GB2190981A

GB2190981A - Valve

Info

Publication number: GB2190981A
Application number: GB8613166A
Authority: GB
Inventors: Gordon Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-05-30
Filing date: 1986-05-30
Publication date: 1987-12-02
Also published as: GB8613166D0

Abstract

A preferably cup-shaped valve member (12) movable between first flexible peripheral portion (13) and second seats has a resiliently arranged to be deflected from a third seat, e.g. provided by the inner wall of a chamber (6), by sufficient positive pressure between an inlet port (4) and outlet port (5). When the pressure drops below a minimum or becomes negative, the portion 13 moves into contact with the internal wall of the chamber (6) to prevent back-flow from outlet port (5) to inlet port (4). At the same time the member (12) is moved (preferably assisted by spring 14) to block the inlet port (4) and to open bleed port (10) connected to atmosphere to exhaust flow from the outlet port (5) or allow entry of air. <IMAGE>

Description

SPECIFICATION Valve This invention relates to a valve and in particular to a valve for insertion between a mains water supply and a take off connection for water such as a flexible hose.

Many domestic and industrial appliances requiring a supply of water from the mains must be fitted with means for preventing the siphonage of polluted water from the service connections for the appliances back into the mains in order to avoid the pollution of the water supply. There is an increasing awareness that such anti-siphonage measures should be taken generally where a device or appliance is being connected to the mains water supply.

It is an object of this invention to provide an improved valve for preventing back siphonage or back flow of polluted water into the mains supply.

According to this invention there is provided a valve comprising a body having inlet and outlet ports communicating with an intermediate chamber through which fluid is to flow when passing from the inlet port to the outlet port, a bleed port being arranged to interconnect said chamber with the atmosphere outside the valve, a valve member of flexibly deformable material arranged within said chamber so as to be movable between a first position in which the valve member is seated in a fluid-tight manner against a first seat associated with a first of said ports and a second position in which the valve member is seated in a fluid type manner against a second seat associated with a second of said ports, the valve member having a peripheral portion which is flexibly deformable in response to fluid pressure between a position in which said peripheral portion is seated against a third seat associated with the third of said ports and a position in which the peripheral portion allows passage of fluid between said third port and said chamber, the arrangement being such that when sufficient fluid pressure is provided through said inlet port said valve member allows flow of liquid from the inlet port to the outlet port and when there is insufficient or negative pressure between the inlet and outlet port, the valve member blocks the passage of fluid between said outlet and inlet ports and allows fluid communication between said outlet port and said bleed port.

Preferably, the valve member comprises a cup seal of a resiliently deformable material such as a rubber or plastics material and is resiliently biased to said negative pressure position when not in use.

In a preferred form, said first second and third ports comprise said inlet, outlet and bleed ports respectively. The entire periphery Df the valve member may comprise said flexibly deformable portion serving to control flow betwen said inlet and outlet ports.

The valve may be provided with means for connetion to a tap connected to the mains, said connection means being provided with means for permanently inhibiting removal of the valve from the tap.

An embodiment of this invention will now be described, by way of example, with reference to the accompanying drawing in which Figure 1 is a sectional view of a valve embodying this invention; Figure 2 is an end elevation of the valve shown in Fig. 1.

Referring to the drawing, a combined nonreturn, air intake and dump valve comprises a valve body 1 having an internally screw threaded connecting portion 2 for connection to a mains tap and a connecting portion 3 for connection to a flexible hose for delivering water from the mains.

The connecting portion 2 provides an inlet port 4 and connecting portion 3 provides an outlet port 5 both of which ports are arranged to communicate with a central chamber 6.

The central chamber 6 is connected by means of bores 7 to a chamber 8 connected to the outlet port 5.

The connecting portion 3 is also provided with a longitudinally extending hollow spigot portion 9 arranged to provide a bleed port 10 connected to a plurality of bores 11 leading to the atmosphere outside the valve.

Arranged within the chamber 6 is a cup shaped valve member 12 made of a resiliently flexibly deformable plastics material and having a peripheral portion 13 of tapered cross-section as shown in the drawing which normally takes up the position shown in broken line in the drawing to seat against the internal wall of the chamber 6. A compression spring 14 serves to bias resiliently the valve member 12 towards a seat 15 provided around the inlet port 4 when there is insufficient fluid pressure through the inlet port, as when the mains supply has been turned off.

The connecting portion 1 is provided with an interenally screw-threaded bore 16 into which a set screw 1 7 having a sharpened end portion 18 can be inserted to secure the valve on to a tap by engaging and deforming the external screw thread of the tap. In this way the valve is permanently inhibited from being removed from the tap so that the valve cannot be by-passed.

In operation, when mains water pressure is applied through the inlet port, the valve member 12 is pushed against the resilient bias of the spring 14 onto the seat provided by the spigot portion 9 to seal the bleed port and prevent communication between the chamber 6 and the atmosphere. At the same time, the pressure of the mains supply causes deformation of the peripheral portion 13 of the valve member to the position shown in solid line in the drawing thereby enabling passage of the water from the inlet port through the bores 11 to the outlet port 5.

When there is insufficient mains pressure, or when there is excessive back pressure as when the hose is lifted too high above the mains supply tap, or when there is back siphonage in the mains, the peripheral portion of the valve member seats against the internal wall of the chamber assisted by such negative pressure difference as exists between the inlet and outlet ports while the spring 14 together with any back pressure moves the valve member to seat against the seat 15 and thereby block the inlet port 4. At the same time, a connection is established between the outlet port 5 and the bleed port 10 so that either air can enter through the bleed port to allow the water in the hose to drain from the latter or in the case where the water in the hose is creating back pressure the water from the hose can drain off through the bleed port to the exterior of the valve.

Although the valve as shown in Fig. 2 has a hexagonal outline, the shape could take many other forms and might typically be circular where the valve body is generally a right circular cylinder. Clearly alternative configurations to the one described above are possible and in various sets of circumstances the three seating portions of the valve member may be associated with different ones of the inlet outlet and bleed ports to those described above.

It will be appreciated that the valve described above provides a simplified and relatively inexpensive means of preventing back siphonage between various appliances and main water supply.

The valve described above can, as described, be connected to the threaded outlet or the hose union of a tap or other form of standpipe and can be provided with any desired combination of connecting portions both male and female to enhance the versatility of the valve.

Claims

1. A valve comprising a body having inlet and outlet ports communicating with an intermediate chamber through which fluid is to flow when passing from the inlet port to the outlet port, a bleed port being arranged to interconnect said chamber with the atmosphere outside the valve, a valve member of flexible deformable material arranged within said chamber so as to be movable between a first position in which the valve member is seated in a fluid-tight manner against a first seat associated with a first of said ports and a second position in which the valve member is seated in a fluid type manner against a second seat associated with a second of said ports, the valve member having a peripheral portion which is flexibly deformable in response to fluid pressure between a position in which said peripheral portion is seated against a third seat associated with the third of said ports and a position in which the peripheral portion allows passage of fluid between said third port and said chamber, the arrangement being such that when sufficient fluid pressure is provided through said inlet port said valve member allows flow of liquid from the inlet port to the outlet port and when there is insufficient or negative pressure between the inlet and outlet port, the valve member blocks the passage of fluid between said outlet and inlet ports and allows fluid communication between said outlet port and said bleed port.

2. A valve according to claim 1, wherein the valve member comprises a cup seal of a resiliently deformable material such as a rubber or plastics material and is resiliently biased to said negative pressure position when not in use.

3. A valve according to claim 1 or claim 2, wherein said first second and third ports comprise said inlet, outlet and bleed ports respectively.

4. A valve according to any one of the preceding claims wherein the entire periphery of the valve member comprises said flexibly deformable portions serving to control flow between said inlet and outlet ports.

5. A valve according to any one of the preceding claims, wherein there is provided means for connection to a tap connected to the mains, said connection means being provided with means for permanently inhibiting removal of the valve from the tap.

6. A valve substantially as described herein with reference to the accompanying drawing.