GB2185090A - Improved control valve for water pump system - Google Patents

Abstract

A water pressure booster system is for regulating water pressure in a piping system having a pump (10) connected to a water supply. A control device (214) regulates the pressure in the distribution system via a closely balanced piston valve (36). Flow into the system from pump (10) is controlled by throttle valve (74), actuated by the pressure differential between the system pressure and a constant pressure acting on a closely balanced piston (72). Biasing spring (206) loads the throttle valve (74) in its closed position. The device includes a housing (34) having an inlet (40) connected to outlet (10) and first outlet (46) connected to the piping system (120). Valve member (36) has no biasing means and is freely slidable therein. The pressure acting on the lower side of piston (72) is regulated by pressure regulator (38). This is a venturi (130), the inlet (224) of which is connected to the outlet (228) of the flow regulator (150). Flow regulator (150) and venturi (130) allow operation of the device (214) without flow regulator (38) back to the suction-side of the pump (10) and without requiring the additional pressure drop caused by a basing spring (206). <IMAGE>

Description

SPECIFICATION Improved control valve for water pump system The invention relates to water pumping systems, particularly well water systems, and, more particularly, to control valves for such systems.

Water supply systems using water supplied by a pump are well known. Such water supply systems usually include booster systems which generaliy serve to maintain water pressure in tall buildings or in smaller buildings located in areas which have inadequate or antiquated municipal water supply sys tems, and well water systems which draw water from an u nderground water sou rce and supply it to a distribution system at a pressure suitable for use.

Typical prior art pumped water systems have included a motor driven pump connected to the water supply source, such as a well or municipal supply system, and a pressure actuated switch connected to switch the pump on and off in dependence to building water pressure. The aforedescribed system meets the basic requirements of a booster system, however, it results in frequent on-off cycling of the motor and pump, since any opening of a faucet would reduce the pressure in the system enough to turn on the pump. To prevent excessive pump cycling, such systems can include a water accumulator which stores a limited amount of water under pressure in orderthatsmall amounts of water can be provided without switching the pump on.Afurther re finementto such systems includes a water pressure control device which delivers water for use at a relatively constant pressure and which, by limiting the output pressure when the pump is operating, prevents the pressure switch from opening as long as there is a sufficient demand for water. The pressure control device can include a time delayfeature, which acts to restrict the rate of pressure build-up when the demand for water ceases, thereby acting to delay the switching-off of the pump.

An accumulatortank in the system provides water under pressure to the system for relatively small amounts drawn off by opening the service faucets without the necessity of turning on the pump and motor. U.S. Patent Nos. 3,739,810,3,782,858, 3,814,543,3,865,512,3,871,792,3,876,336 and 3,922,111 describe water pressure booster systems pertinent to the above.

Prior art booster systems generally utilized a diaphragm actuated valve to regulate the pressure in the system and to control the refilling of the accumu- latortank. Some of the prior art booster systems use a pilot pressure in conjunction with the diaphragm to control the position of the valve, while others used biasing means, such as a spring or pneumatic pressure.

The diaphragm in such control valves is subject to failure both through rupture and through ineffective sealing about its periphery. Also, in those systems which used biasing means along with the dia phragm, the biasing means must exert sufficient force on the valve member to overcome anyfrictional forces to insure closing of the valve. This clearly increasesthe force necessaryto open the valve and, consequently, increasesthe pressure drop through the control valve.

Prior art booster systems which used a pilot pressure to control the main valve position usually require an additional check valve to prevent the accumulatorfrom discharging backthrough the pump.

This results in a booster system which is unnecessarily complex and usually entails increased maintenance and increased chances of system malfunction. Water pumping systemsforwells usually have the check valve atthe pump site in the bottom ofthewell.

U.S. Patent No.4,165,951 discloses a water pressure booster system having a control device which regulates the pressure in the distribution system via a closely balanced piston valve. Flow into the system from a pump is controlled byathrottiingvalvewhich is actuated by the pressure differential between the system pressure and a constant pressure acting on a closely balanced piston. Flow from the system back into the pump is prevented by a flow control/check valve within the throttling valve. One limitation of the system of Patent '951 is the requirementto discharge an amount offlow necessary to regulate the pressure acting on the balanced piston. Such flow can be discharged to drain; otherwise, it can be discharged back to the suction side of the pump.The latter situation is illustrated in Figure 1 of Patent '951 (which is the same as Figure 1 ofthis application). Theflow passing through orifice 80 in balance piston 72, which is regulated by the back pressure regulator, is discharged to the suction side of pump 10. This is a satisfactory expedient in the case of a booster pump, since the pressure control device can be placed in close proximity to the pump; but this may not be a practical solution in the case of a deep well pump, in which case the pressure control device is usually situated at ground level,whilethe pump may be located at the base of a well up to several hundred feet below ground.

The reason it is necessary to discharge the back pressure regulatorflowto the suction side of the pump is that, in the device depicted in Figure 1 of Patent '951, the pressure of the water in chamber 84 is at or near the pressure on the discharge side ofthe pressure regulator in passage 46 and that after allo wance forthe pressure drop through the pressure re- gulator, the fluid pressure at the outlet ofthe back pressure regulator is less than that in passage 46.

Since the back pressure regulator cannot discharge to a higher pressure, it is necessary to direct itto the low pressuresuction side ofthe pump (ortodrain).

Attention is also drawn to U.S. Patent Nos.

4,471,907,4,165,951,2,761,389,3,141,475,1,656,132, 3,304,048,2,454,929,3,694,105,3,799,199,2,360,816, 2,712,322,2,732,810,4,004,610,2,829,670,2,911,010, 3,385,216,3,756,558, 3,873,063,2,127,172, 2,219,070, 3,902,522,2,563,889,2,975,803,3,399,696,3,613,716, 3,669,143 and 3,703,911. Attention is also drawn to the following foreign patents: French Patent No.

1,479,426; French Patent No.2,382,636; French Patent No.904,652; French Patent No.2,092,270; French Patent No.857,540; French Patent No.

2,175,391; French Patent No.868,263; German AS 1,293,034; German OS 2,400,636: German AS 1,146,007; and German Patent No.937,866.

It is an object ofthe invention to provide a water pumping system having a control valve which avoids and/or overcomes the above-described limitations and disadvantages of the prior art. It is another object ofthe invention to provide a water pumping system having a control valve which regulates the pressure ofwater delivered within a narrow band and accomplishes such with low loss of pressure at high flow rates. It is a further object ofthe invention to provide such a control valve capable of overcoming large frictional resistance as can be caused by foreign matter entering the valve or by accumulation of fouling within the valve. It is a still further object of the invention to provide such a control valve thateliminates the requirement to recirculate water to the suction side of the pump orto drain.It is another ob ject of the invention to provide a time delay so asto permit continued pump operation after cessation of demand. Itis anotherobjectofthe invention to provide a control valve which is of compact design and low in cost. It is another object of one embodiment of the invention to provide a control valve which does not require the use of springs as direct biasing means. It is another object of the invention to provide a control valve which does not require the use of diaphragms as direct biasing means. Other objects and advantages of the invention are set out herein or are obvious herefrom to one skilled in the art.

The advantages and objects of the invention are achieved by the control valve ofthe invention and the water pumping system having a control valve of the invention.

The first embodiment of the invention relates to a water pumping system having a control valve which obviates the deficiencies of the aforementioned prior art devices. The system comprises a motor driven pump connected to a water supply source, an ac cumulatortank, a pressure switch responsiveto water pressure in the system forturning the pump motor on and off, a control valve connected between the accumulator and pump, and a service outlet valve such as a faucet or the like.

The control valve ofthe first embodiment re gulatesthe water pressure in the system and also controls the refilling ofthe accumulatortank afterthe demand for water at the service outlet valve has closed. The valve is a closely balanced piston type, as opposed to the diaphragm valves of the priorart booster systems, and has an inlet connected to the pump outlets connected to the accumulatortank, and to the system. The inlet from the pump is located between a throttle valve portion and a balance piston portion ofaslidablevalve member, such thatthe pump pressure forces on the valve member cancel each otheroutand do nottendto move the valve member in either direction.A biasing spring is positioned against the top of the throttle valve portion and in the valve casing chamberwhich communicates with the inlet and outlet The balance piston portion has an orifice therethrough to allow passage of water past the piston into a chamberto produce a back pressure which tends to raise the piston forces, thereby opening the throttle valve portion and allowing communication between the pump and the remainderofthe system. The magnitude of the back pressure is determined, in part, by a miniaturized back pressure regulating device con nected to the valve housing and remains at a re latively constant level. The regulating device does not need to be part of the valve, but can be separately connected to the housing.

The throttle valve portion is acted on by the system pressure which tends to close the throttle valve. The back pressure regulatorflow problem is eliminated by means of the biasing spring which is used to load the throttle valve in the closed posjtion. Thus, it can be seen that the movement of the yalve member is controlled solely by the differentia'l between the combination spring load and system pressure and a relatively constant back pressure.

Thethrottlevalve portion may contain a combination flow regulator/check valve which allows a small quantity of waterto flow (in addition to the flow from the back pressure regulator) into the system after the system pressure has closed the throttle valve por tion.Thispermitsthepumpand motortokeeprunn- ing afterthe demand at the service outlet faucet has ceased so as to refill the accumulatortank. Afterthe accumulatortank reaches a predetermined pressure, the pressure switch turns offthe pump motor and the flow regulator/check valve closes to prevent backflow from the system to the pump.As the invention primarily involves well water systems where the check valve is located atthe pump site at the bottom of the well - i n such cases the com bi nation flow re- gulator/checkvalve is not a necessary part of the invention control valve.

The effect of the biasing spring isto requirethe pressure in the chamber below the balance piston portion to be greater than that in the passage (chamber) above the throttle valve portion in orderto balance the forces acting on the slidable valve member assembly. As long as the pressure drop through the back pressure regulator is low enough, theflowthrough orifice in the balance piston portion can be caused to flow into the chamber on the discharge side ofthe pressure control device. This technique eliminates the need to feed flow back to the suction side of the pump, but it does require thatthe pressure drop through the pressure control device be at least as great as the effective pressure ofthe biasing spring, that is, the spring force divided by the throttle valve area. The additional pressure drop caused by the biasing spring can be substantial in contrast to the pressure drop of the water pressure control device disclosed by U.S. Patent No.

4,165,951.

Another or second embodiment of the invention involves a water pressure booster system for regulating water pressure in a piping system having pumping means connected to a water supply. The means for controlling water flow into the piping system includes a housing having an inlet passage connected to an outlet of the pum pi ng means and a first outlet connected to the piping system. Avalve member is contained within the housing without biasing means so as to be freely slidable therein. The valve member has a throttle valve and a balance piston connected to thethrottle valve. There is back pressure regulating means to regulate the pressure acting on the side of the balance piston facing away from the throttle valve. The back pressure regulating means is interconnected between the side of the piston and a second outlet in the housing.The main part of the second embodiment involves flow re gulating means and venturi means. The flow regulating means has an inlet connected to the connection between the outletofthe pumping means and the inlet passage of the housing. The flow regulating means also has an outlet. The venturi means has an inlet, a throat and an outlet.Theinletoftheventuri means is connected to the outlet ofthe flow regulating means. The outlet of the venturi means is connected to the piping system which is connected to the first outlet of the housing. The zone of lowest pressure in the venturi means, which is generaily between the venturi inlet and the throat, is connected to the second outlet in the housing. In one version, the throat ofthe venturi means is connected to the second outlet in the housing.In another version, a deformable disc having a central passageway is located in the mouth oftheventuri means per pendicular or approximately perpendicular to the longitudinal central axis of the venturi means. This provides a jet pump or aspirator so that the lowest pressure point occurs between the deformable disc andthethroatoftheventuri means-the connection to the outlet in the housing is located in the venturi mouth at such lowest pressure point.

The flow regulating means controls the rate of flow that may bypass the valve means, such that when the throttle valve is closed, the rate of flow at which the accumulatortank is refilled may be kept relatively constant. This provides a reproducable pump offdelay time.

The pressure control device ofthe second embodiment has the low pressure drop attributes of the priorart,while eliminating the need to recirculate flow back to the pump inlet.

The second embodiment provides use ofthe pressure control valve without feeding flow from its backpressure regulator back to the suction-side of the pump and without requiring the additional pressure drop caused by a biasing spring. This enables such a pressure control valve to be located remotely from the water pump, as in the case of a submerged deep well pump.

Preferablytheflowregulating meansandtheven- turi means are combined in one housing. Most preferablytheflow regulating means (in the combined embodiment) comprises a deformable disc having a central passageway therein. The disc is located so that the central passageway is aligned approximately parallel with and in the center of the flow in the venturi means. The disc also is located nearthe throat of the venturi means thereby serving as the inletoftheventuri means.

The water pressure boostersystem comprises a motor driven pump connected to a water supply source, a check valve, an accumulatortank, a pressure switch responsive to water pressure in the system forturning the pump motor on and off, a control valve connected between the accumulator and pump, and a service outlet valve such as a faucet or the like. The control valve regulates the water pressure in the system and also controls the refilling of the accumulatortank after the demand for water at the service outlet valve has ceased or diminished.

The valve is a closely balanced piston actuated type, as opposed to the diaphragm actuated valves of the prior art booster systems, and has an inlet connected to the pump and outlets connected to the accumula tortank, and to the system. The inlet from the pump is located between a throttle valve portion and a balance piston portion of a slidable valve member, such that the pump pressure forces on the valve member to cancel each other out and do not tend to move the valve member in either direction.

The magnitude ofthe pressure acting on the back of the balance piston is determined by a pilot back pressure regulating device connected to the valve housing and remains at a relatively constant level.

The throttle valve portion is acted on by the system pressure which tends to close the throttle valve.

Thus, it can be seen thatthe movement ofthevalve member is controlied solely by the differential between the system pressure and a relatively constant back pressure without the necessity of diaphragms, springs, or other biasing means.

The throttle valve portion can contain a flow regulatorwhich allows a small quantity of water (in addition to the flow through the back pressure regulator) to flow into the system after the system pressure has closed the throttle valve portion. This permits the pump and motor to keep running after the demand at the service outlet faucet has ceased so as to refill the accumulatortank. After the accumula tortankreachesa predetermined pressure,thepressure switch turns off the pump motor and the system check valve closes to prevent backflow from the system.

In the drawings: Figure lisa schematic representation of a prior art water pressure booster system according to U.S.

Patent No.4,165,951; Figure 2 is a cross-sectional view of the prior art control valve of Figure 1; Figure 3 is an enlarged cross-sectional view of an alternative embodiment of the prior art throttle valve of Figure 2; Figure 4to 6 are sequential views showing, in cross-section,the operational portions ofthe prior art valve of Figure 2 during operation of the prior art booster system of Figure 1; Figures 7a and 7b are cross-sectional views of the first embodiment of the control valve of the invention; Figures 8a and 8b are schematic representations of one version ofthe second embodiment ofthe water pressure booster system of the invention including a cross-sectional view of one version of the control valve of the second embodiment of the invention; ; Figures 9a and 9b are representations of another version of the second embodiment of the water pressure booster system of the invention including a cross-sectional view of a combination of the Venturi device and flow regulator and a cross-sectional view ofthe control vaive of Figures 8a and 8b; and Figures lOa and lOb are cross-sectional views of a further version ofthe second embodiment of the junction between the supply conduit and the conduit leading to the flow regulator used in conjunction with the control valve ofthe second embodiment of the invention.

The control valves ofthe invention are definitive improvements overthe control valve of U.S. Patent No. 4,165,951,so the latter is first discussed and described herein. The prior artwater pressure booster system of U.S. Patent No. 4,165,951 is shown diagrammatically in Figure 1, and comprises water pump 10 driven by electric motor 12, control valve assembly 14, accumulatortank 16 and pressure ac tuatedswitch 18. Pump 10,which can beanytypeof pump suitable for a specific application (such as, a shallow well pump), has its inlet connected to a sourceofwaterwhich can be awell ormunicipal water supply system, via conduit 20. The outlet of pump 10 is connected to control valve assembly 14 via conduit 22.Control valve assembly 14 has a through passage connected to one side to accumulator 16 and pressure switch 18 by conduits 26 and 24, respectiveiy, and on the other side to the building piping distribution system shown diagrammatically by conduit 28 and service outletfaucet30. Figure 1 is only a diagrammatic representation and any number of faucets and outlets can be provided throughout the building.

Accumulator 16 and pressure switch 18 can be standard, commercially available items. For ex- ample, accumulator 16 can be WELL-X-TROL Model WX-202 made byAmtrol Inc., while pressure switch can be that incorporated in the aforementioned pump. WELL-X-TROL is a registered trademark of Amtrol, Inc., (of 1400 Division Road, West Wa rwick, Rhode Island, 02893.) in U.S.A.

Motor 12 is connected to a source of electrical power via power supply cable 32 through pressure switch 18. the location ofthe pressure booster system so permits electric motor 12 can be replaced byan internal combustion engine, oranyother power source to drive pump 10.

Control valve assembly 14 is shown in detail in Figure 2 and comprises housing 34, slidable valve member assembly 36 and back pressure regulator assembly38. Housing 34 has inlet passage 40 connected to the outlet of pump 10 via standard threaded connections and conduit 22. A similar passage 42 is provided for connection to accumulatortank 16.

Another passage 46 is provided, coaxially aligned with passage 42, to allow connection ofcontrol va Ive assembly 14to service outlet faucets 30. This passage extends perpendicularly from the plane of Figure 2 and is shown schematically in Figure 1.

Housing 34 also has threaded passages 48 and 50 for connection to a pressure gage, and to the inlet conduit 20, respectively. Access plug 52 is threaded into the top of housing 34to facilitate the installation and removal of valve member assembly 36. Access plug 52 has annulardepending skirt 54 extending into housing 34to limit the upward movementofvalve member assembly 36. Passage 56 can be provided in access plug 52to connect pressure switch 18 with a source of line pressure.

The lower portion of housing 34 is connected to back pressure regulator assembly 38. Regulator assembly 38 can be attached directly to housing 34, as shown in Figure 2, or can be separate therefrom and be connected via a conduit. Regulator assembly 38 can also be a standard, off-the-shelf item. Generally, regulator assembly 38 comprises: housing 58, which can bethreadingly engaged with housing 34; diaphragm 60, which extends across and sealsthe open end of housing 58; screw 62, which threadingly engages housing 58; and spring 64, which extends between screw 62 and diaphragm 60, normally biasing sealing member 66, which is attached to dia phragm 60, against the bottom of housing 34 thereby sealing off passage 68.As can be seen, passage 68 communicates with aforedescribed passage 50.

Valve member assembly 36 has central shaft 70 with balance piston 72 on its lower end, and throttle valve 74 on its upper end. Balance piston 72 has peripheral sealing means 76to effect a seal between it and inner surface 78 of housing 34. Orifice 80 is provided through balance piston 72 to allow fluid communication between central chamber 82 and lower chamber 84 within housing 34. Orifice 80 has across- sectional area of approximately 0.001 to 0.005 sq. in.

Lower chamber 84 also communicates with back pressure regulator assembly 38 via passage 86.

Throttle valve 74 has a plurality of longitudinal valve guides 88 circumferentially displaced about its periphery. Guides 88 keep the longitudinal centerline of valve member assembly 36 coincidentwith the centerline of housing 34 during upward and downward movement of valve member assembly 36. The outer surface ofthrottle valve 74 is shaped such that it throttles the flow of fluid between central chamber 82 and upper chamber 90. This cap be achieved by forming the outersurface in the shape oftruncated cones having increasing side angles, as shown in Figure 2, or by forming the outer surface in the shape of a truncated paraboloid, as shown in Figure 3.In either case, the rate offlow between central chamber 82 and upper chambergwill increase as valve member assembly 36 moves upwardly.

When valve member assembly 36 is in its lowermost position, as shown in Figure2,fluidcommunic- ation between central chamber 82 and upper chamber 90 is normally prevented by sealing member 92, which is attached to valve member assembly 36, bearing against valve seat 94 defined by the upper surface of cylindrical inner projection 96 of housing 34.

The upper portion of valve member assembly 36 also contains flow regulator/valve 98. Valve 98 is free to move between lower valve seat 100 and upper valve seat 102, depending upon the pressure differential between central chamber 82 and upper chamber 90. When the pressure in upper chamber 90 is greater than that in central chamber 82, flow re- gulator/checkvalve 98 will be pushed upwardly and engage valve seat 102. Valve seat 102 has at least one, and preferably a plurality, of radial grooves 204 emanating from the opening of passage 104 and extending to the outer circumference of seat 102 such that it allows passage offluid even when checkvaive 98 engages seat 102.If two grooves 204 are used, a width of 0.080" to 0.200"and a depth of 0.040" to 0.080" are sufficient to provide a flow rate of approximately 0.5 to 1.0 gallons per minute from the pump into the system through valve 14. Flow regulator/check valve 98 is made of resilient material having a durometer of 40 to 70. Fluid will pass from cen tral cham ber 82, th roug h passage 106, around the periphery of check valve 98, through radial grooves 204, and into passage 104. The purpose of allowing passage offluid past check valve 98 when in this position will be described hereinafter.

When checkvalve 98 engages valve seat 100, flow pastthecheckvalvebetween upperchamber90and central chamber 82 is prevented.

Screen 108 can be provided between the throttle valve portion and balance piston 72to preventdirt and other foreign matter from clogging or blocking the various passages in valve member assembly 36.

The operation of the prior art system and the prior art control valve of U.S. Patent No.4,165,951 described as follows with particular reference to Figures 4 06. As starting conditions, it is assumed that service outlet faucet 30 is closed, motor 12 and pump 10 are off, accumulator 16 is filled to capacity, and valve member assembly 36 and check valve 98 are in the positions as shown in Figure 4. Once service outlet faucet 30 is opened, the requisite water is initially supplied from the water in the piping system and that in accumulator 16. If the demand is sufficiently great, the pressure in conduits 24,26 and 28 drops to the set point of pressure switch 18. At such point, pressure switch 18 completes the circuit and turns on motor 12 and pump 10.The outputfrom pump 10 enters control valve assembly 14through passage 40. The diameters of balance piston 72 and throttle valve 74 are equal. The force on balance piston 72 is equal and opposite to that on throttle valve 74, there- fore the pressure of fluid entering passage 40 does not move valve member assembly 36 in either direction.

Once such pilot pressure acting on the lower side of balance piston 72 exceeds the system pressure present in upper chamber 90, valve member assembly 36 moves upwardly, unseating sealing member 92. Flow control/check valve 98 also moves upwardly, as shown in Figure 5, when the pressure in central chamber 82 exceeds the system pressure.

Fluid passing between central chamber 82 and upper chamber 90 is throttled bythrottlevalve 74, as previously described. The position ofthrottle valve 74 with respect to seat 94 and the consequent amount of throttling is determined by the pressure differential between upper chamber 90 and lower chamber84.

The fluid passes through orifice 80 into lower chamber 84 and passage 86. The fluid is prevented from proceeding furthersince sealing member66 is blocking passage 68. Thus, fluid pressure builds up on the lower side of balance piston 72. Such fluid pressure builds up to a predetermined level, whereupon the force acting on diaphragm 60 overcomes the force exerted thereon pry spring 64. Sealing member 66 opens passage 68 allowing fluid to pass therethrough and back into pump inlet conduit 20.

Thus, pressure regulator assembly 38 controls the pressure level acting on the lower side of balance piston 74. Such pressure can be manually adjusted byturning screw 62 and is typically adjusted to approximately midway between the cut in and cut-out pressure of pressure switch 18 (i.e;, pressure switch setting of 30 to 50 p.s.i.g., regulator set at 40 p.s.i.g.).

Valve member assembly 36 continues to control the flow offluid into the system as long as service outlet faucet 30 is open. Once faucet 30 is closed, the pressure in the piping system gradually builds upto a point where it exceeds the pilot pressure acting on balance piston 72. At this point, valve member assembly 36 moves downwardly. It should be noted thatthe rate of increase of the pressure in the piping system and accumulator diminishes asthrottlevalve 74 approaches seat 94 due to its increased throttling ofthe fluid flow into upper chamber 90. This permits motor 12 and pump 1 otto run for longer periods of time and prevents the deleterious on-offcycling of motor 12 and pump 10.

The pressure in upper chamber90 (and in the piping system) gradually increases to a point where it closes throttle valve 74completely, as shown in Figure 6. At this point, the pressure in central chamber 82 isgreaterthanthatin upper chamber90, thereby keeping flow regulator/check valve 98 in its upper position wherein it allows fluid flow; as previously described. The fluid flowing past check valve 98 and into upper chamber 90 serves to refill accumuiator 16.The resiliency of flow regulator/check valve 98 serves to maintain relatively constant the filling time of accumulator 16, regardless of the differential between the pump pressure and the system pressure. Thegreaterthe pressure differential, the more valve 98 deforms into the aforementioned radial grooves 204 so as to prevent increased flow therethrough caused by the greater pressure differential.

Once accumulator 16 is refilled the pressure in the piping systems reaches the cut-off level of pressure switch 18, which turns off motor 12 and pump 10.

Check valve 98 then contacts seat 100 to prevent backflowfrom upper chamber 90 into central chamber 82. The system is then in the position of Figure 4 and ready to begin another cycle.

The control valve assembly 216 of the first embodi mentofthe invention shown in Figure 7 has the same numbered parts as does the control valve assembly 14 of U.S. Patent No.4,165,951 (as shown in Figures 1 to 6 herein), unless otherwise described, noted or shown herein.

The first embodiment solves the problem of disposing of the back pressure regulator flow by the use of biasing spring 206 to load the throttle valve in the closed position. The effect of biasing spring 206 isto require the pressure in chamber 84to be greaterthan that in passage 46 to balance the forces acting on slidable valve member assembly 36. As long as the pressure drop through the back pressure regulator is low enough, the flow through orifice 80 of balance piston 72 can be caused to flow through back pressure regulator38 into conduit 24 or 28 which carries the flow out of chamber 90.This techniqueelim- inatesthe need to feed flow backto the suction side of the pump, but it does require that the pressure drop through the pressure control device be at least as great as the effective pressure of biasing spring 206, that is, the spring force divided by the throttle valve area. The additional pressure drop caused by biasing spring 206 can be substantial in contrast to the pressure drop ofthe water pressure control device disclosed by U.S. Patent No.4,165,951.

The control valve assembly 214 of the second em bodiment ofthe invention in Figures 8 to 10 has the same numbered parts as does the control valve assembly 14 of U.S. Patent No.4,165,951 (as shown in Figures 1 to 6 herein), unless otherwise described, noted or shown herein.

A preferred embodiment of the water pumping system according to one version ofthe second embodiment ofthe invention is shown diagrammatically in Figures 8a and 8b comprise control valve assembly 214 ofthe type (14) disclosed in U.S. Patent No. 4,165,951 connected to water pump 10(not shown) via supply pipe 110 and connected to a water distribution system (not shown - e.g., faucet 30) via discharge pipe 120. (Pressure gage 182 is screwed into threaded passageway 56 of access plug 52). The discharge system can contain water accumulator tank 6 and pressure actuated switch 18 to control water pump 10. Back pressure regulator assembly38 (i.e., BPR) of pressure control device 214contains outlet 50 with outlet conduit 122 connected to throat section 222OfVenturi 130.High pressure inlet 224 of Venturi 130 is connected to pressure control valve inlet conduit 110 via branch conduit 140 feeding flow regulator 150 and branch conduit 228. Discharge or outlet 226 of Venturi 130 is connected to discharge 120 of pressure control valve 1 4via conduit 160. Orifice 80 is located in balance piston 72.

The operation of this version of the second embodimentofthe improved pressure control ofthe invention is best described bythefollowing example: Pressure control valve 214 is supplied with water by pump 10 ata pressure of,forexample, 60 p.s.i.g. (see pressure gage 198). Back pressure regulator assembly 38 is adjusted to maintain a pressure of, for example, 50 p.s.i.g. (see pressure gage 194) in chamber 84, such that slidablevalve member assembly 36 is balanced if the pressure in passage 46 is also 50 p.s.i.g. (see pressure gage 202).Since Venturi 130 is connected at its inlet (224) to a source of pressure at 60 p.s.i.g. (see pressure gage 198), and is connected via its outlet (226) to a pressure source at 50 p.s.i.g., (see pressure gage 202), flow is induced through flow regulator 150 and Venturi 130 in the direction shown. In the example given, flow regulator 150 would control theflowfrom line 1 lOvia line 140 at a rate of 4 gpm, in the process dropping the flow pressure to 55 p.s.i.g. (see pressure gage 196) atthe inlet (224) to the nozzle of Venturi 130. Venturi 130, which is supplied via line 228 with 4 gpm at 55 p.s.i.g., can aspirate about 1 gpm at45 p.s.i.g. via line 122 when discharging via !ine 160 into a pressure of 50 p.s.i.g. in line 120.Thus, in the example given, back pressure regulator38 (see Figure 8b) can operatewith a pressure drop of 5 p.s.i.g. at 1 gum while maintainingthe pressure jn chamber 84 at 50 p.s.i.g., and discharge into the low-pressure side (iine 120) of pressure control device 214.

The upper portion of slidable valve member assembly 36 can also contain a flow control device (see 106, etc.), as disclosed in U.S. Patent No.

4,165,951 and Figures 1 to 6 herein. In the case ofthe present invention,theflow passing through back pressure regulator assembly 38 and Venturi 130 would be added to the flow passing through the flow control check valve assembly.

In a deep well application, it is usually not necessaryto provide a check valve to prevent backflow fromthe distribution system conduitl20topump conduit 110, since a "footvalve" (not shown) is usually provided upstream of the pump. In the eventthat it is necessary to prevent backflowfrom conduit 120 to conduit 110, however, this can be accomplished by installing a checkvalve (not shown) in conduit 160, or in conduit 120 downstream of the junction between conduit 120 and 160, or in conduit 110 up streamofthejunction between conduitll0and con- duitl40.

A most preferred configuration of anotherversion of the second embodiment of the invention is shown in Figures 9a and 9b. Concerning the regulator and Venturi device (232) shown in Figures 9a and 9b,the Venturi and flow regulator have been combined into a single housing (200). Housing 200 contains inlet chamber 210 separated from Venturi inlet 220 by shoulder 230. Shoulder 230 supports elastomeric disc 240 which operates as a flow regulator in the mannerofa "Dole" regulator, which is well known to those skilled in the art. Dole regulator240 is deformable. Orifice 234 of Dole regulator240 serves as the nozzleofVenturi236,forming a jet directed atthroat 250 of Venturi 236. Dole regulator240 acts as a jet pump oraspirator.Conduit 122connects inlet chamber 220 of Venturi 236 with the outlet 50 of back pressure regulator 38. Other flow regulator devices which operate in the manner of a Dole regulator by restricting the flow orifice as the pressure differential increases can be substituted in place of the Dole regulator.

Afurtherversion of the second embodiment of the invention is shown in Figures 10a and 1 Ob. Aprefer- red embodiment of the junction between supply conduit 110 and water conduit 140, the latter leading to flow regulator 150 or the "Dole" regulator, is shown in Figures 10a and 10b. Inlet passage 40 of pressure control valve assembly 214 is fitted with pipe stub 170 having closed end 176 and orifice 180 directed so asto face the incoming flow carried by conduit 110.

At high rates of flowthrough conduit 110 when the inlet pressure to the control valve may be low due to a fall-off in pump delivery pressure, this arrange- ment wiil recover a portion of the dynamic head in the incoming flow, converting itto static pressure in conduit 140, thereby providing high supply pressure to the Venturi assembly.

The foregoing improvements described underthe second embodimentofthe invention permit a pressure control valve as described in U.S. Patent No.

4,165,951 to operate without feeding flow from its back-pressure regulator back to the suction-side of the pump and without requiring the additional pressure drop caused buy a biasing spring. This will enable such a pressure control valve to be located re motely from the water pump, as in the case of a submerged deep well pump.

The pertinent parts of U.S. Patent No.4,165,951, inventors: Friedman and Becker, "Water Pressure Booster System And Control Valve Therefor", are incorporated herein by reference.

Claims (13)

1. In a water pressure booster system for regulating water pressure in a piping system having pumping means connected to a water supply, the improved means for controlling water flow into the piping system comprising: (a) a housing having an inlet passage connected to an outlet of said pumping means and an outlet connected said piping system; (b) a valve memberslidably contained within said housing,saidvalve membercomprising a throttle valve, and a balance piston connected to said throttle valve, said balance piston having an orifice therethrough to allow passage ofwaterfrom a first side of said balance piston to a second side thereof; (c) biasing meansadaptedto loansaidthrottle valve in a closed position; and (d) pressure regulating means to regulate the pressure acting on said second side of said balance piston, said pressure regulating means being interconnected between said second side of said piston and an inlet of said pumping means.

2. The improved water pressure booster system of Claim 1 wherein said biasing means is a biasing spring, wherein said housing has an inlet chamber and an outlet chamber, wherein said biasing spring is positioned in said outlet chamber between said inlet and said outlet and in workable contact with said throttle valve, wherein said water pressure boo ster system includes a combinaiton flow regulator/ check valve means disposed in a passage bypassing said throttle valve to permit a reduced flow of water into said piping system when said throttle valve is closed and said pumping means is operating.

3. Valve comprising: (a) a housing having an inlet passage and an outlet passage; (b) a valve member slidably contained within said housing, having a central shaft with a throttle valve portion on a first end of said central shaft and a balance piston on a second end thereof, said valve member located such that said inlet passage is intermediate saidthrottlevalve and said balance piston; (c) biasing means adapted to load said throttle valve in a closed position; and (d) meansforestablishing a regulated pressure acting on said balance piston such that the movement of the slidable valve member is controlled by the pressure differential between the regulated pressure and a pressure atthe outlet passage.

4. The valve of Claim 3 wherein the throttle valve portion has an outer surface in the shape ofatrunca- ted paraboloid such thatthe amountoffluidthrott- ling is inversely proportional to the distance between said throttling valve and its seat.

5. In a water pressure booster system for regulating water pressure in a piping system having pumping means connected to a water supply, the means for controlling water flow into the piping system comprising: (a) a housing having an inlet passage connected to an outlet of said pumping means and a first outlet connected to said piping system; (b) a valve membercontained within said housing without biasing means so as to be freely slidble therein, said valve member comprising a throttle valve and a balance piston connected to said throttle valve; (c) pressure regulating means to regulate the pressure acting on the side of said balance piston facing away from said throttle valve, said pressure regulating means being interconnected between said side of said piston and a second outlet in said housing,the improvement comprising:: (i) flow regulating means having an inlet connected to said connection between said outlet of said pumping means and said inlet passage of said housing, said flow regulating means also having an outlet; (ii) venturi means having an inlet, a throat and an outlet, said inlet of said venturi means being connected to said outlet of said flow regulating means, said outlet of said venturi means being connected to said piping system which is connected to said first outlet of said housing, and the lowest pressure point in said venturi means being connected to said second outlet in said housing.

6. The improved water pressure booster system of Claim 5 wherein a deformable disc having a central passageway is perpendicularly located in the mouth of said venturi means to the longitudinal central axis of said venturi means and the connection to said outlet in said housing is located between said deformable disc and said throat ofsaid-venturi means.

7. The improved water pressure booster system of Claim 6 wherein the diameter of said throttlevalve is equal to that of said balance piston such thatthe force exerted on said valve member ofthewateren- tering the housing does not move said valve member.

8. The improved water pressure booster system of Claim 6 wherein said water pressure booster system includes a flow regulator means disposed in a passage bypassing said throttle valve to permit a reduced flow of water into said piping system when said throttlevalve is closed and said pumping means is operating and preventing flow from said piping system back through said passage when said pumping means stops.

9. Valve comprising: (a) a housing having an inlet passage and an outlet passage; (b) a valve member contained within said housing without biasing means so as to be freely slidable therein, said valve member having a central shaft with athrottlevalve portion on afirstend ofsaidcen- tral shaft and a balance piston on a second end, said valve member located such that each inlet passage is intermediate said throttle valve apd said balance piston; (c) means for establishing a regulated pressure acting on said balance piston such thatthe movement of the slidable valve member is controlled by the pressure differential between the regulated pressure and a pressure atthe outlet passage;; (d) flow regulator means located in said throttle valve portion and controlling fluid flow between said inlet passage and said outlet passage when said throttle valve portion is closed, said flow control valve means allowing fluid flow when said inletpressure is greaterthan said outlet pressure and preventing fluid flow when the outlet pressure exceeds the inlet pressure; and (e) scoop means located in said inlet passage with its opening oriented and adapted to face into the direction offlow in said inlet passage.

10. The improved water pressure booster system of Claim 9 wherein said scoop means comprises a tube protruding into said inlet passage, the inner end of said tube being closed, the outer end of said tube being open, and a side opening within said inletpassage, said side opening facing away from said housing.

11. A control valve according to claim 3 or claim 9 substantially as hereinbefore described with reference to and as illustrated in Figures 7a and 7b, Figures 8a and 8b, Figures 9a and 9b, Figures 1 Oa and 1 Ob of the accompanying drawings.

12. A water pressure boosting system comprising a control valve according to claim 11.

13. Awater pressure boosting system according to Claim 1 or claim 5 substantially as hereinbefore described.