GB2156496A

GB2156496A - Fluid pressure governor

Info

Publication number: GB2156496A
Application number: GB08513698A
Authority: GB
Inventors: Clarence Carver Smith; Paul Anthony Smith; Gerald Alfred John Springer
Original assignee: DEREVE
Current assignee: DEREVE
Priority date: 1981-04-15
Filing date: 1985-05-30
Publication date: 1985-10-09
Also published as: GB8513698D0; GB2156496B

Abstract

A fluid pressure governor comprises a moulded body (10) which defines a flow passageway (11, 12, 13, 14, 15) and a diaphragm chamber (13) which is opened at one side and closed by a diaphragm (30) trapped between the body (10) and a top member (20), and acted on by an adjustable compression spring (43) in opposition to fluid pressure within the diaphragm chamber (13). The body (10) incorporates a valve insert (50) including a movable valve member (60) having a flexible regulating portion (64) which co- operates with a seating (53), and a further flexible frusto-conical regulating portion (161) co- operating with a further seating (154) in a counter-pressure chamber (155), which is connected to the outlet (15) by an opening (16) in the body so that hydrostatic forces exerted on the valve member (60) are substantially balanced. <IMAGE>

Description

SPECIFICATION Fluid pressure governor This invention relates to a fluid pressure governor, and in accordance with the invention a governor for regulating the pressure of a supply of water or other liquid or a gaseous fluid comprises a chamber closed at one side by a diaphragm which is responsive to pressure of fluid within the chamber and is spring loaded in opposition to such pressure, and a valve member movable with said diaphragm relative to a co-operative seating to define a flowregulating constriction in a flow passage between an inlet and an outlet, the chamber being in, or in fluid communication with, said flow passage, and the valve member being substantially balanced with regard to fluid pressure on opposite sides thereof wherein the valve member affords twin regulating portions, one of which co-operates with a seating in the valve chamber and the other of which co-operates with a further seating in a counter-pressure chamber which is in, or in fluid communication with, said outlet, at least one of the regulating portions of the valve member being resilient.

The valve member may be made of a suitable plastics materials. Both regulating portions may afford a frusto-concial surface which co-acts with the respective seating, and one of such surfaces may be afforded by a solid part of the valve member formed with a notch around its periphery immediately adjacent to said surface so as to define a flexible lip. The other of said surfaces may be afforded by a hollow flexible skirt portion of the valve member.

The valve member may include a stem which extends through said seating and engages the diaphragm, a spring being provided to act on the valve member to maintain contact between the stem and the diaphragm.

The valve member may be disposed within a valve chamber which affords said seatings at opposite ends thereof, one end opening through one of said seatings into said diaphragm chamber, and the other end opening through the other seating into said counterpressure chamber.

The valve member and seating are preferably formed as an insert assembly which also defines said valve chamber. The counter-pressure chamber may also be defined by such insert assembly.

The governor conveniently comprises a casing including a body member in which said flow passage and diaphragm chamber are formed, and a top member housing a spring which bears on the diaphragm, the diaphragm being trapped between the two casing members. The diaphragm may incorporate a moulded peripheral bead whereby it also serves to establish a fluid-tight seal between the casing members.

Preferably, the casing members are formed of moulded plastics material.

These and other features of the governor in accordance with the invention will now be described by way of example, with reference to the accompanying drawing which shows a diametral section through one embodiment of fluid pressure governor in accordance with the invention.

As shown, a water-pressure in accordance with the invention includes a two-part casing comprising a body member 10 and a top member 20, each formed as a moulding of a suitable thermoplastic material, the two members being threadedly connected together.

The body member 10 is formed with an inlet bore 11 which opens into a bore 1 2 extending axially of the circular shape body member. The bore 1 2 in turn, opens into an annular diaphragm chamber 1 3 which is open at its upper side. An outlet passage 14 extends from the diaphragm chamber 1 3 at one side thereof and leads into an outlet bore 1 5 in diametrally opposed relation to the inlet bore 11.

The diaphragm chamber 1 3 is closed by means of a diaphragm indicated generally at 30. This consists of a rigid top plate 31 and a rigid lower plate 32 secured together by means of a screw 33 with a flexible diaphragm member 34 between them. The diaphragm member 34 is moulded from a suitable synthetic rubber and incorporates an annular convolution 35 and at its periphery a bead 36 of semi-circular shape in section. As can be seen, the bead 36 is received within a groove 1 6 formed in the body member 10 around the open side of the diaphragm chamber 1 3 formed therein, whilst the opposite face of the diaphragm member 34 is engaged peripherally by an annular washer 29 located in a rebate 28 formed in the top member 20 of the casing.

The top member 20 includes a hollow boss 21 which receives therein a metal insert 40 and a metal collar 41 which is threadedly engaged therewith. The collar includes a pair of diametrally opposed lugs 42 which are slidably engaged in grooves 22 which extend axially within the boss 21. A spring 43 extends between the collar 41 and the top plate 31 of the diaphragm 30 so as to act in opposition to pressure exerted on the diaphragm by fluid in the chamber 1 3.

The insert 40 is formed at its upper end with a recess 44 of non-round (e.g. hexagonal) section, and a hole 23 is formed in the end of the boss 21 whereby an appropriate tool may be inserted into the recess 44 to enable the insert 40 to be rotated. As will be apparent, rotation of the insert 40 will cause the collar 41, which is held against rotation by virtue of the lugs 42, to move axially and thereby adjust the compression of the spring 43. In this way, the setting of the regulator may be varied.

As can be seen, the top plate 31 of the diaphragm 30 is received within a central recess 27 formed at the mouth of the hollow boss 21, and the top plate 31 itself includes a stepped spigot 37, the wider part of which serves to locate one end of the spring 43, and the narrower part of which serves to locate the lower end of the insert 40.

The axial position of the diaphragm 30 will vary according to the compression of spring 43 and the water pressure existing in the diaphragm chamber 1 3.

To effect regulation of pressure, a valve assembly 1 50 is provided with the axial bore 1 2 of the body 10. The assembly 1 50 is preferably formed as a pre-assembled unit including a metal insert 151 which defines a valve chamber 1 52 in register with the inlet 11 and affords an annular seating 1 53 facing into such chamber.

At its lower end the insert affords a further seating 154, and a recess 156 is formed in its external surface and arranged to register with an opening 1 7 which extends between the outlet passage 14 and the bore 1 2 so as to place the outlet passage 14 in communication with a counter-pressure chamber 1 55 beneath the insert 1 51. An oblique groove 157 in the exterior surface of the insert houses a sealing ring 1 58 whereby the inlet and outlet are isolated.

The insert 1 51 contains a slidable valve member 1 60 which is made of a plastics material and affords a lower regulating portion 161 and an upper regulating portion 164 which co-operates respectively with the seatings 154 and 153.

The upper regulating portion 1 64 has an upper surface of frusto-conical form and a notch 1 66 is formed around this portion immediately adjacent thereto to define a flexible lip 167.

The regulating portion 161 is in the form of a hollow, frusto-conical skirt portion which is preferably sufficiently thin to be flexible. Thus, at least one of the regulating portions is effectively resilient in operation, and preferably both, so that, if due to dimensional variations in the manufacture, one portion engages its seating before the other, the other can still be drawn onto its seating because of the resilience afforded by the first portion to engage its seating under the influence of spring 1 59 which engages the lower end of the valve member 60 and bears against the lower end wall 19 of the bore 12.

The valve member 1 60 also includes a stem 1 65 having a rounded upper end 1 66a which enages in a corresponding hemispherical recess 38 formed in the screw 33 of the diaphragm 30. Spring 1 59 ensures that the valve member 60 is maintained in contact with the diaphragm 30 to move therewith.

There are two parallel flow paths from the inlet 11 to the outlet 15, one by way of the diaphragm chamber 1 3 and the other by way of the counter-pressure chamber 1 55 and opening 17.

The spacing between the regulating portions and co-operative seatings will increase at the diaphragm 30 moves downwardly in response to decrease in pressure in the chamber 13, so as to admit fluid from the inlet bore 11 at a greater rate until equilibrium is re-established.

Whilst the valve member 1 60 is conveniently formed separately from the screw 33, the latter could be formed integrally with the valve member, in which case the spring 1 59 might be omitted.

The nett force acting on the valve member arising from the pressure at the outlet side of the governor is negligible since the valve member affords faces of substantially equal area at opposite ends. In this way, no significant nett force acts on the valve member as a result of differential pressure between the inlet and outlet bores, and the valve member 1 60 moves freely in the insert 151 in response to any movement of the diaphragm 30.

Whilst the diaphragm chamber 1 3 actually forms part of the flow path between the inlet and outlet bores in the embodiment illustrated, it will be appreciated that this need not be the case, so long as the diaphragm chamber 1 3 is in fluid communication with such flow path at a point between the valve seating 1 53 and the outlet bore 1 5.

Claims

1. A fluid pressure governor comprising a chamber closed at one side by a diaphragm which is responsive to pressure of fluid within the chamber and is spring loaded in opposition to such pressure, and a valve member movable with said diaphragm relative to a cooperative seating to define a flow-regulating constriction in a flow passage between an inlet and an outlet, the chamber being in, or in fluid communication with, said flow passage, and the valve member being substantially balanced with regard to fluid pressure on opposite sides thereof wherein the valve member affords twin regulating portions, one of which co-operates with a seating in the valve chamber and the other of which co-operates with a further seating in a counter-pressure chamber which is in or in fluid communication with, said outlet, at least one of the regulating portions of the valve member being resilient.

2. A governor according to Claim 1 wherein the valve member is made of a plastics material.

3. A governor according to Claim 1 or Claim 2 wherein both regulating portions afford a frusto-conical surface which co-acts with the respective seating.

4. A governor according to Claim 3 wherein one of said frusto-conical surfaces is afforded by a solid part of the valve member formed with a notch around its periphery immediately adjacent to said surface so as to define a flexible lip.

5. A governor according to Claim 4 wherein the other of said frusto-conical surfaces is afforded by a hollow flexible skirt portion of the valve member.

6. A governor according to any one of the preceding claims wherein the valve member includes a stem which extends through said seating and engages the diaphragm, a spring being provided to act on the valve member to maintain contact between said stem and the diaphragm.

7. A governor according to any one of the preceding claims wherein the valve member is disposed within a valve chamber which affords said seatings at opposite ends thereof, one end opening through one of said seatings into said diaphragm chamber, and the other end opening through the other seating into said counter-pressure chamber.

8. A governor according to Claim 7 wherein the valve member and seating are formed as an insert assembly which also defines said valve chamber.

9. A governor according to Claim 8 wherein the counter-pressure chamber is also defined by said insert assembly.

10. A governor according to any one of the preceding claims comprising a casing including a body member in which said flow passage and diaphragm chamber are formed, and a top member housing a spring which bears on the diaphragm, the diaphragm being trapped between the two casing members.

11. A governor according to Claim 10 wherein the diaphragm incorporates a moulded peripheral bead whereby it also serves to establish a fluid-tight seal between the casing members.

1 2. A fluid pressure governor substantially as hereinbefore described with reference to and as shown in the accompanying drawing.

1 3. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawing.