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WO1999023544A1 - Soupape pilotee - Google Patents

Soupape pilotee Download PDF

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Publication number
WO1999023544A1
WO1999023544A1 PCT/GB1998/003278 GB9803278W WO9923544A1 WO 1999023544 A1 WO1999023544 A1 WO 1999023544A1 GB 9803278 W GB9803278 W GB 9803278W WO 9923544 A1 WO9923544 A1 WO 9923544A1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
pilot valve
prv
outlet
pilot
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/GB1998/003278
Other languages
English (en)
Inventor
John Henry May
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FLUID CONTROLS UK Ltd
Original Assignee
FLUID CONTROLS UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by FLUID CONTROLS UK Ltd filed Critical FLUID CONTROLS UK Ltd
Priority to AU10398/99A priority Critical patent/AU1039899A/en
Publication of WO1999023544A1 publication Critical patent/WO1999023544A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D16/00—Control of fluid pressure
    • G05D16/14—Control of fluid pressure with auxiliary non-electric power
    • G05D16/16—Control of fluid pressure with auxiliary non-electric power derived from the controlled fluid
    • G05D16/163—Control of fluid pressure with auxiliary non-electric power derived from the controlled fluid using membranes within the main valve

Definitions

  • This invention relates to a pilot valve for controlling operation of a hydraulically- actuated pressure reducing valve (PRV).
  • PRV hydraulically- actuated pressure reducing valve
  • the invention also relates to a PRV system including a pilot valve and a PRV.
  • PRVs are designed to control to a pre-set constant outlet pressure irrespective of flow rate and the inlet pressure.
  • Self regulation is achieved with a pilot loop surrounding the main valve.
  • This externally mounted loop constructed of small bore pipe is connected from the inlet of the PRV to a chamber in the main valve referred to as the control space and then usually through a tee connection to the outlet of the valve.
  • a restriction usually of the form of an orifice plate and between the control space and the outlet is a pilot valve.
  • a typical prior art pilot valve has a simple spring loaded valve arrangement whereby a spring is caused to act against a diaphragm plate fixed to a diaphragm.
  • a rigid connection is made between the diaphragm plate and a yoke.
  • the bottom of the yoke holds a seat onto which water from the upstream pilot loop pipe work is discharged through a nozzle.
  • the water then proceeds to the outlet of the main valve such that the total pressure acting beneath the pilot diaphragm is equivalent to the outlet pressure.
  • the position of the main valve throttling element is determined by the volume of water in the control space, which is governed by the pilot valve so as to maintain a constant outlet pressure.
  • Adjustment of the outlet pressure setting is achieved by altering the compressive force exerted by the spring in the pilot valve. This is achieved by turning an adjusting screw.
  • the spring is very strong and turning the screw therefore requires a lot of force, necessitating the use of a tool such as a spanner or wrench. This makes it difficult to set the PRV to a precise pressure.
  • the pilot valve After the pilot valve has been set to control to a particular outlet pressure the summation of forces resulting from those acting across the main valve elements and those occurring in the pilot valve are such that with a steady flow through the main valve, the pilot valve seat assumes a fixed position away from the nozzle and a small flow continually passes through the pilot loop.
  • This continuous process enables the PRV to regulate to a set outlet pressure for changes in flow rate and the inlet pressure. It is desirable to be able to adjust this outlet pressure, so that it can be set to an appropriate value according to the expected supply and demand.
  • the inventor has realised that irrespective of the set pressure as determined by the compressive force of the pilot valve's spring setting, the balance point position, that is the distance between the pilot valve's nozzle and the seat, is fixed. At the balance point position, the hydraulic loss coefficient also remains fixed hence for any hydraulically actuated PRV of the style described there is a particular balance point loss coefficient. The inventor has used this fact to design a pilot valve that allows the outlet pressure to be adjusted very easily.
  • valve It is desirable to cause the valve to alter the outlet pressure as a function of flow rate, increasing pressure as the flow increases and reducing pressure as the flow rate diminishes.
  • peak demand typically occurring around breakfast time and the lowest demand occurring during the early hours of the morning.
  • Pipe friction losses governed by the flow rate lead to a loss of pressure and the pressure downstream of the PRV must be set at a sufficient level to overcome pressure losses between the PRV and the consumer at a peak flow, when the greatest friction losses occur.
  • the pressure as set by the PRV is greater than required at all flows below the peak flow and therefore leakage rates and susceptibility to bursts is greater than need be.
  • pressures could fall below minimum requirements to ensure a satisfactory supply of water to all consumers.
  • the use of an additional chamber in the pilot valve enables the spring force to be biased, thereby altering the outlet pressure setting without manually adjusting the pilot valve spring.
  • the chamber may be positioned between the pilot valve spring and the diaphragm or rigidly connected beneath the pilot valve seat. Various methods are employed.
  • One electronic control method uses miniature solenoid valves which are arranged either to pulse small volumes of water taken from an upstream pressure connection into the chamber to increase the outlet pressure or to reduce the outlet pressure by discharging discrete volumes from the chamber to atmosphere.
  • This method requires as a minimum a means of measuring the outlet pressure at frequent intervals and software to process pressure data to effect control to a time profile. More complex forms of control can be achieved with the addition of data from a flow meter such as a flow modulating duty.
  • a purely hydraulic solution can be achieved by using pressure signals from a differential type of flow meter inserted in the water mains either upstream or downstream of the PRV.
  • the pressure signal of the low pressure tapping is so arranged to act on an isolated pilot diaphragm.
  • a further limitation of the hydraulic approach is that it can only follow a flow squared outlet pressure relationship by virtue of the physical nature of the behaviour of differential pressures with flow rate.
  • a pilot valve for controlling operation of a hydraulically-actuated pressure reducing valve (PRV), the pilot valve including a housing, a first valve member mounted in the housing for movement relative thereto in response to the outlet pressure of the PRV, a second valve member mounted in the housing for movement relative thereto, and an adjuster for adjusting the position of the second valve member relative to the housing, the pilot valve being designed to control operation of the PRV according to the relative positions of the first and second valve members.
  • PRV hydraulically-actuated pressure reducing valve
  • the adjuster acts on the second valve member, allowing its position to be adjusted relative to the housing, only a small adjusting force is needed.
  • the outlet pressure of the PRV can therefore be adjusted very easily and precisely.
  • said first valve member includes a seat and said second valve includes a fluid flow nozzle for discharging fluid onto said seat, the rate of flow of fluid through said nozzle depending in use on the separation of the nozzle and the seat.
  • said fluid flow nozzle includes a moveable nozzle vent.
  • the pilot valve includes a control member connected to the nozzle vent for controlling movement thereof.
  • the pilot valve includes a manually operable adjuster connected to the control member.
  • the pilot valve includes an actuator connected to the control member. This allows automatic adjustment of the outlet pressure, thereby providing for the possibility of a flow modulated duty.
  • said first valve member includes a valve stem and said second valve includes a valve body including an inlet vent, an outlet vent and an inlet/ outlet vent, the flow of fluid through said inlet/ outlet vent depending in use on the relative positions of the valve body and the valve stem.
  • the pilot valve includes a control member connected to the valve body for controlling movement thereof.
  • the pilot valve includes a manually operable adjuster connected to the control member.
  • the pilot valve includes an actuator connected to the control member.
  • said adjuster includes a rotatable adjusting member having a spiral- shaped guide member and said control member includes a leg member engaging said guide member, the arrangement being such that rotating said adjusting member adjusts the position of said second valve member.
  • the full range of outlet pressures can then be selected with only a single turn of the adjuster.
  • said guide member lies within a substantially hemispherical concave surface.
  • a pressure reducing system including a PRV and a pilot valve, wherein said actuator is connected to the PRV and is designed to adjust the position of the second valve member according to the operational state of the PRV.
  • the outlet pressure can then be adjusted as a function of the flow rate, allowing lower outlet pressures at times of low demand whilst ensuring adequate pressure for consumers at times of peak demand.
  • said actuator is connected hydraulically to the PRV.
  • the PRV includes a valve stem and a cam member connected to said valve stem for movement therewith, and the actuator is connected to a cam follower that engages said cam member.
  • the cam member has a plurality of cam profiles for selective engagement by the cam follower, allowing different flow modulated duties to be selected as appropriate.
  • a pilot valve for controlling operation of a hydraulically-actuated pressure reducing valve (PRV) in response to the outlet pressure of the PRV, the pilot valve including a chamber for connection to the outlet of the PRV, the chamber being defined by a plurality of surface elements including at least one resiliently-biassed surface element that is moveable to adjust the volume of the chamber in response to the outlet pressure of the PRV, and a valve member for controlling operation of the PRV by controlling the flow of fluid to or from a control space in said PRV, said valve member being operably connected to the resiliently-biassed surface element for control thereby, said pilot valve having a balanced condition in which the flow of fluid to or from the control space of the PRV is zero, the pilot valve including adjusting means for adjusting the pilot valve such that a balanced condition may be reached at different outlet pressures, characterised
  • the invention provides a pilot valve wherein the position of the seat and therefore the spring force is changed by altering the position at which the balance point position occurs.
  • the balance point may be adjusted through a mechanical, hydraulic, magnetic, electronic arrangement or any combination thereof.
  • the loss coefficient of the pilot is temporarily caused to increase by the introduction of a shroud which partially covers the gap between the nozzle and the seat the result is that in returning to the balance point position the seat will move away from the nozzle and therefore the spring force will be reduced and the outlet pressure will be lower. The same effect would also occur if the nozzle was lowered.
  • the device may be so arranged as to be connected to a differential control device such as a Pitot tube or a cascaded venturi, enabling a modulation duty to be provided.
  • Fig. 1 is a side cross-section through a prior art pilot valve
  • Fig. 2 is a side cross-section through a pressure reducing valve system, including a main valve and a pilot valve, according to a first embodiment of the invention
  • Fig. 2a is a side cross-section, showing an enlarged detail of the pilot valve shown in Fig. 2;
  • Fig. 2b is an enlarged view of an end part of the pilot valve shown in Fig. 2;
  • Fig. 3 is a side cross-section through a pressure reducing valve system, including a main valve with a turret housing and a pilot valve, according to a second embodiment of the invention
  • Fig. 3a is a plan view of a top part of the turret housing shown in Fig. 3;
  • Figs. 4 and 5 are side cross-sections through the pressure reducing valve system shown in Fig. 3, showing the system at two different water flow rates;
  • Fig. 6 is a side cross-section through a pressure reducing valve system, including a main valve with a turret housing and a pilot valve, according to a third embodiment of the invention
  • Fig. 7 is a side cross-section through a pressure reducing valve system, including a main valve and a three-way pilot valve, according to a fourth embodiment of the invention.
  • Figs. 8a, 8b, 8c and 8d are side cross-sections through a pilot valve according to a fifth embodiment of the invention, showing the valve at different balance point settings;
  • Figs. 9a, 9b, 9c and 9d are cross-sections on line IX-IX through the pilot valve as shown in Figs. 8a, 8b, 8c and 8d;
  • Fig. 10 is a side cross-section through a pilot valve according to a sixth embodiment of the invention.
  • Fig. 11 is a cross-section on line XI-XI through the pilot valve shown in Fig. 10.
  • a typical prior art pilot valve is shown in Fig. 1.
  • the pilot valve is of a simple spring loaded valve arrangement whereby a spring 2 is caused to act against a diaphragm plate 4 fixed to a diaphragm 6.
  • a rigid connection is made between the diaphragm plate 4 and a yoke 8.
  • the bottom of the yoke holds a seat 10 onto which water from the upstream pilot loop pipe work is discharged through a nozzle 12.
  • the water then proceeds to the outlet of the main valve such that the total pressure acting beneath the pilot diaphragm 6 is equivalent to the outlet pressure.
  • the position of the main valve throttling element is determined by the volume of water in the control space.
  • Adjustment of the outlet pressure setting is achieved by altering the compressive force exerted by the spring in the pilot valve. This is achieved by turning an adjusting screw 13.
  • the spring 2 is very strong and turning the screw therefore requires a lot of force, necessitating the use of a tool such as a spanner or wrench. This makes it difficult to set the PRV to a precise pressure.
  • a pressure reducing valve system is shown in Fig. 2 and includes a main pressure reducing valve (PRV) 14 and a pilot valve 16.
  • the main PRV 14 is conventional and includes an inlet 18 and an outlet 20 which are connected to one another through a valve seat 22, and a valve body 24 that is mounted on a valve stem 26 for movement towards and away from the valve seat 22.
  • the valve body 24 is mounted in a diaphragm 28, above which there is a biassing spring 30 and a chamber known as the control space 32.
  • the position of the valve body 24 and hence the pressure reduction produced by the PRV 14 is determined by the volume of water in the control space 32.
  • the inlet 18 is connected to the control space 32 via a first small bore pipe 34, an orifice plate 36, a T-junction 38, a control valve 40 and a second pipe 42.
  • a third pipe 44 extends from the T-junction 38 to the pilot valve 16 and a fourth pipe 45 extends from pilot valve 16 to the outlet 20.
  • Operation of the PRV is conventional, the valve opening when demand increases and closing when demand decreases, so as to maintain a substantially constant pressure at the outlet 20. This outlet pressure is determined by the setting of the pilot valve 16.
  • the pilot valve 16 includes a housing 46, which is divided by a flexible diaphragm 48 into a dry chamber 50 and a wet chamber 52.
  • the diaphragm 48 may be a rolling diaphragm as shown in the drawings or any other suitable type.
  • a diaphragm plate 54 is pressed against the diaphragm 48 by means of a spring 56, located in the dry chamber 50.
  • a yoke 58 located in the wet chamber 52, is connected to the diaphragm plate by a bolt 60. At its remote end, the yoke 58 carries a seat 62.
  • a water inlet nozzle 64 located in the wet chamber 52 is connected to the third pipe 44 and is positioned to discharge a stream of water along the longitudinal axis of the valve towards the seat 62. Water leaves the pilot valve through an outlet vent 66 provided in a wall of the wet chamber 52.
  • valve described above does not include a screw for adjusting the force exerted on the diaphragm plate 54 by the spring 56.
  • the valve differs from the conventional pilot valve shown in Fig. 1 in that the water inlet nozzle 64 is modified to include an adjustable nozzle vent 68.
  • This nozzle vent 68 which is shown more clearly in Fig. 2a, comprises a cylindrical member that is mounted in the end of the inlet nozzle for sliding movement in the direction of the valve's longitudinal axis.
  • a plurality of water flow channels 70 extend through the member parallel to the longitudinal axis. In use, water is discharged through these flow channels 70 towards the seat 62.
  • a control rod 72 is connected to the nozzle vent 68 and extends through the seat 62 and a bore 74 in the end of the valve housing 46, the bore being sealed to prevent leakage by means of an O-ring 76.
  • the free end of the rod is provided with a screw thread that engages a control knob 78 mounted on the end of the housing 46. Turning the knob 78 drives the nozzle vent 68 backwards and forwards along the axis of the pilot valve thereby adjusting the effective position of the inlet nozzle 64.
  • the position of the knob 78 is indicated by a gauge dial 80 mounted on the end of the housing 46 (Fig. 2b).
  • the position of the seat 62 is determined by the pressure in the wet chamber 52 acting on the diaphragm 48, which is equal to the pressure at the outlet of the PRV 14.
  • the rate of flow of water through the nozzle 64 in turn depends on the position of the seat 62 relative to the end of the nozzle vent 68.
  • the outlet pressure can be adjusted be turning the knob 78 to alter the position of the nozzle vent 68 relative to the inlet nozzle 64.
  • the distance between the end of the inlet nozzle 64 and the seat 62 is always the same. Therefore, if the knob 78 is turned in a direction to move the inlet nozzle 68 towards the seat 62, water will flow into the control space 32, closing the PRV 14 and reducing the outlet pressure.
  • the pilot valve will then start to open and equilibrium will not be restored until the diaphragm plate 54 has moved sufficiently to restore the original separation between the end of the inlet nozzle 68 and the seat 62, at which point water will cease flowing into the control space.
  • the spring 56 will then be less compressed than previously and the outlet pressure will be lower.
  • FIG. 3 A second embodiment of the pilot valve is shown in Fig. 3, in which the control knob is replaced by a hydraulic linear actuator 82.
  • the linear actuator 82 is connected directly to the control rod 72 and is operable to control the position of the nozzle vent 68. Because only a small force is needed to adjust the position of the nozzle vent 68, only a small actuator is required.
  • the first linear actuator 82 is connected through a hydraulic line 84 to a second linear actuator 86, which is connected to a cam follower 88.
  • a hydraulic adjuster 90 is provided to adjust the volume of the hydraulic circuit, so allowing the base outlet pressure to be adjusted.
  • the cam follower 88 engages a profiled cam member 92 that is mounted on an extension shaft 94, which is connected directly to the main shaft 26 of the PRV 14.
  • the vertical position of the cam member 92 relative to the extension shaft 94 can be adjusted using an adjuster 96 that is mounted for rotation relative to the extension shaft 94 and has a screw thread engaging a corresponding thread on the inner surface of the cam member 92.
  • the extension shaft 94 is mounted for vertical movement with the main shaft 26 and the cam member 92 is profiled to convert this vertical movement into horizontal movement of the cam follower 88.
  • the position of the nozzle vent 68 is therefore related directly to the position of the main shaft 26, which in turn depends on the flow rate through the PRV. This allows the outlet pressure to be modulated according to the demand or any particular duty required of the valve.
  • the second actuator 86 is mounted in a turret housing 98, which is attached to the housing of the PRV 14 through a rotary coupling 100 that allows the turret housing 98 to be rotated freely relative to the PRV 14.
  • the cam member 92 is provided with a plurality of different cam profiles, which are angularly distributed around its circumference. Rotating the turret housing 98 rotates the cam follower 88 relative to the cam member 92, allowing the appropriate cam profile to be selected.
  • a scale 102 for any particular duty may be provided on the top of the turret housing 98, to indicate the cam/cam follower relationship, by reference to a pointer 104 connected to the housing of the PRV 14.
  • the profile of the cam member 92 may, for example, consist of an upper portion 106 that is entirely vertical and a lower portion 108 that is curved exponentially, the thickness of the cam increasing towards its lower end.
  • the increase in thickness may vary around the circumference of the cam member 92 from zero to a maximum value. Therefore, for a flow modulating duty, the profile seen from above of the lower end of the cam member will resemble a spiral, as shown in Fig. 3a. This allows the degree of modulation to be varied by rotating the turret housing 98 from zero (no modulation) to a maximum modulation effect.
  • FIG. 3 illustrates a situation when demand is low.
  • the PRV 14 is nearly closed to maintain a constant outlet pressure and the cam follower 88 engages the upper portion 106 of the cam member 92, which is not profiled.
  • the position of the nozzle vent 68 is therefore unaffected and the outlet pressure is not modulated.
  • the PRV 14 When demand increases, the PRV 14 opens as shown in Fig. 4 and the main shaft 26 rises. The cam follower 88 then engages the lower portion 108 of the cam member 92 and is activated by its curved profile. The linear actuator 82 thus drives the nozzle vent 68 in a direction away from the seat 62, opening the PRV and increasing the outlet pressure. As demand increases further, the PRV 14 opens more as shown in Fig. 5 and the cam follower 88 engages the thicker part of the cam member 92 towards its lower end. The linear actuator 82 thus drives the nozzle vent 68 further away from the seat 62, opening the PRV more and increasing the outlet pressure again. The system thus provides a duty cycle that is modulated according to demand.
  • the cam member 92 is profiled to provide a relatively simple relationship between outlet pressure and demand, the outlet pressure increasing exponentially with demand when demand exceeds a certain predetermined level.
  • more complicated relationships can be provided, simply by adjusting the profile of the cam member.
  • the profile can thus be designed to provided a customised duty cycle that is matched to the known demand characteristics of the water supply.
  • Fig. 6 illustrates a modified form of the system, in which the hydraulic adjuster is omitted and instead a conventional screw adjuster 110 is provided for adjusting the compression of the spring 56.
  • This adjuster 110 can be used to adjust the base outlet pressure of the system (i.e. the outlet pressure at no modulation).
  • Fig. 7 illustrates a three-way pilot valve 112 that has been modified in a similar manner to the pilot valves described above.
  • the pilot valve includes a cylindrical housing 114, which is divided by a transverse wall 116 into an upper part 118 and a lower part 120.
  • a diaphragm 122 extends across the end of the upper part 118, defining an upper chamber 124 between the wall 116 and the diaphragm 122.
  • the upper chamber 124 is connected through a port 126 and a fluid flow line 128 to the downstream side of the PRV 14 and the pressure within the chamber 124 is therefore equal to the outlet pressure of the PRV.
  • a diaphragm plate 130 is pressed against the upper surface of the diaphragm 122 by a compression spring 132, which is constrained within a cap 134, bolted to the upper end of the housing 114. The force exerted by the spring 132 balances the pressure in the chamber 124.
  • a valve stem 136 is attached to the diaphragm plate 130 and extends downwards through the diaphragm 122 into the lower part 120 of the housing 114.
  • the valve stem has a sliding fit within an axial bore in a valve body 138, which itself has a sliding fit within the lower part 120 of the cylindrical housing 114.
  • O-rings 140 are provided to prevent leakage between the valve stem 136 and the valve body 138.
  • a pair of matched compression springs may be provided above and below the valve body 138, to bias the valve body towards a central position within the lower part of the housing 114. Those springs can be relatively weak.
  • the lower part 120 of the housing 114 is closed by an end wall 142.
  • a control rod 144 extends axially through the end wall and engages the lower end of the valve body 138.
  • the control rod 144 is provided with a screw thread which engages a complementary thread on an adjuster knob 146 mounted on the lower end of the housing 114. Turning the knob 146 adjusts the axial position of the valve body 138 within the housing 114.
  • the valve stem 136 has a central portion 148 of reduced diameter.
  • the valve body 138 is provided at a corresponding position with a fluid inlet/outlet port 150, which is connected by a first fluid flow line 152 to the control space 32 in the PRV 14.
  • On the opposite side of the valve body 138 two ports are provided, one slightly above and the other slightly below the fluid inlet/outlet port 150.
  • the upper port comprises a fluid inlet port 153 and is connected by a second fluid flow line 154 to the upstream side of the PRV 14.
  • the lower port comprises an outlet port 156 and is connected by a drain line 158 to the atmosphere.
  • the ports 150, 153, 156 are so positioned that when the central portion 148 of the valve stem 136 is located centrally between the inlet port 153 and the outlet port 156 there is no fluid flow connection between any of the three ports. Fluid cannot then flow into or out of the control space and this is therefore the equilibrium position of the pilot valve. However, if the valve stem 136 is displaced upwards from the equilibrium position, the inlet port 153 is connected to the inlet/outlet port 150 via the central portion 148 of the valve stem, which allows water to flow into the control space 32 from the upstream side of the PRV 14. Conversely, if the valve stem 136 is displaced downwards from the equilibrium position, the inlet outlet port 150 is connected to the outlet port 156 allowing water to flow out of the control space 32 to atmosphere.
  • the position of the valve stem 136 is determined by the pressure in the upper chamber 124, i.e. the outlet pressure of the PRV.
  • the central portion 148 of the valve stem 136 is located centrally between the inlet port 153 and the outlet port 156. Water cannot then flow into or out of the control space 32 and the position of the PRV 14 is therefore fixed.
  • valve stem 136 will be driven downwards by the spring 132, thereby establishing a fluid flow connection between the inlet/outlet port 150 and the outlet port 156. Water will therefore flow out of the control space 32 and the PRV 14 will open, restoring the outlet pressure to the predetermined level.
  • the outlet pressure can be adjusted using the adjuster knob 146. Turning the knob one way will push the valve body upwards. Equilibrium will then be reached with the spring 132 in a more compressed state: i.e. at a higher outlet pressure. Turning the knob the other way will allow the valve body to move downwards and equilibrium will then be reached with the spring 132 in a less compressed state: i.e. at a lower outlet pressure.
  • the position of the valve body can be adjusted using a hydraulic actuator similar to that shown in Fig. 3 or any other suitable actuator, for example an electrically or magnetically operated actuator.
  • the actuator can be adjusted automatically to provide outlet pressure modulation, for example using a cam connected to the valve stem of the PRV 14 as shown in Fig. 3 or any other suitable means, for example by sensing the differential pressure and using electronics to control the actuator.
  • Figs. 8a-8d and 9a-9d illustrate a modification of the pilot valve shown in Fig. 2, in which the control knob is replaced by an alternative adjuster mechanism 160.
  • This adjuster mechanism 160 may also be used with the three-way valve 112 shown in Fig.
  • the adjuster mechanism 160 includes a hemi-spherical housing 162 which is mounted by means of a circular plate 164 and a rotatable mounting element 165 on the end of the pilot valve housing 46.
  • the mounting element 165 is designed to allow rotational and axial movement of the hemi-spherical housing 162 relative to the pilot valve housing 46.
  • a spiral slot 166 is cut in the hemi-spherical housing 162.
  • the control rod 72 extends into the hemi-spherical housing 162 through the end of the pilot valve housing 46 and the rotatable mounting element 165.
  • a pivot pin 168 Connected to the free end of the control rod 72 by means of a pivot pin 168 are a pair of legs 170, one of which is shown in broken lines.
  • the legs are connected to one another by gears to rotate in unison about the pivot pin 168, so that both legs always subtend the same angle in relation to the longitudinal axis of the pilot valve.
  • the free end of one of the legs is engaged in the spiral slot 166.
  • a compression spring 172 is mounted on each leg 170 and bears against the inner surface of the hemispherical housing 162 through a thrust plate 174.
  • the position of the nozzle vent 68 is determined by the axial position of the hemi- spherical housing 162 relative to the pilot valve housing 46 and the axial force transmitted to the control rod by the compression springs 172 mounted on the legs 170.
  • the angle of the legs can be adjusted by turning the housing 162 so that the legs 170 pivot inwards or outwards about the pivot pin as guided by the spiral slot 166.
  • the base outlet pressure (the pressure at very low flow rates) can be varied by adjusting the axial position of the hemi-spherical housing 162 relative to the pilot valve housing 46.
  • the advantage of this adjuster mechanism is that the outlet pressure can be varied between its maximum and minimum values by turning the housing through an angle of 360 ° .
  • the base pressure can be adjusted by axial movement of the housing 162. It is a relatively simple matter therefore to provide a linear scale and a gauge dial showing the selected pressure settings.
  • a hydraulic adjuster 176 is provided between the pilot valve 16 and the adjuster mechanism 160.
  • the adjuster mechanism 160 is connected to the pilot valve 16 by means of a rotatable mounting element 177 that permits rotational, but not axial, movement of the adjuster mechanism 160 relative to the pilot valve 16.
  • the hydraulic adjuster 176 acts directly on the control rod 72 and allows the balance point to be controlled automatically, for example using a cam connected to the valve stem of the PRV as shown in Fig. 3, to provide modulated outlet pressures.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Control Of Fluid Pressure (AREA)

Abstract

L'invention porte sur une soupape pilotée (16) destinée à réguler le fonctionnement d'un robinet (14) réducteur de pression (PRV) à commande hydraulique. Cette soupape pilotée comprend un corps (46), un premier élément (62) monté dans le corps et se déplaçant par rapport à celui-ci en réaction à la pression de sortie du PRV, un second élément (68) monté dans le corps et se déplaçant par rapport à celui-ci, et un ajusteur (78) qui ajuste la position du second élément de soupape par rapport au corps. La soupape pilotée (16) est conçue pour réguler le fonctionnement du PRV (14) en fonction des positions relatives des premier et second éléments (62, 68) de soupape.
PCT/GB1998/003278 1997-11-05 1998-11-04 Soupape pilotee Ceased WO1999023544A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU10398/99A AU1039899A (en) 1997-11-05 1998-11-04 Pilot valve

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB9723287.0A GB9723287D0 (en) 1997-11-05 1997-11-05 Balance point modulating pilot
GB9723287.0 1997-11-05

Publications (1)

Publication Number Publication Date
WO1999023544A1 true WO1999023544A1 (fr) 1999-05-14

Family

ID=10821564

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1998/003278 Ceased WO1999023544A1 (fr) 1997-11-05 1998-11-04 Soupape pilotee

Country Status (3)

Country Link
AU (1) AU1039899A (fr)
GB (1) GB9723287D0 (fr)
WO (1) WO1999023544A1 (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2438938A (en) * 2006-03-24 2007-12-12 John Henry May Pilot valve
WO2008114036A1 (fr) * 2007-03-22 2008-09-25 I2O Water Limted Soupape pilote pour détendeur
GB2448086A (en) * 2007-03-26 2008-10-01 John Henry May Pilot valve
GB2450125A (en) * 2007-06-13 2008-12-17 Aquavent Uk Ltd Pressure reducing valve control
WO2009132007A3 (fr) * 2008-04-21 2010-12-02 Emerson Process Management Regulator Technologies, Inc. Corps de soupape à double mécanisme de détection
CN102246112A (zh) * 2008-05-20 2011-11-16 费希尔控制国际公司 用于调节流体流动的装置
US8151822B2 (en) 2007-04-20 2012-04-10 Fisher Controls International Llc Integral overpressure monitoring device
US8240327B2 (en) 2008-04-21 2012-08-14 Emerson Process Management Regulator Technologies, Inc. Pressure loaded service regulator with pressure balanced trim
US8281803B2 (en) 2008-04-18 2012-10-09 Fisher Controls International Llc Balanced port housing with integrated flow conditioning
US9493931B2 (en) 2008-12-30 2016-11-15 I20 Water Limited Mains water supply processing
US9644349B2 (en) 2007-01-24 2017-05-09 I2O Water Limited Controller and control system for a pressure reducing valve
WO2019098867A1 (fr) * 2017-11-16 2019-05-23 Gas Teh Ltd Régulateur de pression de gaz axiale à action directe de pression de sortie et d'entrée

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US3896843A (en) * 1973-05-11 1975-07-29 Parker Hannifin Corp Pilot valve for controlling a fluid pressure operated valve
US5411053A (en) * 1994-07-01 1995-05-02 Daniel A. Holt Fluid pressure regulator
WO1997038363A1 (fr) * 1996-04-04 1997-10-16 The Curators Of The University Of Missouri Servosoupape ultrarapide a basse puissance d'actionnement

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US3669143A (en) * 1969-11-06 1972-06-13 Cal Val Co Flow stabilizer for pilot-operated modulating valve system
US3706320A (en) * 1971-09-21 1972-12-19 Acf Ind Inc Pressure drop variation compensating and valve positioning mechanism
US3896843A (en) * 1973-05-11 1975-07-29 Parker Hannifin Corp Pilot valve for controlling a fluid pressure operated valve
US5411053A (en) * 1994-07-01 1995-05-02 Daniel A. Holt Fluid pressure regulator
WO1997038363A1 (fr) * 1996-04-04 1997-10-16 The Curators Of The University Of Missouri Servosoupape ultrarapide a basse puissance d'actionnement

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2438938B (en) * 2006-03-24 2008-09-24 John Henry May Pilot valve
GB2438938A (en) * 2006-03-24 2007-12-12 John Henry May Pilot valve
US9644349B2 (en) 2007-01-24 2017-05-09 I2O Water Limited Controller and control system for a pressure reducing valve
GB2461451B (en) * 2007-03-22 2011-12-28 I2O Water Ltd Pilot valve for a pressure reducing valve
WO2008114036A1 (fr) * 2007-03-22 2008-09-25 I2O Water Limted Soupape pilote pour détendeur
US8978692B2 (en) 2007-03-22 2015-03-17 I20 Water Limited Pilot valve for a pressure reducing valve
CN101681176B (zh) * 2007-03-22 2013-02-13 I2O供应水有限公司 用于减压阀的先导阀
GB2461451A (en) * 2007-03-22 2010-01-06 I2O Water Ltd Pilot valve for a pressure reducing valve
AU2008228011B2 (en) * 2007-03-22 2012-02-16 Mueller International, Llc Pilot valve for a pressure reducing valve
GB2448086B (en) * 2007-03-26 2009-06-17 John Henry May Pilot valve
GB2448086A (en) * 2007-03-26 2008-10-01 John Henry May Pilot valve
US8151822B2 (en) 2007-04-20 2012-04-10 Fisher Controls International Llc Integral overpressure monitoring device
GB2450125A (en) * 2007-06-13 2008-12-17 Aquavent Uk Ltd Pressure reducing valve control
WO2008152427A3 (fr) * 2007-06-13 2009-02-05 Aquavent Uk Ltd Commande de soupape de réduction de pression
US8281803B2 (en) 2008-04-18 2012-10-09 Fisher Controls International Llc Balanced port housing with integrated flow conditioning
US8286660B2 (en) 2008-04-21 2012-10-16 Emerson Process Management Regulator Technologies, Inc. Valve body with dual sense mechanism
US8240327B2 (en) 2008-04-21 2012-08-14 Emerson Process Management Regulator Technologies, Inc. Pressure loaded service regulator with pressure balanced trim
RU2485382C2 (ru) * 2008-04-21 2013-06-20 Эмерсон Процесс Менеджмент Регьюлэйтор Текнолоджиз, Инк. Блок клапанов с механизмом двойного контроля
WO2009132007A3 (fr) * 2008-04-21 2010-12-02 Emerson Process Management Regulator Technologies, Inc. Corps de soupape à double mécanisme de détection
CN102246112A (zh) * 2008-05-20 2011-11-16 费希尔控制国际公司 用于调节流体流动的装置
RU2508569C2 (ru) * 2008-05-20 2014-02-27 Фишер Контролз Интернешнел Ллс Устройство для регулирования расхода текучей среды
WO2009142861A3 (fr) * 2008-05-20 2012-01-12 Fisher Controls International Llc Appareil permettant de réguler un écoulement de fluide
US9493931B2 (en) 2008-12-30 2016-11-15 I20 Water Limited Mains water supply processing
WO2019098867A1 (fr) * 2017-11-16 2019-05-23 Gas Teh Ltd Régulateur de pression de gaz axiale à action directe de pression de sortie et d'entrée

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AU1039899A (en) 1999-05-24

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