AU2003213322B2 - Stop/check valve for plumbing use - Google Patents

Description

P001 Section 29 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: STOPICHECK VALVE FOR PLUMBING USE The following statement is a full description of this invention, including the best method of performing it known to us: STOP/CHECK VALVE FOR PLUMBING USE FIELD OF THE INVENTION The invention is a stop/check valve for use in domestic or commercial plumbing installations, and provides a means of isolating a water supply from an attached appliance, cistern or the like and of preventing or limiting reverse flow into the water supply.

BACKGROUND

The present invention provides a means to isolate a water supply system from an appliance connected thereto such as a washing machine or a dishwasher or from a device such a cistern and is directed particularly to domestic and light commercial plumbing installations.

Appliances, cisterns and the like are normally installed with a useroperable stop valve upstream thereof, so that they can be isolated for repair or replacement. It is important to avoid or at least the possibility of reverse flow from these items into the mains water supply, as contamination of the supply may occur and affect the health of users who for example drink water from it. So-called "grey" water from dishwashers and washing machines may contain substantial amounts of fatty matter, strong detergents and the like, and the potential for contamination from cisterns is also clear, notwithstanding that measures are taken in such appliances and devices to avoid the potential for backflow of contaminated water. Backflow can occur, for example, in the event of a temporary loss of pressure and flow capacity in the water supply.

Dishwashers and washing machines often have rapid-acting solenoid valves which may cause water hammer, or at least temporarily severe pressure pulses. These can result in valve damage, a tendency to leakage at joints upstream and, depending on the characteristics of pipes and hoses involved, a degree of backflow into the water supply.

It is an object of the present invention to provide a combination stop/check valve that alleviates these problems in installations of the above types, and that is particularly compact and easy to install as a single unit. It is a further object to avoid the need for separate check and stop valves to be installed, with their higher potential for leakage. The provision of a single unit is more quickly installed than separate units, thus reducing overall costs. The device also enables easy replacement of check valve components, if necessary, without removal of the valve body.

SUMMARY OF THE INVENTION A stop/check valve for use in plumbing installations including: a body having an inlet and outlet passages formed integrally within said body, said passages terminating respectively at inlet and outlet ports; a valve assembly received in said body and operable by a user to permit or prevent fluid communication between said inlet and outlet passages; a non-return valve secured in said outlet passage of said body between said valve assembly and said outlet port and arranged to permit flow only in a direction from said inlet port to said outlet port; said valve assembly including: a spindle housing threadably received in said body; a spindle rotatably and sealingly received in said spindle housing; and a first sealing component abutting a second sealing component, said first sealing component being received and supported in said body and said second sealing component being rotatable within said body by said spindle between fully-closed and fully-open positions relative to said first sealing component, wherein in said fully-closed position of said second sealing component, fluid communication between said inlet and outlet passages is prevented and in said fully-open position of said second sealing component said inlet and outlet passages are in fluid communication with each other, wherein said first sealing component and said second sealing component are ceramic discs having respective flat faces; ceramic disc sealing components wear better than (for example) conventional fibre washers sealing against brass sets. They also lend themselves to a provision of a valve with internal cavities that are comparatively compact, which is desirable in a valve whose purpose include the minimisation of backflow and possible contamination of a water supply. The combination of ceramic stop valve sealing components and a non-return valve assembly in the outlet passage of the valve body has proven surprisingly space-efficient, effective and inexpensive to produce.

It is preferred that said non-return valve is held captive in said outlet passage by retaining means and that said retaining means is able to be withdrawn from said outlet passage through said outlet port so that said nonreturn valve is thereafter able to be withdrawn from said outlet passage through said outlet port. This provides for both easy manufacture and easy replacement of the non-return valve as a unit, without any necessity for disconnection of the stop/check valve from water supply. In installations of appliances such as dishwashers and washing machines, whose solenoid-operated valves may close suddenly, severe pressure pulses may be generated in attached hoses or pipes and transmitted to the stop/check valve. This may eventually lead to damage to the non-return valve components, making easy replacement an important issue.

The retaining means may be a snap ring or circlip, for example.

The non-return valve is preferably a single unit, including a fixed part having a sealing surface and a movable part adapted to seal against said sealing surface thereby to prevent flow of a liquid from said outlet port to said outlet port.

Non-return valve assemblies are available wherein said fixed part is a plastics injection moulding and said movable part is captive in said fixed part. The stop/check valve of the invention is particularly suitable for the use of such assemblies.

The body is preferably so formed that said inlet passage is substantially circular in cross-section having a central axis that is coaxial with said spindle. It is also preferred that said outlet passage is substantially circular in cross-section having a central axis that is at least approximately perpendicular to the central axis of said inlet passage. This arrangement lends itself well to installation of washing machines, dishwashers and the like, and to cistern installations.

The present invention will be better understood and appreciated from the following discussion of the features of a preferred embodiment. It is relevant that other embodiments of the invention may be appropriate in addition to the forms herein described. Reference is made to the accompanying drawings in which: Figure 1 is a front isometric view of a first valve embodying the invention; Figure 2 is a rear isometric view of a second valve embodying the invention; Figure 3 is an exploded view of the valve shown in Figure 1; Figure 4 is an exploded view of the spindle assembly of the valve shown in Figure 1; Figure 5 is a cross-sectional view of the valve of Figure 1 in an "open" condition; Figure 6 is a cross-sectional view of the valve of Figure 1 in a "closed" condition.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Figure 1 is a front isometric view of a stoplcheck valve 1 according to the invention. Valve 1 has an integrally cast metal body 2 with an inlet port 3 having a Inch female BSP threaded section 4 coaxial with external spanner flats 5 and a Inch male BSP threaded section 6 surrounding an outlet port 21, and a handle 7.

Figure 2 is a rear isometric view of a second stop/check valve 8 according to the invention. This embodiment is suitable for cistern applications, and has a /2 Inch female BSP threaded section 9, spanner flats 10 coaxial therewith, and a Y inch BSP male threaded section 11 on its body 12. Also provided is a handle 13.

Valve 8 is the same in its general arrangement and construction as valve 1.

Therefore the following description will be based on valve 1 only.

Referring to Figure 3, there is shown an exploded view of valve 1. Body 2 has a generally cylindrical main section 14 and an outlet branch 15 extending perpendicularly therefrom, threaded section 6 on this branch 15 surrounding outlet port 21. A spindle assembly 16 is received threadably and sealingly in body 2. Handle 7 is secured to spindle 18 of spindle assembly 16 in known manner by a screw 19 and has a red or blue plastics cap Received within an outlet passage 22 in branch 15 is a non-return valve assembly 23. Non-return valve assembly 23 is assembled into (and can be withdrawn from) body 2 through the outlet port 21, and retained in passage 22 by a snap ring 24.

Figure 4 is an exploded view of spindle assembly 16. The rotatable spindle 18 rotates a movable ceramic disk sealing element 25 which abuts and is sealingly urged against a fixed ceramic disk sealing element 26. The spindle 18, disks 25 and 26 and a resilient grommet 27 and ring 28 are received in a housing 29. When spindle assembly 16 is secured in body 2, deformation of grommet 27 causes urging together of disks 25 and 26. Turning spindle 18 through a quarter turn (90 degrees) causes the disks to move between "open" (flow-permitting) and "closed" (flow-preventing) relative positions in known manner. Note that none of disk 25, disk 26, and spindle 18 moves axially in use of the valve 1. Sealing of the spindle 18 in housing 29 is by O-rings Figures 5 and 6 are cross sectional views of the assembled valve 1, sectioning being in a plane containing central axes of the spindle 18 and outlet passage 22, these views respectively showing both the ceramic disks 25 and 26 and the non-return valve assembly 23 in the open and closed positions. In the open position, water can enter body 2 through inlet port 3, pass through inlet passage 30 through openings in disks 25 and 26, and out of housing 29 through ports 31 into outlet passage 22.

Non-return valve assembly 23 has a moulded plastics cage 40, and a movable element 41 which when water is flowing is clear of a seat 42 of cage When water attempts to flow in the opposite direction through non-return valve 23 in through outlet port 21) movable element 41 seats on seat 42, to stop such flow.

Housing 29 is sealed to body 2 by an O-ring 51.

It will be noted that the arrangement shown is very compact with comparatively small internal cavities in body 2, so that collection therein of contaminated backflow water is limited.

It will be seen from the description above that the present invention provides a means to isolate a domestic water main supply system from any attached appliance such as a washing machine or a dishwasher or from a cistern or the like.

It will be understood that modifications and alterations may be made by those skilled in the art without departing from the spirit and scope of my invention and I do not wish to be limited to the positive terms employed herein.

Claims (8)

1. 2. A stop/check valve according to claim 1 wherein said non-return valve is held captive in said outlet passage by retaining means and wherein said retaining means is able to be withdrawn from said outlet passage through said outlet port so that said non-return valve is thereafter able to be withdrawn from said outlet passage through said outlet port.
2. 3. A stop/check valve according to claim 2 wherein said non-return valve includes a fixed part having a sealing surface and a movable part adapted to seal against said sealing surface thereby to prevent flow of a liquid from said outlet port to said inlet port.
3. 4. A stop/check valve according to claim 3 wherein said fixed part is a plastics injection moulding and said movable part is captive in said fixed part.
4. 5. A stop/check valve according to claim 1 wherein said inlet passage is substantially circular in cross-section having a central axis that is coaxial with said spindle.
5. 6. A stop/check valve according to claim 4 wherein said outlet passage is substantially circular in cross-section having a central axis that is at least approximately perpendicular to the central axis of said inlet passage.
6. 7. A stop/check valve according to any one of claims 1 to 6 wherein: said body has a inch male BSP thread formed thereon for connection of an external fitting to said outlet port; a 1/2 inch female BSP thread is formed in said body for connection of a pipe or a further external fitting to said inlet port; and said body has spanner flats formed externally on said body and positioned for use in connecting said inlet port of said valve to a fixed threaded pipe.
7. 8. A stop/check valve according to any one of claims 1 to 7 wherein: said body has a 2 inch male BSP thread formed thereon for connection of an external fitting to said outlet port; a 1/2 inch female BSP thread is formed in said body for connection of a pipe or a further external fitting to said inlet port; and said body has spanner flats formed externally on said body and positioned for use in connecting said inlet port of said valve to a fixed threaded pipe.
8. 9. A stop/check valve substantially as described herein with reference to Figures 1 and 3 to 6 inclusive. 8 A stop/check valve substantially as described herein with reference to Figure 2. PETER MAROTTA Cc, Cc, Cc, WATERMARK PATENT TRADE MARK ATTORNEYS P23023AU00