GB2300695A

GB2300695A - A water supply assembly

Info

Publication number: GB2300695A
Application number: GB9609445A
Authority: GB
Inventors: Christopher Shelsen Lowe
Original assignee: Worcester Heat Systems Ltd
Current assignee: Bosch Thermotechnology Ltd
Priority date: 1995-05-06
Filing date: 1996-05-07
Publication date: 1996-11-13
Anticipated expiration: 2016-05-07
Also published as: GB2300695B; GB9609445D0

Abstract

A water supply assembly comprises a supply conduit 21, for connection to a mains water supply 22, the supply conduit including a shut-off valve 23 leading to a supply port 25. The assembly also includes an inlet conduit 33 for connection to a water-using appliance, the inlet conduit including two non-return valves 34, 35 and having an inlet port which is spaced from the supply port 25. The supply and inlet ports each communicate with the interior of a fixed hollow cylindrical housing 29 which is open at both ends. A removable connector 38 may be introduced into the housing 29, the connector having a peripheral groove 40 which then provides fluid communication between the inlet and supply ports so as to permit a temporary flow of water from the mains to the appliance, so long as the connector is in position. However, when the connector 38 is removed from the housing 29 the separation between the supply and inlet ports means that there is no possibility of back flow from the appliance to the mains supply. The assembly, which may be used in the filling or topping-up of a domestic central heating and hot water system, eliminates any risk of back contamination of the mains supply.

Description

Improvements in or relating to Water Supply Assemblies The invention relates to water supply assemblies and particularly to an assembly for providing a temporary connection between a water-using appliance or system and the mains water supply.

In some kinds of water-using appliances or systems the pipework and devices within the system are in a closed circuit and do not require a constant supply of water from the mains to be available. For example, one common form of such a system is a domestic central heating and hot water supply system where the boiler and radiators form part of a closed primary heating circuit, water heated by the boiler being recirculated through the radiators. The primary circuit may also include a heat exchanger, and hot water for domestic use may be provided by passing cold mains water in a secondary circuit through the heat exchanger in the primary circuit. In this case there is no connection between the secondary and primary circuits other than the transfer of heat in the heat exchanger.

Since the water in such a primary circuit often contains additives and can be heavily contaminated, strict byelaws prohibit permanent connection of the primary heating circuit to the mains supply in order to avoid contamination of the mains supply.

However, when such a system is first commissioned it is necessary to fill the primary circuit with water from the mains supply, and temporary connection at subsequent intervals may also-be required to top up the circuit to compensate for losses. Such temporary connections are only permitted if effective precautions are taken to prevent contamination of the mains supply. For example, it is currently required in the United Kingdom that if a primary circuit is supplied or topped up directly from a mains supply pipe, the inlet conduit ofthe system to which the supply pipe is connected must include two non-retum valves to prevent the back-flow of water from the primary circuit to the mains supply pipe.Furthermore, the connection between the inlet conduit of the system and the mains supply pipe must be by means of a temporary connecting device which must be removed immediately after the system has been charged or topped up, so as to disconnect the system completely from the mains supply.

Conventionally, such temporary connection has been in the form of a length of flexible hose having at opposite ends thereof couplings for connecting the hose to the mains supply pipe and the inlet conduit of the primary circuit of the system, which is sometimes located in the system boiler. However, such an arrangement suffers from certain disadvantages.

For example, the installation of the boiler requires that the boiler be spaced from the mains supply pipe at such a distance and in such a location that access may be obtained to fit the temporary flexible hose when required. In practice, due to problems of access, and the trouble and inconvenience of connecting the pipe couplings at the ends of the flexible hose, it may be tempting for the installer or user to leave the flexible hose permanently in position, relying on the non-return valves and the stopcock in the main supply pipe to prevent back-contamination. This obviously leaves a risk that such contamination could conceivably occur, whereas complete removal of the flexible hose makes such contamination impossible.If the flexible hose is removed after use, as required, it may be inconvenient to store and may be found to be damaged or missing when next required for topping up the system. It may also be desirable for the anticontamination assembly to be located within the boiler casing itself so that the boiler may then be simply and conveniently directly connected to the mains supply. However, there is usually insufficient space within the boiler casing to incorporate a removable flexible hose of the kind normally used outside the boiler and, in any case, the inconveniences of fitting, removing and storing such a hose would remain.

The present invention therefore sets out to provide a novel form of water supply assembly for connection between the mains supply and a water-using appliance or system which provides the equivalent anti-contamination effect of the removable flexible hose, but in more convenient form and in a form which, in preferred embodiments, may be of comparatively small dimensions so that it can be fitted within a conventional boiler casing or other restricted space.

According to the invention there is provided a water supply assembly comprising a supply conduit, for connection to a mains water supply and having a supply port, a shut-off valve in the supply conduit, an inlet conduit for connection to a water-using appliance or system, and having an inlet port spaced from said supply port, at least one valve in said inlet conduit, a support structure which is substantially fixed in relation to said supply and inlet ports, and a removable connector for detachable engagement with said support structure, the connector, when in engagement with said support structure, providing a temporary flow passage between the supply port and the inlet port.

The valve in the inlet conduit is preferably a non-return valve arranged to prevent the flow of water outwardly along said conduit towards said inlet. Preferably also there are provided two such non-return valves in series in the inlet conduit. A test port may be provided between the non-return valves to enable the effective operation of the valve further from the inlet port to be checked. As previously mentioned, the provision of two non-return valves may in fact be necessary to comply with relevant byelaws.

The support structure may be substantially rigidly connected between the supply conduit and the inlet conduit so as to maintain the supply port and the inlet port in substantially fixed spaced relation.

The fixed support structure may define a first part of said temporary flow passage and the connector may define a second part ofthe flow passage, so that the flow passage is completed when the connector is engaged with the support structure. The support structure and connector may each define a portion of the transverse crosssection of the passage, the two portions being co-extensive along the length of the passage.

Alternatively or additionally the support structure and the connector may, when engaged together, each define different but adjacent portions of the length of the flow passage.

The support structure and connector may comprise interengageable inner and outer members, at least part of the temporary flow passage being defined by a space between the inner and outer members which is communication with the said supply and inlet ports. Preferably the connector comprises the inner member and the fixed support structure comprises the outer member.

For example, in a preferred embodiment the fixed support structure comprises a hollow housing, said supply and inlet ports opening into the interior of the housing, the connector being sealingly engaged within said housing, said flow passage then being defined between an interior surface of the housing and an exterior surface of the connector.

Preferably the housing and connector are of circular cross-section, the connector being inserted axially into the circular housing. The outer periphery of the connector and/or the inner periphery of the housing may be formed with an annular groove to define part of said flow passage. Preferably, annular resilient sealing rings are spaced axially apart on opposite sides of said groove for sealing engagement between the outer peripheral surface of the connector and the inner peripheral surface of the support structure.

The housing may be formed with an axial passage into which the connector may be inserted axially, which passage passes completely through the housing.

The connector may include a handle of substantial size which projects from the fixed support structure when the connector is engaged therewith.

The handle may be so disposed as to interfere with another function of the appliance or system into which the assembly is fitted, when the connector is engaged with the support structure, so as to encourage removal of the connector when the temporary flow passage is no longer required. For example, the projecting handle may be arranged to prevent the closing of an access hatch or panel.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a diagrammatic illustration of a prior art arrangement for temporary connection of a system to the mains supply, and Figure 2 is a sectional view of a water supply assembly according to the present invention, showing the connector in position.

Referring to the prior art arrangement of Figure 1: the mains water supply pipe 10 is provided with a stopcock 11 and the outlet port 12 of the supply pipe is spaced from the inlet port 13 of an inlet conduit 14 which is connected, within the boiler casing 15, to the return pipe 16 of the primary circuit of a central heating system. Two non retum valves 17, 18 are provided in the conduit 14 to prevent back-flow of water from the return pipe 16 along the conduit 14 to the inlet 13. A test cock 19 is provided between the non-return valves 17, 18, the appearance of water at the location of the test cock indicating that the non-return valve 17 has failed.

In order to provide for temporary connection between the mains supply pipe 10 and the inlet conduit 14, for charging or topping-up ofthe system, a flexible hose 20 may be connected between the supply port 12 and the inlet port 13 by means of suitable couplings. As previously explained, after filling or topping-up has been completed the temporary hose 20 must be removed so as to disconnect the system completely from the mains supply pipe 10.

Figure 2 illustrates one form of improved assembly in accordance with the present invention. The assembly may be formed from metal or suitable plastics or any combination of suitable materials. The nature of such materials is well known and will not be described in further detail.

The assembly comprises a supply conduit 21 for connection to the mains supply as indicated at 22. It may be directly connected to a mains supply pipe or may be connected to some other device or pipe which is coupled to the mains supply. A shutoff valve 23 is provided in the supply conduit 21 and may be operated to open up or shut off the connection to the mains supply. A right angled continuation of the conduit 21 leads upwardly from the valve 23 and then horizontally to end in a supply port 25. The supply port 25 at the end of the supply conduit 21 is sealingly engaged within an inlet passage 27 of a support structure indicated generally at 28. Abutting flanges on the supply conduit 21 and support structure 28 may be connected together by a spring clip 27a. Alternatively, the end of the conduit 21 may be connected to the inlet passage 27 by a conventional screw-threaded union.

The support structure 28 comprises a circular housing 29 forrned with a stepped axial passage 30. The inlet passage 27 opens into the interior surface of the passage 30 at the mid-point of the housing 29.

An outlet passage 31 leads from the opposite side of the housing 29 at the midpoint of the housing, at the same level as the inlet passage 27. The outlet passage 31 sealingly engages within the end of an inlet conduit 33 which leads to the primary circuit of the heating system. Abutting flanges on the outlet passage 31 and inlet conduit 33 may be connected together by a spring clip 33a, or the passage and conduit may be connected by a conventional screw-threaded union.

In similar manner to the prior art arrangement, the inlet conduit 33 incorporates two spaced non-retum valves 34, 35 and between the non-return valves is a lateral test port 36 to enable the effectiveness of the inner valve 34 to be checked. Downstream of the valve 34 the end of the inlet conduit 33 engages in a right-angled connector 32 which ends in a mounting flange 44 for connection to an inlet on the primary heating system.

The whole assembly is rigidly mounted within the boiler casing and the support structure 28 rigidly connects the supply conduit 21 to the inlet conduit 33 so that the supply port 25 is maintained in fixed spaced relation to the inlet port at the end of the inlet conduit 33.

The assembly also includes a removable connector 38 for insertion into the passage 30 which extends through the housing 29 of the support structure. The connector comprises an operating head 39 and an elongate handle 43. The head 39 is formed with an annular peripheral groove 40 on opposite sides of which are provided axially spaced 0-rings 41, 42 received in peripheral grooves in the head 39. The part of the head 39 carrying the O-ring 41 is of smaller diameter than the part carrying the 0ring 42 and the interior surface 30 of the housing 29 is similarly stepped. The purpose of this is to permit introduction ofthe head 39 into the housing 29 without the O-ring 41 being scraped over the edges of the inlet and outlet ports which open into the housing.

The back of the housing 29 is formed with an inwardly projecting peripheral flange 45 which defines a circular aperture 46. When the connector 38 is fully introduced into the housing 29, a reduced diameter portion 47 on the end of the operating head 39 projects through the aperture 46. The portion 47 of the operating head is formed with two diametrically opposed lugs 48 which pass through corresponding slots 49 in the flange 45. Subsequent rotation of the connector 38 then moves the lugs 48 away from the slots 49 so that the lugs overlie the surface of the flange 45 and retain the connector in the housing. A small fixed abutment (not shown) upstands from the flange at a location 90O from the slots 49 so that, in order to retain the connector in the housing, it may conveniently be rotated until one of the lugs 48 engages the abutment.

The passages 27 and 31 open into the interior of the housing 29 where it encircles the annular groove 40 in the head 39 when the connector 38 is fully introduced into the housing 29. The annular space between the groove 40 and the inner surface of the housing then provides a flow passage between the passages 27, 31 and hence between the supply conduit 21 and the inlet conduit 33. When the connector is in position in the housing, therefore, opening of the shut-off valve 23 will cause a flow of mains water under pressure through the assembly, past the non-return valves 34,35 and into the primary circuit of the system.

When filling or topping-up of the system has been completed, and the valve 23 has been turned off, the connector 38 is withdrawn from the housing 28 and this completely separates the supply conduit 21 from the inlet conduit 33 thus rendering it impossible for there to be any back flow of water from the primary circuit into the mains supply, even should both of the non-return valves 34, 35 fail or operate ineffectively.

The handle 43 is in the form of two elongate elements mutually at right angles.

As may be seen from Figure 2, the handle is of considerable length so as to project a comparatively long way from the assembly when the connector is in position. The projecting handle, which may be brightly coloured, thus serves as a visual reminder to the user or installer that the connector is still in position and must be removed from the housing 29 once the filling or topping-up operation has been completed. In order further to encourage removal of the handle, the assembly may be so located in relation to an access hatch in the boiler casing that the hatch cannot be closed or replaced while the connector is still in position.

The arrangement thus provides a compact and convenient assembly which may be mounted within the casing of a central heating boiler or other appliance and which allows for quick and convenient connection of the appliance to the mains supply when required, while at the same time ensuring that the subsequent disconnection eliminates any risk of back-contamination of the mains supply.

The support structure and connector arrangement described above and shown in the drawings is only one example of the ways in which the connector and support structure may co-operate in a manner to provide a temporary flow passage between the supply port and inlet port. It will be appreciated by those skilled in the art that other arrangements are possible, within the scope ofthe present invention, to achieve the same effect. For example, the inlet passage 27 of the support structure may be at a higher level than the outlet passage 31, so that should there be a back flow of water along the conduit 33 when the connector 38 is not present, such back flow is unlikely to find its way into the passage 27, and hence into the supply conduit 21. Also, instead of the flow passage being provided by a peripheral groove around the outer surface of the head 39 of the connector, it might be provided by a passage passing transversely through the interior of the body of the connector. However, the described arrangement is preferred since it does not require the connector to be introduced into the housing 29 in any particular rotational orientation.

In another alternative arrangement the support structure may comprise a solid body having internal passages which communicate with the supply conduit 21 and inlet conduit 33 respectively, and open at spaced locations on the outer surface of the support structure. The connector may then comprise an element which fits over the outer surface of the support structure so as to place the two ports into communication.

Claims

1. A water supply assembly comprising a supply conduit, for connection to a mains water supply and having a supply port, a shut-off valve in the supply conduit, an inlet conduit for connection to a water-using appliance or system, and having an inlet port spaced from said supply port, at least one valve in said inlet conduit, a support structure which is substantially fixed in relation to said supply and inlet ports, and a removable connector for detachable engagement with said support structure, the connector, when in engagement with said support structure, providing a temporary flow passage between the supply port and the inlet port.

2. An assembly according to Claim 1, wherein the valve in the inlet conduit is a non-return valve arranged to prevent the flow of water outwardly along said conduit towards said inlet.

3. An assembly according to Claim 2, wherein there are provided two non-return valves in series in the inlet conduit.

4. An assembly according to Claim 3, wherein a test port is provided between the non-return valves to enable the effective operation of the valve further from the inlet port to be checked.

5. An assembly according to any of the preceding claims, wherein the support structure is substantially rigidly connected between the supply conduit and the inlet conduit so as to maintain the supply port and the inlet port in substantially fixed spaced relation.

6. An assembly according to Claim 5, wherein the fixed support structure defines a first part of said temporary flow passage and the connector defines a second part of the flow passage, so that the flow passage is completed when the connector is engaged with the support structure.

7. An assembly according to Claim 6, wherein the support structure and connector each define a portion of the transverse cross- section of the passage, the two portions being co-extensive along the length of the passage.

8. An assembly according to Claim 6 or Claim 7, wherein the support structure and the connector, when engaged together, each define different but adjacent portions of the length of the flow passage.

9. An assembly according to any of Claims 6 to 8, wherein the support structure and connector comprise interengageable inner and outer members, at least part of the temporary flow passage being defined by a space between the inner and outer members which is communication with the said supply and inlet ports.

10. An assembly according to Claim 9, wherein the connector comprises the inner member and the fixed support structure comprises the outer member.

11. An assembly according to Claim 11, wherein the fixed support structure comprises a hollow housing, said supply and inlet ports opening into the interior of the housing, the connector being sealingly engaged within said housing, said flow passage then being defined between an interior surface of the housing and an exterior surface of the connector.

12. An assembly according to Claim 11, wherein the housing and connector are of circular cross-section, the connector being inserted axially into the circular housing.

13. An assembly according to Claim 12, wherein the outer periphery of the connector and/or the inner periphery of the housing is formed with an annular groove to define part of said flow passage.

14. An assembly according to Claim 13, wherein annular resilient sealing rings are spaced axially apart on opposite sides of said groove for sealing engagement between the outer peripheral surface of the connector and the inner peripheral surface of the support structure.

15. An assembly according to any of the preceding claims, wherein the connector includes a handle of substantial size which projects from the fixed support structure when the connector is engaged therewith.

16. An assembly according to Claim 15, wherein the handle is so disposed as to interfere with another function of the appliance or system into which the assembly is fitted, when the connector is engaged with the support structure, so as to encourage removal of the connector when the temporary flow passage is no longer required.

17. An assembly according to Claim 16, wherein the projecting handle is arranged to prevent the closing of an access hatch or panel.

18. A water supply assembly substantially as hereinbefore described with reference to Figure 2 of the accompanying drawings.