive pressure to have the valve body of the discharge valve separated from the valve seat are different from each other. The valve seat is provided integrally with the valve body. The fluid control apparatus is provided with a displacement limiting mechanism that limits the displacement of the valve body.

Abstract: A hydraulic system of an electric vehicle may comprise: an oil container; a first and a second clutch driving circuits connected in parallel; an internal pump driven by a driving system of the electric vehicle; a first check valve connected in series at an outlet side of the internal pump; an external pump driven by an external pump motor; and a second check valve connected in series at an outlet side of the external pump. The first check valve and the internal pump connected in series and the second check valve and the external pump connected in series are connected in parallel between the oil container and the first and second clutch driving circuits.

Abstract: A method of monitoring operation of a fuel system includes urging a fuel flow from a fuel source toward a pressure regulating valve via a fuel pump. A pressure of the fuel flow is detected at the pressure regulating valve, and a pump speed required to produce a selected pressure at the pressure regulating valve is detected. The pump speed is compared to a range of acceptable pump speeds, and an operational status of the fuel pump is determined based on a result of the comparison.

Abstract: An inflatable product has an air pump device and a pressure releasing valve. The air pump device has a housing and a pumping assembly. The housing has two openings as an inlet opening and an outlet opening. The pumping assembly is mounted in the housing and has a motor and a fan. The motor is mounted between the inlet and outlet openings and drives the fan. Consequently, mounting the motor between the first opening and the second opening dissipates the heat of the motor because the air passing by the motor cools the motor. The pressure releasing valve is adjusted by users and releases air while pressure of air in the inflatable body reaches a predetermined pressure level.

Abstract: The present invention relates to a decompression module using a gas stream and a vacuum apparatus for manufacturing a semiconductor device, in which the venturi effect due to a carrier gas stream is used to decompress an exhaust-side pressure of a vacuum pump without requiring an additional power, thereby being capable of appropriately reducing the load of the vacuum pump and the power consumption.

Abstract: An aircraft fuel system is provided and includes a metering valve having inlet and outlet sides to monitor fuel flow from the inlet to the outlet side, a check valve that, when opened, allows fuel to flow toward the inlet side during start and climb conditions and, when closed, prevents such fuel flow and an ejector pump, which is operably disposed between the check valve and the metering valve, and which, with the check valve closed, pumps fuel toward the inlet side during idle conditions.

Abstract: An energy production and pressurized exhaust gas storage system including two combustion chambers aligned in opposition to each other, each of the two combustion chambers having a reciprocating power piston. A compression chamber is situated between the two combustion chambers and it includes a reciprocating compression piston. A shaft connects all of the pistons together. A solvent tank is connected to the two combustion chambers to receive the exhaust gas carbon dioxide. The solvent is preferably water maintained at about 32 degrees Fahrenheit and with a pressure above the water surface of about 100 pounds per square inch. Upon combustion, a pressurized carbon dioxide storage chamber receives compressed carbon dioxide from the compression chamber. Check valves are used to enable inflow of carbon dioxide to the compression chamber from the solvent tank and outflow of pressurized carbon dioxide in the compression chamber to storage.

Abstract: This invention provides a positive displacement gas operated pump and pumping system for pumping fluids such as hydrocarbons/oil as well as solids that may be suspended in such fluids. More specifically, the invention relates to a method and apparatus for the recovery of hydrocarbons/oil from underground water tables and/or where water flooding has previously been used to further extract hydrocarbons/oil from underground areas, but economics prevent further recovery from such areas and/or wells.

Abstract: Apparatus for introducing air (3) into a hydropneumatic reservoir (1) connected to pipework (2) comprising a sensor (6) of the pressure in the reservoir, a valve (9) controlled by a signal from the sensor and opening into the open air on one side, a tube (8) connected at one end to the valve and at the opposite end to the pipework (2), a first check valve (11) arranged in the tube to prevent liquid from travelling towards the open air, and a second check valve (5) arranged in the pipework between the reservoir (1) and the tube (8), the second check valve (5) being in the closed state when the pressure in the pipework (2) on the side nearest the tube (8) is less than the pressure in the reservoir (1).

Abstract: Disclosed is a fuel conveying device including a valve housing in which a pressure release valve and a non-return valve are arranged parallel to one another, the pressure release valve having a first inlet, which downstream of a valve seat opens into a valve chamber in which a valve body is movably arranged and which is in fluid connection with a second inlet for the non-return valve via a first outlet. The device improves the control response of the pressure release valve by providing the first outlet at the periphery of the valve chamber and in the axial direction with respect to a valve axis such that when the pressure release valve is open the flow from the valve chamber into the second inlet is a substantially radial flow.

Abstract: An arrangement for the hydraulic adjustment of the propeller blades of an aircraft propeller (1) with the help of a hydraulic pump (5) having a hydraulic cylinder (3) which is acted upon by compressed oil comprises a pressure control valve (11) arranged parallel to the hydraulic pump and connected directly to the pressure connection (4) and intake connection (8) thereof, preferably integrated into the pump housing (14). The pump losses and heating of the oil are therefore reduced and hydraulic efficiency is improved.

Abstract: A device including a first discharge passage from a first rotor assembly to an engine, a first return passage that returns to an intake side of the first rotor assembly, a second discharge passage from a second rotor assembly to the engine, a second return passage that returns to an intake side of the second rotor assembly, and a pressure control valve whose valve main body is provided between a discharge port from the second rotor assembly and the first discharge passage. The first discharge passage and the second discharge passage are coupled, and a flow passage control is executed in each of: a low revolution range; an intermediate revolution range; and a high revolution range.

Abstract: An oil circulating control system for an engine includes an engine speed module and a mode selection module. The engine speed module determines a speed of the engine. The mode selection module is configured to select a first pressure mode and a second pressure mode of an oil pump of the engine for the speed. The selection module selects one of the first pressure mode and the second pressure mode based on at least one mode request signal. The mode selection module signals a solenoid valve of a variable oil pressure circuit of the oil pump to transition to a first position when operating in the first pressure mode and to a second position when operating in the second pressure mode.

Abstract: A bi-directional pressurized system with devices for and configured to mitigate issues associated with leak and creep phenomena at various stages throughout the system, including valves and controls to distribute a leaked amount of fluid prior to delivery to a pressure-sensitive destination and a pressure relief valve to bring an initial pressure within an acceptable range for distribution to reach a target pressure. A startup method for mitigating leakage of the system during a rest phase, including selectively reducing the initial pressure upstream of a pressure-sensitive destination.

Abstract: A control device for an industrial vehicle including an electric storage device, a load device, a hydraulic pump, and a load motor is disclosed. The electric storage device stores regenerative power generated through regenerative braking performed by the travel motor. The hydraulic pump supplies a hydraulic circuit with hydraulic oil to operate the load device. The load motor drives the hydraulic pump. The control device includes a power control unit and a resistance flow passage. The power control unit executes control for supplying the load motor with the regenerative power when the electric storage device is in a fully charged state during regenerative braking performed by the travel motor. The resistance flow passage is arranged in the hydraulic circuit and enables passage of hydraulic oil while applying flow resistance to the hydraulic oil.

Abstract: A fluid distribution system for a machine tool is disclosed. The system includes a return and a filter in fluid communication with the return. A heat exchanger is in fluid communication with the filter. A pump is in fluid communication with the heat exchanger and a drive motor drives the pump. A valve is in fluid communication with the pump and a fluid distribution outlet. A controller is operatively connected to the drive motor and the valve.

Abstract: Apparatus for introducing air (3) into a hydropneumatic reservoir (1) connected to pipework (2) comprising a sensor (6) of the pressure in the reservoir, a valve (9) controlled by a signal from the sensor and opening into the open air on one side, a tube (8) connected at one end to the valve and at the opposite end to the pipework (2), a first check valve (11) arranged in the tube to prevent liquid from travelling towards the open air, and a second check valve (5) arranged in the pipework between the reservoir (1) and the tube (8), the second check valve (5) being in the closed state when the pressure in the pipework (2) on the side nearest the tube (8) is less than the pressure in the reservoir (1).

Abstract: A parts assembly includes a housing including a first part assembly hole on which a first apparatus component is assembled, the first apparatus component being fixed to the housing by means of a caulking for forming a caulking portion by a deformation of a bearing surface of the housing on which the first apparatus component is seated. The housing includes a second part assembly hole provided in the vicinity of the caulking portion and on which a second apparatus component is assembled. The housing includes a sacrificial deformation portion deformed by a force applied to the housing when the bearing surface is deformed by means of the caulking, the sacrificial deformation portion attenuating a force propagated to a portion including the second part assembly hole where the second apparatus component is assembled.

Abstract: A system for pressurizing and exhausting a vented chamber is disclosed. The present disclosure includes a unitary module having two integrated valves for each supported chamber, a single inlet port for each chamber, a single vent exhaust port and a single pressurized port. In addition, a number of pressure gauge ports are provided to allow the pressure at various points to be monitored. In addition, the unitary module optionally includes a leak check port. Using this port, the operator can test the integrity of all valves within the module.

Abstract: Systems and methods are provided for hydrogen generation utilizing two or more liquid fuel components, using a fuel delivery system comprising a single reversible or bi-directional pump co-operable with flow control means comprising passive or active valves to deliver two or more fuel components to a mixing zone, reaction zone, or reaction chamber of a hydrogen generation system. The pump is operable in a forward direction to deliver one fuel component, and in a reverse direction to deliver a second fuel component. Control of the pump speed, direction and duty cycle of the pump in continuous or pulsed modes provides for delivery of first and second fuel components in desired proportions, to control hydrogen generation. The system also allows for dilution, mixing and flush cycles to be provided using a single pump, reducing the number of active elements required for fuel delivery and flow control in systems using two or more liquid fuel components.

Abstract: A first tank, a main body of a compressor, an electric motor, and a second tank are combined to form a single assembly. A booster type air compressor as the single assembly including the first tank may be easily carried. The first tank at an inlet side is integrally combined to prevent a pulsation in the supplied compressed air for eliminating the drain contained in the compressed air. The air compressor, thus, is structured to discharge high compressed air from a high-pressure outlet joint formed on the second tank.

Abstract: A two-stage system for delivering fuel to a gas turbine including a first stage variable pump for serving as a primary source of fuel, a second stage fixed pump for selectively supplementing the variable pump, a bypass valve connected to the fixed pump for loading and unloading the fixed pump and a regulator valve assembly connected to the variable pump and the bypass valve for controlling operation of the variable pump and the bypass valve. Preferably, the two-stage system also includes a control valve connected to the regulator valve assembly for setting a pressure differential across the regulator valve assembly and, thereby, loading and unloading the fixed pump.

Abstract: A device for reducing friction while maintaining characteristics identical to the pressure characteristics of a common oil pump based on provision of a plurality of discharge sources and a newly devised method of switching oil passages. The device is configured from a first discharge passage from a first rotor assembly to an engine, a first return passage that returns to an intake side of the first rotor assembly, a second discharge passage from a second rotor assembly to the engine, a second return passage that returns to an intake side of the second rotor assembly, and a pressure control valve whose valve main body is provided between a discharge port from the second rotor assembly and the first discharge passage.

Abstract: A hydraulic system includes a charge pump which supplies fluid to variable displacement main pump, a fluid reservoir and valve unit. The valve unit includes a hollow housing having a first end communicated with the reservoir and a second end communicated with the charge pump and the main pump. A housing valve land member is located between the first and second ends. A valve member is movably mounted in the housing. The valve member has a valve disk attached to first and second valve stems which project from opposite sides of the valve disk. The valve disk has a central position wherein the valve disk is received by the ring. The valve stems are slidably supported by stem support members at opposite ends of the housing. A hollow sleeve projects from an end of the valve unit. A spring is mounted in the sleeve and is engagable with an end of one of the valve stems and is biased to urge the valve member away from the sleeve.