Abstract: An improved water pressurizer comprises a pair of piston and plunger type intensifiers each driven by pressurized oil on one side of the piston and returned to the starting position by air pressure on the opposite side of the piston. Magnetic sensing switches detect proximity of the piston as it nears the end of a power or return stroke and send enabling signals to electropneumatic relays controlling air actuated ball valves on input and output oil lines. Because of the displacement volume and piston to plunger ratio, the intensifiers reciprocate at unusually low frequencies, reducing down time for maintenance or repair and thereby increasing reliability and capacity factor. Installed on a trailer for transportation, the apparatus can be attached to any available water supply for providing pressurized working fluid to a remote site.

Abstract: A hot water system comprising a hot water heater and conduit means coupled to feedwater under pressure for conducting water to and from the hot water heater. The system also includes an injector pump and a reverse osmosis module which has an inlet port, a product water port and a brine outlet port. The injector pump has an inlet coupled to the feedwater under pressure, a brine port coupled to the brine outlet port of the reverse osmosis module and a discharge port coupled to the conduit means. The injector pump includes a first valve operated by the injector pump for opening and closing the inlet of the injector pump. A second valve is provided between the reverse osmosis module and the brine port. The injector pump provides water to the inlet port of the reverse osmosis module and increases the pressure of the brine at the discharge port of the injector pump to greater than the pressure of the feedwater so that the brine can be injected into the hot water system.

Abstract: A pumping apparatus has a linear electric motor (10; 40) reciprocally driving motor pistons (16; 45) hydraulically coupled with pump pistons (25) or with coupling pistons (51) mechanically connected with pump pistons (61) which move the fluid to be pumped. For undersea use, the coupling arrangements allow convenient separation and retrieval of subassemblies requiring relatively frequent servicing.

Abstract: A pump driven by air pressure comprising an air cylinder, a piston in the cylinder to move up and down, an upper cylinder cap and a lower cylinder cap, a connector combined with a tubular projection of the upper cap for gas to flow through an interior of the connector, a valve base connected with a tubular projection of the lower cap, the piston moving up and down to move a tubular rod for changing gas flowing route and then forcing the piston to move in a reversed direction for pumping in liquid.

Abstract: The invention relates to a two-cylinder thick matter pump having a piston storage which is filled during the thick matter feed with the feed cylinders and evacuated by the hydrocontrolled storage piston into the feed pipe between the strokes of the feed pistons to reduce the pressure drop and the undelivered amount in the feed pipe. The inventive proposal is that the hydrocontrol of the storage piston (10) is served by a working piston (8) to be acted upon hydraulically on both sides, that is controlled with the feed cylinders and whose limits of travel, with the limits of travel of the storage piston (10), are fixed on the storage driving cylinder (7) when the storage cylinder (4) is fully evacuated and is filled.

Abstract: A chemical injector system for wells includes a solenoid operated valve delivering bursts of supply gas to a piston driven chemical injector pump. The solenoid valve allows very low cycle rates and also avoids plugging up of the gas supply line because the bursts of supply gas create high enough velocities to keep water and debris moving. A stand having a spike and a plate welded thereto supports the injector pump.

Abstract: A pump connectible to fluid under pressure comprising a housing having a cavity and a differential area piston reciprocable in the cavity on pumping and reset strokes and dividing the cavity into an inlet chamber, an outlet chamber and a reversing chamber. The housing has an inlet port communicating with the inlet chamber and connectible to the fluid under pressure, a water port communicating with the outlet chamber and a reversing port communicating with the reversing chamber. The piston has a passage leading from the inlet chamber to the outlet chamber. A first valve opens and closes the passage and a second valve is provided in the housing. A cam assembly opens and closes the first and second valves as a function of the position of the piston in the cavity.

Abstract: A proportioning pump for liquid additive metering having a housing with a diaphragm piston therein and inlet and outlet primary fluid lines to the housing and inlet and outlet valves in the housing for moving the piston up and down. A pair of additive pistons for pumping an additive liquid into the primary fluid with the additive pistons being moved by the diaphragm piston. An overcenter spring loaded connection connects the diaphragm piston to the inlet and outlet valves and a fail safe mechanism opens both the inlet and outlet valves in the event the spring in the overcenter connection fails. One of the additive pistons has an O-ring therein which acts as a seal and a check valve.

Abstract: A reverse osmosis system including a reverse osmosis filter with a reverse osmosis membrane and having an inlet port coupled to a source of feed water under predetermined pressure via a feed water inlet conduit, a product water outlet port for filtered outlet product water, and a brine outlet port for brine. A pump coupled into the feed water inlet conduit between the source of feed water and the inlet port of the filter and driven by the feed water under pressure. The pump increases the pressure of the feed water so that the reverse osmosis filter receives feed water at an increased pressure.

Abstract: A reciprocating actuator is axially connected to drive a reciprocating pump. An exhaust tube, open to the outside, passes through a piston of the reciprocating actuator and into an inner hole axially disposed in a working rod that connects an actuator piston of the reciprocating actuator to the reciprocating pump. A valve mechanism communicates a chamber above the actuator piston with the inner hole during upward motion of the piston, whereby actuator fluid above the piston is exhausted to the outside through the exhaust tube. The resulting axial exhausting of the actuating fluid permits inserting a large portion of the device into a drum for pumping of liquid. The invention permits use of a two-stage rod system, which is capable of obtaining high pumping pressure. The inner hole is communicated with a space whose volume changes when the working rod makes a vertical movement.

Abstract: An automatic solution mixing apparatus is provided with a plurality of solution distributors located on opposite sides of a common base plate supported on a supporting block. The support block is movable in opposite directions. Pistons of the solution distributors are connected to the common base plate so that dual solution mixing operations can be performed by the solution distributors with a high degree of accuracy. Moreover, a stepping motor is utilized as a driving motor, and the operation of the stepping motor can be controlled by controlling the number of pulses supplied to the driving motor without using a rotaty encoder.

Abstract: A safety shutdown circuit for a pneumatic pump system. The pump system includes a manifold assembly for discharging pumped liquid. The liquid is discharged from the system by a reciprocating piston apparatus which drives a liquid pump cylinder. The pump system is provided with a pneumatic safety circuit for monitoring the stroke time or rate of the reciprocating air cylinder. The safety circuit includes a safety shutdown valve and a pneumatic timer associated with the shutdown valve. The pneumatic timer vents air supply within the safety circuit after a predetermined time interval. If a leak or failure occurs in the pump system, the reciprocating piston apparatus will complete a stroke in less time than the predetermined time as a result of the pressure loss incident to the leak or failure. In such event, the air supply within the safety circuit is directed through the shutdown valve to the pump system START valve to deactivate the system.

Abstract: In the preferred and illustrated embodiment of a reciprocating pump, a plunger for pumping a liquid, a piston for reciprocating the plunger and a selector valve for changing a pilot flow passage between a supply passage communicating a pressure chamber with a supply port and a discharge passage communicating the pressure chamber with a discharge port are disclosed. The selector valve is switched by a pilot valve means. A pilot valve body of the pilot valve means is so designed to engage with the piston for predetermined distances to and from the ends of the respective forward and backward strokes of the piston and to be moved to the switching position where the pilot valve body opens one of the pilot supply passage working against the selector valve and the pilot discharge passage and close the other of the pilot passages and the pilot valve body is released from engagement with the piston and held at the switching position for a predetermined distance after the stroke of the piston is reversed.

Abstract: A fluid driven linear motor with a piston (4) in a cylinder (5) is supplied with driving fluid under the control of a sliding valve device (8) having a slide (9) being moved between its terminal positions and being retained therein by means of the driving fluid. A pilot rod (22) connected to the piston (4) controls the supply of driving fluid to the respective sides of the slide (9). The pilot rod (22) is slidingly received in a cavity (12) in the slide and has sections (23-25) of reduced diameter which act as valves in certain positions.

Abstract: A continually operating fluid pressure amplifier having a reciprocating piston system comprising a broad low pressure piston and a narrow high pressure piston, of which the latter, together with its piston cylinder, is arranged as a three-way pilot valve for operating a bistable control valve that controls the reciprocation of the piston system. The control valve has a primary valve slide controlling the said reciprocation and an auxiliary slide operable to open and close relevant conduit connections for initial amplification of the shift control signals governing the operation of the control valve, whereby a very safe operation of the entire system is ensured. Also ensured is a rapid return stroking of the piston system, such that the produced high pressure can be maintained substantially constant.

Abstract: Apparatus and method for pumping fluid from a wellbore using a reciprocating downhole pump, the downhole pump being reciprocated by a pumping unit which employs a hydraulic power cylinder means, the power cylinder being actuated with a variable displacement hydraulic pump.

Abstract: A reciprocating primary fluid driven motor has a stepped piston in a housing having a center hanging actuator rod which extends into the piston to periodically cooperate with an axially shiftable connector member in the piston which operates valves which establish the reciprocating stroke of the piston by opening and closing valve members on the larger and smaller faces of the stepped piston. A block member with compression spring drivers pivotally mounted inside the piston slides on the actuator rod during movement of the piston. The drivers are compressed in response to spaced stops on the actuator rod during continued movement of the piston until a sudden over-center movement of the block member shifts the connector to operate the valve members to cause reciprocation of the piston. Quiet operation during shifting is provided by shock absorbers. No sliding seal with the actuator rod is necessary. Provision for bleeding air from the housing chamber facilitates startup.

Abstract: Pump units comprising a metering reciprocating pump with adjustable length of stroke are used in packing machines for filling of packing containers with a metered quantity of flowable contents, e.g. yogurt. Adjustments in the length of stroke in order to adapt the amount of filling goods to the volume of the packing container interferes with the breaking sequence at the extreme position of the piston and alters the time for each pumping stroke. These drawbacks are avoided by means of an arrangement which includes a movable braking device for the piston as well as a valve arrangement which is linked to the braking device and serves to adapt the speed of the piston to the length of stroke.

Abstract: A hydraulically actuated downhole pump assembly for producing a well is powered by a fluid that is pumped downhole to an engine end thereof. The pump assembly has a pump end which is connected to a source of formation fluid so that the engine end drives the pump end and the pump end lifts produced fluid to the surface of the ground. The pump end has a pump barrel and a pump piston is reciprocatingly received in sealed relationship within the pump barrel. The engine end has an outer engine barrel, and an annular valve element is reciprocatingly received in sealed relationship within the outer barrel. The valve element moves up and down between two positions of operation while an engine piston reciprocates within the annular valve element and in so doing aligns various flow passageways in a manner to alternately apply power fluid to appropriate sides of the piston and valve element to force the engine piston to reciprocate.

Abstract: A lubricant pump that includes a pneumatic piston motor operated by compressed air, and is equipped with a control device that utilizes a slide valve mounted for reciprocal axial movement on the piston rod. A radially acting spring locking mechanism includes two index grooves spaced from each other axially along the piston rod, separated by the same predetermined distance that separates a first air inlet position and a second air inlet position of the piston slide valve. A helical compression spring is contained in a cavity within the piston slide valve. Axial movement of the reciprocating piston rod in one direction compresses the spring and releases the locking mechanism, whereupon the compressed spring immediately expands and moves the slide valve from one of its air inlet positions to the other of those positions.

Abstract: A nozzle arm is associated with an air-operated motor arranged to move the nozzle arm in a forward and return cycle across a headlight. The motor is a reversing air motor that includes a mixing chamber for pressured air and a cleaning fluid. The mixing chamber produces a mist under pressure that cleans the headlight in an efficient manner in one cycle of the arm. The motor is controlled in its movement by a cycling valve and an air operated relay valve. The nozzles on the nozzle arm are thin openings that form a pressured fan-like cleaning pattern.

Abstract: A bench top volumetric container filler is provided and consists of a mechanism to pump a predetermined amount of fluid from a reservoir into a container by using a volumetric piston pump operated by a vertical pump driving cylinder.

Abstract: An improved high pressure, piston pump has at least one two-piece telescoping cylinder having an end flange at one end and a housing containing piston drive means at the other end which are held together by tie rods passing through spacer tubes. The cylinder can be opened without loosening the tie rods to expose the piston and replace the piston seal.

Abstract: A proportioning pump for liquid additive metering having a housing with a diaphragm piston therein and inlet and outlet primary fluid lines to said housing for moving said diaphragm piston up and down. Additive pistons for pumping an additive liquid into said primary fluid with said additive pistons being moved by said diaphragm piston.

Abstract: An air-hydraulic pump incorporates a primary pumping mechanism for supplying a first level of fluid pressure to a work-performing tool at a first flow rate in response to a supply of pressurized air. An auxiliary pumping mechanism is provided for delivering a second level of hydraulic fluid pressure less than the first level at a flow rate greater than the first flow rate. The auxiliary pumping mechanism provides sufficient pressure to overcome a load on the system up to a predetermined level, after which the auxiliary pumping mechanism ceases operation due to such load and the primary pumping mechanism delivers fluid pressure to the system sufficient to overcome the load. The auxiliary pumping mechanism speeds up operation of the work-performing tool for providing time-saving operation thereof.

Abstract: The objective of the present invention is to provide a reciprocation switching device for a pump which will solve problems of conventional devices such as that, because coil springs are used for activating by their snap action valve operators or switching operators serving to control the pressure of pump working fluid in relation to reciprocating action of the pump, such devices require the numerous number of parts including spring fitting shafts, the structure to attach such fitting shafts, parts for spring holders, etc.; and that the assembling of those parts is troublesome. A device according to the present invention uses one or two springs made into a C-like shape as the springs for the aforementioned purpose and calls for fitting said springs directly between the spring fitting section(s) and the valve operator or the switching operator.

Abstract: A reverse osmosis system including a reverse osmosis filter with a reverse osmosis membrane and having an inlet port coupled to a source of feed water under predetermined pressure via a feed water inlet conduit, a product water outlet port for filtered outlet product water, and a brine outlet port for brine. A pump coupled into the feed water inlet conduit between the source of feed water and the inlet port of the filter and driven by the feed water under pressure. The pump increases the pressure of the feed water so that the reverse osmosis filter receives feed water at an increased pressure.

Abstract: A sub-surface hydraulically operated engine for reciprocating an oilwell pumping unit includes confined hydraulic fluid means for actuating a reversing valve and its lifter in order to change the upstroke motion to downstroke motion and vice-versa.

Abstract: A pump assembly or for pumping one or more fluids includes a drive piston pump which reciprocates to drive proportion pumps. Fluid to the drive piston pump is controlled through a pair of two-position, three-port valves which communicate pressurized fluid sequentially above and below the drive pump piston to reciprocate the piston. While applying fluid pressure to one face of the piston, the opposite face is vented to tank such that no back pressure exists in the system. A proportion pump is provided for each fluid pumped by the system and is designed to pump upon movement in either direction. A check valve is fitted on the outlet of the proportion pump to maintain constant pressure in the hose attached to the proportion pump and to prevent back flow of fluid from the hose into the system. The hose is of sufficient length so as to modulate any variations in the pumping pressure.

Abstract: An energy recovery pump-motor including an energy recovery pump and a mixed-phase motor for replacing conventional valves in fluid circuits such as an absorption refrigeration system. The energy recovery pump pressurizes a first liquid by recovering flow work energy from a second liquid. The mixed-phase motor recovers flow work energy and expansion energy from a high pressure, saturated third liquid and transfers the energy along a shaft to the pump to aid in pressurizing the first liquid. The energy recovery pump is shown in a single effect absorption refrigeration system, while the pump-motor is shown in both single effect and double effect systems.

Abstract: A fluid flow machine wherein a reciprocating piston type pump for a flowable material which must be subjected to a pronounced pressurizing action is operated by a double-acting pneumatic motor which is disposed at a level above and is spaced apart from the pump. The unit which regulates the admission of compressed air into and the evacuation of spent air from the motor is installed between the motor and the pump at a level immediately above a chamber for a supply of liquid medium serving to lubricate and clean the piston rod which transmits motion from the piston of the motor to the pump piston. A common cylindrical envelope which is permeable to air surrounds the motor and the regulating unit and defines a large expansion chamber for spent air to thus reduce noise when the machine is in use.

Abstract: Pump for liquids and gases, particularly for immersing in a well hole. A pump piston (35) is operated by a double acting operating piston (33) provided with working medium through a supply conduit (13). The supply of working medium to the respective sides of the operating piston (33) is controlled by a reversing valve (34). This has a slide (45) being operated by the operating piston (33).

Abstract: This invention relates to a pumping device that is adaptable for commercial and residential use that incorporates a series of pistons and valves that automatically and proportionally injects such fluids as fertilizers, oils, soaps and food syrups into various other liquid mediums.

Abstract: An improved portioning assembly adapted for use in the precise portioning of food or other products is provided which makes use of a double-acting piston and cylinder assembly shiftable between defined limits, with the stroke length of the piston being correlated with the quantity of dispensed portions. The preferred overall portioning assembly includes a hydraulically operated product pump coupled with the control piston and cylinder assembly for sequential product-dispensing movement thereof; movement of the control piston between spaced limits serves to actuate associated limit switches, the latter operating a valve for directing pressurized charges of hydraulic fluid to the hydraulic pumping chamber. If desired, a delay can be provided before the initiation of each product-dispensing stroke of the control piston.

Abstract: The present invention relates to an improved cylinder pump. The cylinder pump includes air hoists enabling the entire pump assembly to be lifted so that a container may be placed thereunder and thereafter the air hoists may be biased downwardly so that the follower plate of the pump mechanism will bear down on top of the liquid contained within the container. Thereafter, the air cylinder of the pump is activated and reciprocated up and down through the provision of a four port reversing valve activated through the use of air sensors to cause the pump to pump fluid out of the container while the downward bias of the air hoists keeps the follower plate in contact with the surface of the liquid within the container. By separating the air cylinder actuator for the pump mechanism from the four port reversing valve thereof, improved reliability and quietness are attained.

Abstract: A pilot control valve comprising an elongated valve member shiftable within a valve body between a first and a second position. The first position allows communication of control fluid to a first pressure receiving surface to initiate movement of the valve member from its first position to a position equalizing the pressure acting on a second pressure receiving surface with the pressure of the control fluid, thereby causing the valve member to move to its second position. The valve member when in its second position allows communication with a third pressure receiving surface for initially moving the valve member from its second position while equalizing the pressure acting on the second pressure receiving surface to move the valve member to a position equalizing the pressure acting on the second pressure receiving surface with a pressure lower than the pressure of the control fluid for moving the valve member to its first position whereby the operation is repeated at infinitum.

Abstract: A well pumping unit comprising a double acting hydraulic cylinder actuator supported on a mast above a wellhead and having a piston rod connected directly to the polish rod of an elongated subsurface pump rod string. A generally cylindrical annular counterweight is disposed around the mast and is interconnected with the cylinder actuator by flexible chains trained over crown sheaves and travelling sheaves connected to the upper piston rod offsetting the weight of the pump rod string and at least a portion of the weight of the fluid column in the well. The pumping unit is controlled by a hydraulic control system including a directional control valve and flow control valves for selectively controlling the strokes of the cylinder actuator. A hydraulic pressure load sensing system measures total load on the rod string and provides for automatic shutdown of the actuator if the fluid level in the well is pumped below a predetermined level.

Abstract: The invention relates to a device for injecting a metered product into a main circulation of liquid, comprising a metering piston (28) coupled to a stepped piston (11) whose motion results from the pressure of the main fluid in a known manner. The piston (28) interacts with a metering cylinder (10) which is in permanent communication with the lower part of the liquid outlet chamber (8). The mixture of the products is thus confined to the outlet of the device, while no leakproof sliding of a component on contact with either of the liquid and product is necessary, and this eliminates the risks of abrasion of the seals due to deposits on the sliding component. In addition, since the inlet chamber (6) for the main liquid is annular, it permits a filter (33) to be easily installed.

Abstract: A lubrication system for a mechanism including a differential pump for pumping lubricant into the mechanism powered by the flow of a first lubricant from a parallel lubrication system within the mechanism.

Abstract: A multiple fluid pumping system uses two or more fluid pumps each driven by a pneumatic piston or plunger and cylinder combination whose piston top stroke and bottom stroke positions are detected by reed switches in combination with a magnet attached to the piston. The top stroke reed switches are connected in series with one side of a two position pneumatic solenoid valve while the bottom stroke reed switches are connected in series with the other side of a two position penumatic solenoid valve. The circuit is designed to prevent one of the pistons from changing the direction of its stroke prior to the other piston reaching the end of its stroke. A further embodiment utilizes a magnet mounted on one pneumatically driven piston or plunger and a pair of reed switches mounted on the other penumatically driven piston or plunger to prevent one piston or plunger from moving faster or slover than the other piston or plunger.

Abstract: An air-operated reciprocating pump is designed for use with a wide variety of materials having widely varying viscosities. The pump has a stroke which is adjustable so that the piston can operate either entirely within the cylinder or can extend out the bottom end of the cylinder at the end of the stroke for materials having an extremely high viscosity. The stroke adjustment is easily accessible in the area between the pump and the air motor.

Abstract: A hydraulic actuated pressure booster unit includes a differential power piston and an integral control valve controlling the pumping direction and action. The control valve has a reciprocally mounted tubular spool member in a cylinder valve body. The spool member has a control passageway and a plurality of spaced spools, one of which mates with the power piston passage to form a first valve for transfer of oil to the pumping chamber and from a transfer chamber to an exhaust passageway. A pair of spaced spools slide in stepped control chamber forming a control bore and exhaust bore connected by the spool passageway to the pumping chamber via the first valve. A sequence valve connects the exhaust bore to the exhaust through a directional control valve. The sequence valve is controlled by the output working pressure. A pilot valve controls the load connection to the one end of the cylinder and a high pressure relief valve limits the total pressure created within the working system.

Abstract: An electronically controlled, pneumatically actuated pumping system is provided that is especially designed for the precision dispensing of liquids. The system includes a positively actuated inlet valve, and a small-diameter, long-stroke pumping piston that is physically stopped at each end of its stroke. The unique inlet valve and piston enable the system to repetitively dispense metered volumes of fluid at better than one tenth of one percent accuracy. A unique calibration mechanism and detachable dispensing head allow for the rapid disassembly, cleaning, and reassembly of the system. An alternative embodiment of the pumping system incorporates a plurality of dispensing nozzles controlled by a single inlet valve and pumping piston combination. The dispensing unit may be shiftably mounted on a vertically oriented stand, and may be automatically shifted upwardly as fluid is dispensed to minimize splashing and atomizing of the dispensed fluid.

Abstract: An improved variable proportioner is provided which includes a spring biased lost motion connection between the motor piston and the slave pump piston thus providing for accurate adjustability of the metering proportion as well as prevention of stalling of the slave piston against the front cylinder wall. A pivotable connection of the toggle lever spring is also provided to reduce bending of the spring and to enhance its life span.

Abstract: A reciprocating ram pump of the well known Willett's type is provided with electrical sensors (S1 and S2) and a solenoid operated valve (56) for controlling reversal of the ram at its delivery and suction stroke limits. The sensor outputs are employed for the purpose of counting the number of strokes executed by the ram in a counting circuit (22) which can be preset by means of keyboard (26) to count until a stroke count corresponding to the preset value (or a threshold value close thereto) as been reached whereupon a warning signal may be produced. The number of strokes counted may be indicated on display (28) for example after conversion into a parameter such as total volume delivered. The preset value entered from the keyboard (26) may likewise be displayed. The sensor outputs may additionally be employed to control a timing circuit (24) which can be preset to time a certain interval corresponding to the delivery stroke rate of the pump falling to or below a certain level.

Abstract: A downhole hydraulically actuated pump assembly of either the free or fixed type lifts formation fluid from the bottom of a borehole to the surface of the ground. The downhole pump has a power piston which actuates a production plunger. A valve means is concentrically arranged within the power piston. A stationary, hollow valve control rod extends through the power piston and through the valve means, with a lower marginal end of the control rod terminating within the production plunger. Power fluid flows through the control rod and to the valve means. As the power piston reciprocates within the engine cylinder, means on the control rod actuates the valve means between two alternant positions so that power fluid is applied to the bottom face of the power piston to thereby cause the power piston to reciprocate upward; and thereafter, the control rod causes the valve means to shift to the other position, whereupon spent power fluid is exhausted from the engine cylinder.

Abstract: A chemical pump includes an access sleeve positioned between a hydraulic driving cylinder and the chemical injection cylinder with a rod coupled between the hydraulic driving piston and the injection piston. The access sleeve structurally secures the driving cylinder to the injection cylinder and includes access ports through a sidewall thereof such that when the injection piston is withdrawn into the sleeve, the seals are accessible for replacement or other piston maintenance. According to another aspect of the invention, the diameter of the hydraulic piston is substantially greater than that of the injection piston.

Abstract: A multiple-mode, multiplex pumping apparatus includes circuit control elements for initializing the apparatus by placing each of the pistons and plungers in each pumping section of the multiplex pumping apparatus at a respective initial starting point. The pumping apparatus also includes electronic circuit elements for controlling the inlet valves, exhaust valves and precompression valves of the hydraulic circuit of the pumping apparatus. The apparatus includes phase control circuit elements for controlling the separation of the leading edges of the plungers of two of the pumping sections of the apparatus when the apparatus is operating as a quadruplex pump. The pumping apparatus also includes elecrtronic circuit elements for insuring that each plunger of each pumping section stops at a fixed stopping point. The apparatus also includes electronic circuit elements for controlling the volume of fluid in the rod end portions of each of the pumping sections.

Abstract: A hydraulically-driven pump of the displacement type intended particularly for pumping various suspensions of liquids and solid particles (slurry) and/or for high pumping pressures comprises a pump housing with a pump chamber (4) with an inlet pipe and an outlet pipe, and associated inlet, and outlet valve, respectively, and a pump piston, disc (16) or corresponding provided in the pump chamber.

Abstract: A system for providing a high pressure pulsating flow of cutting fluid includes a piston pump having a piston cylinder for pumping the cutting fluid and an air cylinder for reciprocatingly actuating the piston cylinder. An air-operated direction change-over valve controls supplying of air to one end of the air cylinder or the other from a compressed air source. A pulse frequency setting unit, including a fluidic NOT device, controls the position of the change-over valve pneumatically thereby determining the frequency of reciprocation of the air cylinder and thereby the frequency of pulsations in flow of the cutting fluid.