Abstract: A magnetically driven micropump for handling small fluid volumes. The micropump includes a first chamber and a second chamber. A flexible membrane being disposed between the first and second chambers. The flexible membrane being magnetically coupled to an actuator for displacing the membrane.

Abstract: Peristaltic pump assemblies in which the closing and opening of a pivoting or sliding door is coordinated with movement of the occlusion bed toward and away from the rotor assembly to engage and disengage tubing within the occlusion pathway are disclosed. Linkage mechanisms provided by the interaction of cam surfaces with rollers, as well as bar linkage mechanisms, are disclosed. The linkage mechanism, in addition to providing precise displacement of the occlusion bed, may also provide an over-center feature that enhances safety and pump operation when the door is in a closed position. Latching mechanisms and sensors may be incorporated. Adaptive components such as tubing cassettes routing aspiration and/or infusion tubing in a predetermined configuration to mate with occlusion pathways in aspiration and/or infusion pump assemblies provided in various types of medical devices and control consoles are also provided.

Abstract: An apparatus is provided and may include a control valve that moves a pressure-responsive unloader valve between a first position permitting flow through a valve plate and into a compression mechanism and a second position restricting flow through the valve plate and into the compression mechanism. The control valve may include at least one pressure-responsive valve member movable between a first state supplying discharge-pressure gas to the unloader valve to urge the unloader valve into one of the first position and the second position and a second state venting the discharge-pressure gas from the unloader valve to move the unloader valve into the other of the first position and the second position.

Abstract: A method and apparatus for blowing down a compressed air system when temperature is at or below a predefined temperature threshold is provided. Temperature sensors in the compressed air system monitor temperature and a control processor determines when the temperature is at or below the predefined temperature threshold. When it is determined temperature is at or below the predefined temperature threshold, the control processor operates a solenoid blow-down valve that depressurizes the compressed air system.

Abstract: A common regulator valve is provided for a variable displacement pump fuel metering scheme in which the common regulator valve both controls working output to a pump actuator to control displacement of the variable displacement pump and also to control bypass of excess fuel flow. The regulator valve also includes a differential piston which generates a compensation force off of the bypass flow in order to compensate for changes in spring force and flow reaction force at different system pressures and operational states. As a result, errors in the metered fuel flow can be either eliminated or substantially reduced.

Abstract: A closing element is for a valve assembly of a compressor unloader, the compressor including a casing with a compression chamber, the unloader including a housing defining a chamber. The valve assembly has a base between the compression and unloader chambers, a passage connecting the two chambers, a seat about the passage, and a stem bore within the base having a control chamber. The closing element includes a main body movably disposed within the stem bore and having a sealing surface disposeable against the valve seating surface to obstruct the valve passage and a control end surface within the bore control chamber A sealing member disposed about the main body prevents flow between the control chamber and the valve passage. The main body and/or the sealing member is configured such that the main body is radially moveable to align the body sealing surface with the valve seat.

Abstract: A compressor arrangement includes a compressor housing, an intake region defined in the compressor housing, a control pressure connection in communication with the intake region, a control pressure chamber in communication with the control pressure connection, a control piston disposed in the compressor housing beneath the control pressure chamber, a guide element securing the control piston in the compressor housing, at least one sealing element disposed between the control piston and the guide element, and a feed pressure connection defined in the compressor housing to supply compressed air beneath the control piston. In a closed position, the control piston closes the feed pressure connection when in the closed position. In an opened position, the control piston opens the feed pressure connection when in the opened position, thereby permitting air to vent from the feed pressure connection via a venting connection.

Abstract: A drain protection device and pump controller for pools, spas, fountains and other fluid containment and circulation systems has a vacuum sensor for sensing a level of vacuum present in the suction conduit leading to the pump(s). The vacuum level is monitored by a computer that controls a vent valve that can vent to atmosphere to reduce the vacuum exerted at a drain. In applications with a flooded pump, e.g., above-ground pools, the vent valve may control the discharge of an accumulator that injects fluid pressurized by the return line into the suction conduit to reduce the vacuum therein. The computer also controls the pump(s) present in the circulation system, viz., turns them off to relieve vacuum when a drain is occluded and also runs them at the selected speed based upon a schedule. The vacuum criteria for vacuum reduction may include progressively sensitive values, some of which may be empirically based. Vacuum criteria may be maintained based upon the operational state of the circulation system, e.g.

Abstract: A vacuum relief safety valve includes a housing defining an inner chamber and attached to the suction-side of the swimming pool or spa pump. An air inlet aperture is formed in the housing so as to be open to ambient air. A sealing element is disposed within the housing and biased against the air inlet aperture by a spring so as to effectively seal the inner chamber of the housing from ambient air. When a maximum allowed vacuum level within the pump is exceeded, such as when a swimming pool drain is obstructed, the sealing element moves into the inner chamber and opens the air inlet aperture causing the pump to rapidly lose its prime and enabling removal of the entrapment. Simultaneously, the movement of the sealing element provides electricity to a control circuit which shuts off power to the pump.

Abstract: A fluid metering device for monitoring flow of fluid is provided. The fluid metering device comprises: an electric motor; and a housing having a manifold section, a motor adapter plate and a pressure retaining container, said pressure retaining container encompassing a pressurized chamber having a hydraulic pump placed in the pressurized chamber; and the manifold section including an air bleed valve and a pressure biased relief valve for maintaining pressure within the housing.

Abstract: Pump for applying an increased or reduced pressure to a container. The pump is provided with a plate-like part which reacts to the pressure difference between the container and the environment. This part can preferably adopt two stable positions, and a change is signalled. This change can be brought about, for example, by the sound generated as a result of the plate-like part turning over. The pitch and the like of the sound can be influenced by arranging the plate-like part in a hollow piston and providing the latter with openings leading to the environment.

Abstract: A vacuum relief safety valve includes a housing defining an inner chamber and attached to the suction-side of the swimming pool or spa pump. An air inlet aperture is formed in the housing so as to be open to ambient air. A sealing element is disposed within the housing and biased against the air inlet aperture by a spring so as to effectively seal the inner chamber of the housing from ambient air. When a maximum allowed vacuum level within the pump is exceeded, such as when a swimming pool drain is obstructed, the sealing element moves into the inner chamber and opens the air inlet aperture causing the pump to rapidly lose its prime and enabling removal of the entrapment.

Abstract: A method and system is provided for reducing chatter in multi-capacity compressors having disengageable eccentric structures. The multi-capacity fluid compressor includes a compression chamber having a discharge end and an inner surface. The compressor also includes a compression member having a disengageable eccentric structure allowing the compressor to provide discrete compression capacities. A valve portion is disposed adjacent to the discharge end of the compression chamber and is arranged and disposed to discharge a compressed fluid when the compression member has completed. A discharge arrangement is arranged and disposed to discharge at least a portion of fluid remaining in the compression chamber at the completion of the compression cycle. The discharge of at least a portion of the fluid remaining in the compression chamber reduces or eliminates forces on the disengageable eccentric structure to limit rotational acceleration of the disengageable eccentric structure.

Abstract: A drain protection device and pump controller for pools, spas, fountains and other fluid containment and circulation systems has a vacuum sensor for sensing a level of vacuum present in the suction conduit leading to the pump(s). The vacuum level is monitored by a computer that controls a vent valve that can vent to atmosphere to reduce the vacuum exerted at a drain. In applications with a flooded pump, e.g., above-ground pools, the vent valve may control the discharge of an accumulator that injects fluid pressurized by the return line into the suction conduit to reduce the vacuum therein. The computer also controls the pump(s) present in the circulation system, viz., turns them off to relieve vacuum when a drain is occluded and also runs them at the selected speed based upon a schedule. The vacuum criteria for vacuum reduction may include progressively sensitive values, some of which may be empirically based. Vacuum criteria may be maintained based upon the operational state of the circulation system, e.g.

Abstract: A liquid delivery system includes a first reservoir having a first outlet through which liquid is delivered. A first delivery outlet is located at the lower portion of the first reservoir and a vent is included at its upper portion. A second reservoir located above the first reservoir and has a second outlet located in its lower portion. A first delivery conduit connects the second outlet to the first reservoir and a second delivery conduit connects the upper portion of the first reservoir with the upper portion of the interior of the second reservoir. A vent valve controls communication through the second delivery conduit. A level sensor senses the level of liquid in the first reservoir and causes the vent valve to open when the liquid falls below a first predetermined level and to close the vent valve when on the level rises above a second (higher) predetermined level.

Abstract: An apparatus for removing oil from air in an air compressor that has a piston reciprocable in a cylinder to compress the air, includes an oil removal chamber associated with the compressor. An unloader valve has an unactuated condition and an actuated condition disabling flow of compressed air out of the compressor and establishing fluid communication between the cylinder and the oil removal chamber. The apparatus may include an oil discharge port for draining oil from the oil removal chamber to a location away from the cylinder, and/or a filter element in the oil removal chamber.

Abstract: In a dipping type pump where a rotary shaft extending from a motor into a pump casing disposed in liquid is mounted with impellers, and liquid is sucked from a sucking port at a lower portion of the casing and discharged from a discharge port by rotational driving of the motor, where a check valve for air purge which allows outflow of gas from the interior of the casing but prevents outflow of liquid therefrom is provided at an upper portion of the casing.

Abstract: A liquid chemical metering pump (24) is described that can be fully submerged within a hazardous liquid chemical transport/storage container (28). The pump (24) includes a discharge adaptor (30) that can be received in the outlet aperture (40) of the container (28), in which it is held in sealing relationship by a suitable screw-threaded connector. The discharge adaptor (30) is provided with an intake port (32) in fluid communication with the liquid chemical in the container (28), and a discharge port (34) which is in fluid communication with a discharge tube (36) leading to a flow stream (38). The chemical metering pump (24) is remotely controlled by an electronic controller (26) connected by cable (25) to the chemical metering pump. The chemical metering pump (24) substantially eliminates the need for “double handling” of hazardous liquid chemical, as the chemical can be metered directly from the transport/storage containers in which it is delivered to the end user.

Abstract: Disclosed is a vacuum preventing device for a scroll compressor comprising: a housing fixed to an upper surface of a fixed scroll to cover a compression hole and a suction hole and having a discharge hole at an upper surface thereof and a rotation member receiving space therein; and a rotation member fixed to a shaft of the receiving space so as to rotate by a pressure difference of gas introduced through the compression hole and the discharge hole and having a compression gas receiving groove for opening/closing the compression hole at one side thereof and a suction gas receiving groove for opening/closing the suction hole and the discharge hole at the other side thereof.

Abstract: An unloader system is provided for a reciprocating gas compressor. The system includes an unloader valve assembly including a valve member controlling flow between compressor cylinder and a clearance bottle. Opening and closing of the valve member is controlled by manipulating a control pressure acting through a manifold against the stem of the valve member by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: Disclosed is a vacuum preventing device for a scroll compressor comprising: a housing fixed to an upper surface of a fixed scroll to cover a compression hole and a suction hole and having a discharge hole at an upper surface thereof and a rotation member receiving space therein; and a rotation member fixed to a shaft of the receiving space so as to rotate by a pressure difference of gas introduced through the compression hole and the discharge hole and having a compression gas receiving groove for opening/closing the compression hole at one side thereof and a suction gas receiving groove for opening/closing the suction hole and the discharge hole at the other side thereof.

Abstract: A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects to the fluid transfer/circulation system and includes a sensor, a triggering mechanism, and a vacuum breaker. When the pump is operating, the sensor monitors one or more conditions of the system. When one or more of the monitored conditions deviates outside of a normal operational range, as a result of an obstruction of any one or more of the open ends of the intake lines, the triggering mechanism triggers the vacuum breaker to eliminate negative pressure in the system by introducing air from atmosphere into the intake lines, thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated.

Abstract: An unloader system is provided for a reciprocating gas compressor. The system includes an unloader valve assembly including a valve member controlling flow between compressor cylinder and a clearance bottle. Opening and closing of the valve member is controlled by manipulating a control pressure acting through a manifold against the stem of the valve member by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects to the fluid transfer/circulation system and includes a sensor, a triggering mechanism, and a vacuum breaker. When the pump is operating, the sensor monitors one or more conditions of the system. When one or more of the monitored conditions deviates outside of a normal operational range, as a result of an obstruction of any one or more of the open ends of the intake lines, the triggering mechanism triggers the vacuum breaker to eliminate negative pressure in the system by introducing air from atmosphere into the intake lines, thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated.

Abstract: A safety device for use in a fluid transfer and/or circulation system of the type which uses a pump to draw water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The safety device connects in-line with the fluid transfer/circulation system, between the open ends of the intake lines and the pump and includes a vacuum pressure sensor, an analyzer and controller, a relay, and a vacuum breaker. Each time the pump is activated, the device analyzes negative pressure levels throughout a start-up period to establish a normal operating pressure window for the particular system.

Abstract: A variable discharge-amount compressor includes a compression unit for compressing refrigerant, and a discharge-amount varying unit for varying a discharge amount of refrigerant discharged from the compression unit. The discharge-amount varying unit has a first control room communicating with inlet and outlet of the compression unit, a second control room communicating with the inlet, and a third control room communicating with the second control room through a orifice. The first control room communicates with the inlet through a control passage opened and closed by a control valve. Further, a bypass passage communicating with the inlet is opened when the control passage is opened. Therefore, when an engine for driving the compressor is rotated to be accelerated, a pressure difference is generated between a pressure inside the second control room and a pressure inside the third control room, thereby opening the control passage and the bypass passage.

Abstract: The present invention provides a gas vent system for a vacuum chamber. The particle placed onto the wafer after loading out from a vacuum chamber can be greatly reduced by the system design. The gas vent system has a gas supply, an anti-vibrating tube, a gas regulator, a first line, a second line, a vent valve, and a filter. The anti-vibrating tube is connected after the gas supply for transferring gas without introducing vibration. The gas regulator is connected after the anti-vibrating tube for controlling a flow rate of the gas. The first line is connected after the gas regulator and has a first metering valve. The second line is connected after the gas regulator and is also connected in parallel with the first line. The second line has a second metering valve and an in-line valve in series. The vent valve is connected after the first line and the second line. The filter is connected between the vent valve and the vacuum chamber.

Abstract: A compressed air installation having a normal operating mode and an idling mode includes a feed valve, a feed line which is connected to and receives air through the feed valve, at least one compressor having at least one compression chamber, and at least one inlet valve which is connected to the feed line and supplies air to the compression chamber. The feed valve and the inlet valve are switchable between open positions and one-way positions wherein air can pass through the valve in one direction only. In normal operating mode, the feed valve is in its open position and the inlet valve is in its one-way position, thereby allowing air to enter and exit the installation through the feed valve and the feed line, and to pass from the feed line through the inlet valve into the compression chamber.

Abstract: A vacuum system, particularly for vacuum grippers, has a fluid entrainment pump for generating the vacuum which, when the required vacuum is built up, is supplied with a throttled compressed-air flow. For the throttling of the compressed-air flow, a controlled throttle device is used which, as a function of the detected vacuum value, throttles the compressed-air flow to the fluid entrainment pump when the desired vacuum value has been reached or exceeded.

Abstract: An improved vacuum apparatus and method is provided which includes a vacuum body, pump or ejector which produces a plurality of high velocity liquid jet streams of a primary fluid (liquid) such as water discharged into a convergent diffuser to draw a secondary fluid (gas) such as air into a vacuum chamber. The secondary fluid (gas) is entrained within flow spaces formed between the liquid jet streams and is carried through the diffuser by the jet streams. A secondary fluid inlet is operatively connected to an elongate hose which serves as a vacuum line for evacuating, for example, a Mason Jar, a plastic bag, other food storage container, an oil storage or receiving receptacle, or the like. The present invention is especially adapted for use as or in a vacuum seal kit or oil change kit, but not limited thereto.

Abstract: A combined compressor pressure sensor and excess pressure relief valve (12) uses a formed disk (22) that snaps down and back up at a pair of predetermined pressures. The disk (22), when it snaps down, opens a plug (34) to in turn allow excess pressure from the compressor (10) to escape. When up, the plug (34) remains sealed, the outside vents (42) remain blocked, and compressor gas flow only through the center of the plug (34) and disk (22) to a sensing chamber (46).

Abstract: A breast pump for sucking out mother's milk is provided, the breast pump including a sucking portion 11, 12, 13 to be fitted to one's breast, a negative pressure generating member 14 mounted in the sucking portion for generating negative pressures therein, a driving member 24 attached to the sucking portion, a driving power transmitting member 25 attached to the sucking portion for repeatedly generating negative pressures by transmitting a driving power of the driving member, and a reservoir 30 connected to the sucking portion for reserving mother's milk from the sucking portion.

Abstract: A safety device for use in a fluid transfer system for a swimming pool or similiar application, having a pump which draws water from a reservoir through one or more intake lines each extending from an open end at the reservoir to the pump intake. The device analyzes negative pressure levels in the system and, upon detecting a negative pressure level being outside of a selected operational range, the device deactivates the pump and triggers a vacuum breaker device to eliminate negative pressure in the system, by introducing air from atmosphere into the intake lines thereby removing suction at the open ends of the intake lines. The safety device may further activate warning devices including audible and visible alarms to indicate that the system has been deactivated.

Abstract: In a method of and a device for suction transporting a material from an object surface, the suction transporting device has a suction unit and a unit for modulating the suction. A suction is applied to a transporting line by the suction unit so that a material is transported through the transporting line from an inlet to an outlet. A suction force of the suction produced in the transporting line is modulated by communicating an interior of the transporting line with atmosphere through a passage and periodically changing the area and the shape of the passage during the transporting. The frequency of the modulation is changed in dependence on the distance between the inlet of the transporting line and the object surface.

Abstract: A safety relief valve assembly for use in a fluid displacement apparatus of an automotive air conditioning system includes a valve mechanism which releases gas when the pressure in the fluid displacement apparatus increases above a predetermined pressure level. A control device is detachably mounted on the valve mechanism to direct the flow of the gas in a predetermined direction. An elastic member is forcibly disposed between the valve mechanism and the control device. The elastic member has a groove facing the valve mechanism. The groove and the valve mechanism collectively form a passage for directing excessively pressurized gas away from the hot components in the vehicle engine compartment.

Abstract: An apparatus for vacuum absorption is provided which is quiet and simplified with maintaining an absorption power. The apparatus comprises: a tank for accumulating circulating water; a waterway for circulating the circulating water by a pump disposed at an absorption inlet side of the waterway and having an outlet disposed over the water surface of the circulating water in the tank; an aspirator disposed on the waterway; and a reverseflow prevention mechanism surrounding the outlet, having a small hole of the size to drain less volume of water than the volume flowing out of the outlet at the position sunk under the water, and comprising a buffer (hollow body) with drain windows at the position over the water surface. The apparatus serves to drain the circulating water into the water during the operation of the pump and to absorb air from the outlet into the vacuum vessel during the stoppage of the pump.

Abstract: The inventive device produces compressed gas. It is provided with a compressor, wherein the compressor has a compression chamber (25), a suction chamber (10) and a pressure chamber (6). The compression chamber (25) can be connected to the suction chamber (10) via a suction valve (12, 21, 54) and to the pressure chamber (6) via a pressure valve (3). When the receiving-end pressure reaches a predetermined level, the pressure chamber (6) is connected to a compressed-air supply container (44). This connection is via a device for the discontinuation of compressing action (23, 51). In addition, the pressure in the pressure chamber (6) is monitored by a control valve (26), which is a sensing device with a control output (38). The sensing device (26) is designed to produce a control signal at the control output (38), when the pressure in the pressure chamber (6) or compression chamber (25) of the compressor reaches or exceeds a predetermined value.

Abstract: The present invention relates to a gas compressor which prevents noise being produced in the suction conduit during idling. In conventional systems, the noise results from the collision of arriving and returning gas by means of a check valve provided between the suction chamber and the suction conduit. The present invention avoids this noise by providing an additional chamber which is connected via an admixture valve to the compression chamber (20) during the idling operation. This invention is especially applicable to pneumatic systems in automotive technology.

Abstract: A pressure relief assembly for use with a paint pump having a chamber with a pressure relief port located immediately adjacent an inlet port of the pump. The pressure relief assembly includes a mounting member, inlet washer, rupture pad and outlet washer. The mounting member is threaded on its exterior surface and includes an inlet end, an outlet end, and a relief passage extending between the inlet and outlet ends. A rupture recess in the inlet end is sized to receive the inlet washer, rupture pad and outlet washer, with the rupture pad positioned between the washers. The inner diameter surface of the outlet washer is convex. The pressure relief assembly is screwed into the pump with the inlet end adjacent to the pressure relief port. The rupture pad forms a seal between the pump chamber and atmosphere that ruptures to vent the chamber when the pressure within the chamber exceeds a predetermined rupture pressure.

Abstract: A suction transporting device for transporting a material has a suction unit, a transporting line connected with the suction unit and having an inlet for receiving a material to be transported and an outlet for discharging the material to be transported and a unit for modulating a suction force of a suction produced in the transporting line by the suction unit, the modulating unit including a passage adapted to communicate the interior of the transporting line with atmosphere, an adjusting element operative for adjusting an initial area and shape of a minimal cross-section of the passage, and a valve mechanism including a drive, a speed controller for controlling a speed of the drive, and a valve body connected with the drive and cooperating with the passage so that when the valve body is displaced by the drive, an initial area and shape of the minimal cross-section of the passage is periodically changed.

Abstract: A fuel pump includes a connecting pipe having an open end disposed at the lowest point in a pressure chamber supplied with fuel by a pressure valve. The connecting pipe is connected to a mixture-former and the pressure chamber has in its upper region a ball valve with a return line which leads to a fuel tank. The pressure chamber can have a cavity establishing the lowest region thereof, the open end of the connecting size being disposed in the cavity. A filter can surround the lower end of the pipe to filter the fuel supplied thereto.

Abstract: A diaphragm-type vacuum pump device which includes a diaphragm, a pumping chamber the volume of which is changed by reciprocating motion of the diaphragm, a check valve for drawing air into the pumping chamber, a check valve for discharging air from the pumping chamber and an orifice or relief valve disposed in the pumping chamber so that the pumping chamber communicates with atmosphere.

Abstract: Vacuum pumping system comprises a plurality of vacuum processing vessels, semiconductor processing reactors, and the like, connected to a common manifold evacuated by a generously large central vacuum unit. The manifold is maintained at a substantially constant designated pre-set pressure higher than the pressures within the reactors by means of a gas bleed inlet valve controllably feeding an inert gas into the manifold. A blower package with valving, interposed between each reactor and the common manifold, discharges directly into the manifold and prevents pressure surges and excursions in the manifold and reactors as well as permitting each reactor to operate at different pressures independently of the existing manifold pressure.

Abstract: A casing gas pump is reciprocated by the pump jack of an oil well. Push rods slidable within rigid vertical cylinders are connected by a bridle bracket to bridle cables depended from the pump jack horsehead. Vertical reciprocation of the horsehead moves pump leathers connected to the push rods up and down within cylinder bores. The cylinders are vertical, non-pivoting and fluidly connected to a header. The header is connected to the annulus of the well and to a gas line. Check valves prevent back flow from the header into the annulus and from the gas line into the header. The pump leathers form reciprocating pistons that are formed and assembled to avoid pulling a vacuum on the annulus.

Abstract: Method and device for safeguarding hydraulic transport of a suspension of edging spoil and water by supplementing a dosed water amount onto the suction side of the pump, whereas as much and as long as possible suction power is maintained in the suction duct for feeding much material to be transported and little water into the suction duct.

Abstract: A back-flow prevention valve assembly is disclosed for use with a vacuum pump or the like and employs a valve element movable between positions opening or closing a passageway through the assembly. In the event of pump failure, a control valve, which is operated by fluid from the pressure side of the pump, vents ambient air behind the valve element to assist it in moving rapidly to the closed position to prevent backflow. After resumption of pumping, a controlled withdrawal of ambient air behind the valve element delays opening of the valve until the pump has created a sufficient vacuum to minimize influx of air upstream when the valve opens.

Abstract: For gear boxes, constant speed drives and the like having an airtight housing, a self-pressurization system includes a source of liquid, a pump having a discharge port connected to the housing, a check valve in a conduit extending between atmosphere and the pump intake port, and a valve responsive to the pressure differential between the housing and atmosphere and connected between the source of liquid and the pump intake port to deliver large amounts of liquid to the pump when the pressure differential is high and to deliver air and minimal lubricating amounts of liquid when the pressure differential is low.

Abstract: Air flow control system comprising a pump having an air pressure outlet and a vacuum outlet; an air utilization device such as a desolderer; and a multi-position switch having first and second input ports respectively connected to the air pressure and vacuum outlets of the pump, the switch being positionable in a number of different positions whereby either one of the pump outlets can be selectively connected to the desolderer and the other vented to the atmosphere to prevent loading of the pump. In a neutral mode of operation, the desolderer is disconnected from the pump and both pump outlets are vented to the atmosphere to again prevent loading thereof. The switch also includes means for continuously varying the amount of air pressure applied to the desolderer.

Abstract: A valved cap is provided for the top of a riser pipe connected to a flow line under pressure such as may be found in irrigation systems and is normally closed when the system is in operation. The valve automatically opens when the system is stopped to admit air for preventing a vacuum build up and closes under pressure when the system is started up during which time air in the riser pipe is permitted to escape to avoid a pressure build up while the valve is closing. An apertured fitting connected to the valve stem within the riser pipe connects to a flexible air vent hose extending down the riser pipe and into the main flow line in the direction of the flow and air trapped in the riser pipe after the valve is closed is siphoned through the hose into the main flow line to be expelled into the atmosphere at an outlet in the main line.