GB2179121A

GB2179121A - A non-return and/or anti- vacuum spring loaded valve assembly

Info

Publication number: GB2179121A
Application number: GB8520666A
Authority: GB
Inventors: Albert Fletcher Wigley
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-08-17
Filing date: 1985-08-17
Publication date: 1987-02-25
Also published as: GB2179121B; GB8520666D0

Abstract

A sub-unit valve body 10 has an external flange 11 for incorporating in preferably metal valve bodies and an internal bore 14 in which an open flanged cage 18 oscillates according to fluid pressure or vacuum conditions. A valve chamber has three different valve seating portions 15, 16, 17 which cooperate with a two part valve closure 27, 28 which is attached to the base of the cage. Valve closure part 28 is resilient and contacts seat portion 15 under no flow conditions. Under back pressure the valve member rests into the seating with rigid part 27 contacting seat portion 17 and resilient part 28 contacting seat portions 15, 16. <IMAGE>

Description

SPECIFICATION Improvements in or relating to fluid control valves This invention relates to a dual purpose non return valve and/or an anti-vacuuum valve assembly for incorporating as a sub-unit in various configurations of valve bodies with inlets and outlets for inclusion in fluid flow lines and in particular for installation for the prevention of backflow and back-syphonage in drinking and domestic water supplies from public water mains.

The valve section of the sub-unit assembly has more than one valve seating and valve closure and is operated by fluid pressure and/or vacuum pressure assisted by a compression spring. It can withstand pressures higher than those normally associated with such devices in the water industry and can be removed replaced and renewed and can be installed in any orientation.

Devices for allowing fluid to flow in one direction only are invariably designed for specific purposes and installation requirements and it is generally assumed that the pressurised supply will return to atmospheric pressure. The present invention is designed for vacuum conditions occuring in the supply line on such occasions when the public water main fractures or is exhausted by Fire appliances and the water supply to multi-storey buildings is shut down.

The new Model Water Byelaws 1986 will require prevention devices and service valves to be installed at all draw off points where substances which can be harmful to health can be drawn back into the drinking domestic water supply and public water mains.

The present invention will satisfy these requirements regarding service valves with protective devices, combined non-return and antivacuum valves and combine stop valves with non-return and anti-vacuum valves for installation in any orientation.

According to the present invention there is provided a triple stage spring loaded non-return and/or an anti-vacuum valve assembly sub-unit comprising a number of parts that when assembled can be incorporated or integrated in a valve body with an inlet and outlet either-or as (a) an individual non-return valve, (b) a combination stop valve with test plug and non-return valve, (c) a combination of a non-return valve with the anti-vacuum valve on the inlet side, (d) a valve body comprising a stop-valve, non-return valve and an anti-vacuum valve.The valve assembly sub-unit can also be incorporated in various configurations of valve bodies with inlets and outlets at different angles or as in-line devices for insertion in existing or proposed fluid flow lines and particularly for the prevention of backflow or back-syphonage in drinking and domestic water supplies and other situations where such devices are necessary. The valve assembly sub-unit comprises a rigid valve body with flanges for incorporating in various configurations of valve bodies having inlets and outlets. The rigid valve body of the valve assembly sub-unit has three types of valve seatings in its interior/exterior surfaces. Two types of valve closures are attached to a rigid cage with a flanged head for confining a compression spring.The cage has four radial guide arms equally spaced aid a convex base to which are attached by means of a threaded nut and bolt a metal domed pressure plate valve closure, a cup shaped deformable elastomeric valve closure, and a rigid washer for securing a watertight joint between the valve closures when the bolt and nut compresses the valve closue units together. The radial guide arms oscillate through a control aperture or bore of the rigid flanged body by means of water pressure, vaccum or minus pressure assisted by a compression spring stabilised on the flanged part of the rigid valve body and confined in the flanged head of the cage.

When the parts are assembled and tested the sub-unit is interchangeable and renewable. The configuration of the valve seats and valve closures together with the various types of ma terial that are used and can be used in the manufacture of the individual parts of this valve assembly sub-unit ensures that the valve closures do not adhere to the valve seats after continuous high pressure and above normal temperature.

A specific embodiment will now be described by way of example and with reference to the accompanying drawings in which: Figure 1 shows a section of a valve assembly sub-unit with the valve closures in the open position.

Figure 2 shows a section of the valve assembly sub-unit with the valve closures in a first sealing position Figure 3 is a section of a valve assembly sub-unit with the valve closures in their respective seating and sealing positions.

Figure 4 is an illustrated section of a nonreturn valve body with inlet and outlet connections incorporating a valve assembly sub-unit in a closed position.

Figure 5 is a sectional illustration of an inline combined non-return and anti-vacuum valve body with inlet and outlet connections incorporating an anti-vacuum valve assembly sub-unit and a non-return valve assembly subunit.

Figure 6 is a sectional illustration of a combined stop valve non-return and anti-vaccum valve body with inlet and outlet connections incorporating non-return and anti-vacuum valve assembly sub-units Figure 7 is a combined stop valve and headwork with test chamber and plug and incorporating a non-return valve assembly sub unit. The valve body has inlet and outlet connections.

Figure 8 is a sectional illustration of a combined stop valve body with headwork and with an anti-vacuum assembly sub-unit and 2 non-return valve assembly sub-units connected by means of a test chamber with a test plug.

The body has inlet and outlet pipe connections.

Figure 9 is a sectional illustration of a Tee shaped fitting as described for Fig. 5 but with side inlet and bottom outlet connections.

Referring to the drawing-Fig. 1, shows a section of a valve assembly sub-unit with two valve closures ejected from valve seatings within a rigid valve body. The valve closures are maintained in this position during a pressurised flow through the valve body. The valve assembly sub-unit comprises a rigid preferably plastic body 10 with flanges. 11 and 12 for incorporating in a valve body with an inlet and outlet. The body 10 has a central aperture or bore 14, an internal/external periphery valve seating 15 an internal convex valve seating 16 and a recessed valve seating 17.Within the aperture 14 an open cage 18 with four equally spaced guide arms 20 has a circumferential recessed flanged head 21 into which a compression spring 22 is shown -compressed. The flanged head 21 rests upon an upstand of the body 24 which limits the movement of the cage 18, the upstand 24 convalises the base of the spring 22 which rests upon the flange 12 of the body 10. The guide arms 20 of the cage 18 terminate in a concave base plate with a central aperture 26.

A domed metal valve closure with a central aperture 27 is in symetrical contact with the base plate 26. In symetrical contact with the domed valve closure 27 is an elastomeric deformable cuplike valve 28 which has a thin wall periphery rim increasing in thickness to a retention boss with a central aperture 29. The retention boss 29 is enclosed within a recess of a rigid, preferably plastic washer with a central bore 30. A metal bolt preferably stainless steel 32 passes through apertures 26, 27, 28, 29, 30 and when a threaded nut 34 is secured on the bolt and tightened the valve closures are compressed and a watertight joint is achieved.

Referring to Fig. 2, this shows the elastomeric deformable valve closure 28 pressed on the valve seating 15 when a no flow situation occurs through the valve assembly. The sealing of the valve seating 15 is due to the elastomeric valve 28 being fractionally larger in diameter than the valve seating 15 and is subject to a slight pressure from the compression spring 22 and is referred to as the first seating position. In this position the valve 28 is sensitive to flow and reverse flow pressures.

Referring to Fig. 3. This sectional illustration shows the valve closures 27 and 28 in their respective seating positions 16 and 17 within the body 10. This position is caused by the elastomeric valve 28 being subject to a dominant back pressure which deforms the valve and forces both valves 27 and 28 into their respective seatings. Assuming this is caused by a minor dominant pressure the thinner walls of the valve 28 would be pressed against the concave surfaces of the body 10 without the metal domed valve 26 being subject to pressures. This is referred to as the second sealing. If however a vacuum occurs in the inlet supply pipe the valves 27-28 will be forced into their seatings, full back pressure will occur and in this case the domed metal valve 27 will absorb the pressure that will be transferred through the thicker part of the elastomeric valve 28.If a foreign body is lodged between the seating 17 and the valve closure 27 the walls of the elastomeric valve 28 pressing against the valve seating 16 will sustain a watertight seal across the valve. The non-adhesive qualities of the metal domed valve 27 and the rigid valve seating 17 together with the configuration of the elastomeric valve closure 28 and valve seating 16 enables the combined closures to be ejected from their seatings and the valve body with the minimum of resistance after continuous and excessive pressure over a long period.

Referring to Fig. 4. This longitudinal sectional view of a non-return valve fitting illustrates the means of incorporating a valve assembly sub-unit between the half sections of a valve body comprising an inlet 40 an inlet chamber 41 with male thread 42 and a square faced end 43 which compresses the flange 11 of the sub-unit body 10. A female threaded section of the valve outlet chamber 44 with an internal flange 45 compresses the flange 12 of the sub-unit body 10 when the two halves of the valve body are screwed together and a watertight joint achieved. When a pressurised flow of fluid occurs through the valve the valve closures 27 and 28 are ejected from the valve body 10 as shown in Fig. 1 into the outlet chamber 46 and the fluid flows freely around the valve closures and discharges through the outlet 48 of the valve unit.

Referring to Fig. 5. This illustrates a longitudenal section of an inline combined non-return and anti-vaccum fitting with inlet and outlet for pipe connections. The combined unit comprises a valve assembly sub-unit 50 incorporated as a closed anti-vacuum valve sub-unit in a Tee section of a valve fitting. An air inlet Cap 52 with air inlet apertures 54 secures the flanges of the sub-unit body 10 by means of male and female threads to the valve body in the same manner as described in Fig. 4. A valve assembly sub-unit 56 identical in features to the sub-unit 50 is secured in an outlet chamber 58 of the Tee fitting in the same manner as described for the non-return subunit in Fig. 4. with the sub-unit flanges 11 and 12 compressed and made watertight between male and female threads.The non-return valve closures 27 and 28 are shown in the open position free of the body 10 but restricted in operation by the flanges of the open cage 19.

The open position is sustained by pressurised fluid flow through the valve cage around the valve closures and discharging though the outlet of the valve. However, should a vacuum situation occur in the supply line, generally due to water main fractures or stop valves closed in multi-storey buildings the non-return valve closes and the anti-vacuum valve opens and releases the vacuum pressure on the inlet side of the non-return valve. When normal pressures return in the supply pipe the antvacuum valve closes and the non-return valve opens and this combination of valves always act in sequence when vacuum conditions occur in the supply system providing the valves are incorporated in the manner shown. It is accepted that these conditions do not often occur and the anti-vacuum valve can be under substantial pressures for long periods of time.

It is important that valve closures do not adhere to valve seatings in this type of protection device.

Referring to Fig. 6. The illustration shows a sectional view of a combined stop valve with headwork, non-return and anti-vacuum valve incorporated in a valve body with an inlet and outlet for pipe connections. The combined fitting comprises a valve body 60 inlet with pipe connection 61, anti-vacuum valve assembly sub-unit 62, air inlet cap 63, stop valve 1010 headwork 63, non-return valve assembly subunit 65 outlet with pipe connection 66. The operating sequence of the anti-vacuum valve and non-return valve is as described for Fig.

5. With this particular stop valve unit the stop valve can be closed during a pressurised flow the anti-vacuum valve assembly sub-unit removed, inspected, and tested, the non-return valve can be checked if leakage occurs through the anti-vacuum aperture and after inspection the anti-vacuum sub-unit can be replaced. This immediate check of protection valves is of value when contaminated water occurs in drinking water supplies and valves must be tested without shutting down services and disconnecting supply pipes.

Referring to Fig. 7. This shows a sectional illustration of a Combined Stopvalve body 70, a 1010 headwork 72, test plug aperture 74 and test plug 75. A non-return valve sub assembly unit 76 is incorporated in the outlet chamber of the stop valve body in the manner described in Figs. 4, 5, 6. This unit is appropriate for use as a protective service valve to individual water using fittings and fitments.

The non-return valve can be tested by closing the stop valve, removing the plug and observing if leakage occurs at the plug aperture.

Fig. 8 is a sectional illustration of a combined unit where extra precautions have to be taken in providing protection against backflow and backsyphonage. If one return valve malfunctions the alternative valve acts as a safety factor. Each of the three valves shown can be tested in the manner described in Figs. 6 and 7. The combined unit comprises a stop valve body 80, an inlet with union pipe connections 82, anti-vacuum valve assembly sub-unit 83, air inlet cap 84, 1010 stop valve headwork 85, first non-return valve assembly sub-unit 86, test plug chamer 87, test plug aperture and test plug 88, second non-return valve assembly sub-unit 89 and discharge outlet 90 with union pipe connections. All the valves are incorporated in the valve body in the manner described in Figs. 4 to 7. Immediate tests of this valve can be undertaken during a pressurised flow in the same manner as described in Figs. 6-7.

Fig. 9 is a sectional illustration of a combined non-return and anti-vacuum valve fitting with side inlet and bottom outlet body. The valve assembly sub-units are similar in features to those incorporated and described in Fig. 5. This illustration is a further indication of the various configurations of valve bodies into which this valve assembly sub-unit can be incorporation.

Claims

1. A spring loaded multi-stage valve assembly sub-unit comprising a number of parts that when assembled can be incorporated or integrated as a non-return valve and/or an anti-vacuum valve in valve bodies-preferably of metal-of various configurations with more than one aperture including an inlet and outlet for insertion or installing into existing or proposed fluid flow lines.

2. A spring loaded multi-stage valve assembly sub-unit as claimed in Claim 1 comprising a rigid valve body with a central bore and a larger diameter valve chamber with the body having external flanges for incorporating or integrating in various configurations of valve bodies having inlets and outlets. Within the valve chamber of the rigid valve body, three types of valve seatings are located at various levels and within the central inlet bore a cage with radial guide arms oscillates in response to various pressure variation and vacuum conditions that -occur in fluid flow lines. A flange on top of the cage encloses a loaded compression spring with the base of the spring centralised on an upstand of the flange of the rigid valve body and which restricts the travel of the cage.At the base of the cage within the valve chamber and attached to the guide arms is a convex member with a central aperture through which a preferably stainless steel or metal bolt secures a domed metal pressure plate valve closure with a central aperture together with a cup shaped deformable elastomeric valve closure with a central aperture and a recessed rigid washer for securing a water tight joint between the valve closures and the base of the cage when the bolt and unit compresses the valve closures together. When the separate parts are assmebled in the manner previously described the valve sub-unit can be incorporated in various types of valve bodies by compressing the flange of the rigid valve body between the spigot and socket ends of the valves with connectors for inclusion in fluid flow lines.

3. A spring loaded multi-stage valve assembly sub-unit as claimed in Claims 1 and 2 wherein the valve seatings are individual configurations at various levels in the valve chamber and the valve closures are manufactured in dissimilar materials i.e. one being of metal, preferably of stainless steel that will sustain very high pressures and the second valve closure being deformable elastomeric material that will respond to light and medium pressures. This combination of two types of valve closures operating on the rigid preferably plastic seatings within the valve chamber and able to withstand continuous high pressure and various temperature conditions without adhering to the valve seatings.

4. A spring loaded multi-stage valve assembly sub-unit as claimed in the preceding Claim wherein when incorporated in a valve body with an inlet and outlet and installed in a fluid flow line as a non-return valve the combined metal domed pressure plate valve together with the deformable elastomeric cupshaped valve closures will be ejected from their seatings within the valve chamber by a pressurised flow in the supply pipe to an extenal forward position outside the valve chamber and maintained in this desired position by the flange of the cage restricted by the upstand on the flange of the rigid valve body with the spring in a compressed condition.

When a no-flow period occurs the deformable elastomeric valve closure being diametrically larger than the periphery rim of the valve chamber will achieve a primary seating and sealing position on the inner periphery rim of the valve chamber by the force of the compression spring to which the valve closures are attached. This rim position will be maintained until a dominant pressure either forces the two combined valve closures into their second and third valve seatings within the valve chamber and prevent backflow or into a forward flow position due to a pressurised fluid flow in the supply pipe.

5. A spring loaded multi-stage valve as sembiy sub-unit as claimed in Claims 1 and 2 wherein the sub-unit can be incorporated as an anti-vacuum valve in a valve body having air inlets and an outlet that can be installed or incorporated in a fluid flow line. The valves within the sub-unit remain closed during flow periods and air is only released into the pipe system when fluid pressure is replaced by atmospheric or vacuum pressure forcing the valve closures from their seatings to the open flow position. The valve closures will revert to their closed position when fluid pressure returns to the supply system. The anti-vacuum valve only releases air into the pipe system and will not vent air from the pipe system.

6. A spring-loaded multi-stage valve assembly sub-unit as claimed in any of the preceding wherein the sub-unit is incorporated in the outlet aperture of a valve body having an inlet, a valve seating an assembled stop valve 1010 headwork threaded into an aperture above the valve seating and with or without a threaded test plug aperture and plug. The complete unit is classified as a Stop-valve with 1010 headwork and non-return valve and according to the configuration of the body.

7. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding Claims wherein a sub-unit is incorporated in a tee shaped valve body as a nonreturn valve and defined as the outlet and a similar sub-unit is incorporated in a second aperture and defined as an anti-vacuum valve, the third aperture will then be defined as the inlet and when assembled and installed or included in a fluid flow line the two multi-stage valve units will function in a sequence manner i.e. one valve will open and the other valve remain closed according to the fluid pressure or the vacuum conditions that occur in fluid flow lines. This assembled unit is classified as a combined non-return and anti-vacuum valve.

8. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding Claims wherein a valve body has a valve seating, an assembled stop valve 1010 headwork threaded into an aperture above the valve seating, a sub-unit valve assembly defined as an anti-vacuum valve incorporated in an aperture on the inlet side of the stop valve and an inlet for a pipe connection. A second sub-unit valve assembly is incorporated as a non-return valve in the outlet aperture of the valve body and when assembled and installed as a unit in a fluid flow line the two multistage valve units will function in a sequence manner while the stop valve is in the open position according to fluid pressure or vacuum conditions.

This assembled unit is classified as a stop valve non-return and anti-valve.

9. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding Claims wherein the sub-unit can be incorporated as a non-return valve and a similar sub-unit incorporated as an anti-vacuum valve in a stop valve body as described in the previous claim has means of testing either valve during flow conditions by closing the stop valve, removing and testing the anti-vacuum valve, verifying the efficacy of the non-return valve by observing leakage from the anti-vacuum valve aperture, replacing the anti-vacuum valve and opening the stop-valve.

10. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding Claims wherein a sub-unit can be incorporated as an anti-vacuum valve in a stop valve body and two similar units can be incorporated as a double non-return valve in-line assembly in the outlet aperture of the valve body. The two non-return valve sub-units are separated by a threaded aperture containing a threaded test plug. The two non-return valves act in a sequence manner with the anti-vacuum as previously described.

11. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding claims wherein the rigid parts of the sub-unit can be made from metal, plastic or non-ferrous metals.

12. A spring loaded multi-stage valve assembly sub-unit as claimed in any of the preceding Claims wherein the sub-unit can be extracted from the preferably metal valve casing tested, replaced or renewed by a similar subunit.

13. A spring loaded multi-stage valve assembly sub-unit as described herein with reference to Figs. 1-9 of the accompanying drawings.