GB2292778A - Pipe coupling for a hot water tank - Google Patents

Abstract

A pipe coupling has a cylindrical body member 12 with stepped bore 14, the body member having an external thread 17 at one end for engagement with a corresponding thread on a hot water tank 19 and an external thread 20 at the other end for connection to a pipe coupling. A port 35 is provided in the wall of the body member 12 and an annular collecting jacket 25 is located coaxially of the body member 12, the collecting jacket 25 having a pair of axially separated inner peripheral edges 26, 27 each edge being sealed with respect to the body 12 portion to define a chamber opening through the bore 35 into the body member 12. An outlet stub 36 is provided on the connecting jacket 25 for connection to an outlet pipe. The smaller diameter portion of the bore 14 of the main body 12 has a tubular extension 15 which extends beyond the end of the bore 14 into the tank 19. <IMAGE>

Description

PIPE COUPLING The present invention relates to a pipe coupling and in particular to a pipe coupling which permits two independent feeds to be taken off a tank, the coupling utilising a single outlet from the tank.

In domestic hot water tanks, an outlet is provided at the top of the tank to provide a connection to the hot water system and to a vent pipe. The pipe coupling in accordance with the present invention permits the use of the existing outlet from the tank to provide two independent feeds, one to the main hot water system and vent pipe and the other to a separate system, for example a power shower.

According to one aspect of the present invention a pipe coupling comprises a cylindrical body member having a stepped bore, a formation at the larger diameter end of the bore for engagement of a corresponding formation of a tank outlet and a formation at the smaller end of the bore for connection to a pipe coupling, a port being provided in the wall of the body member defining the larger diameter portion of the bore, an annular collecting jacket being located, coaxially of the body member, the annular collecting jacket having a pair of axially separated inner peripheral edges, each inner peripheral edge being sealed with respect to the body portion, one on either side of said port in the wall of the body member to define a chamber opening into the larger diameter portion of the bore of the body member via said port, an outlet stub being provided from the collecting jacket for connection to an outlet pipe, the smaller diameter portion of the bore of the main body member having a tubular extension which extends coaxially of the larger diameter portion of the bore beyond the end of the larger diameter portion of the bore.

In the pipe coupling according to the present invention, a first feed may be taken from the tank via the annular space between the extension of the smaller diameter portion of the bore of the body member and the tubular extension of the smaller diameter portion of the bore, the port in the wall of the body member, the collecting jacket and the outlet stub therefrom; and a second feed may be taken from the tank via the tubular extension and the smaller diameter portion of the bore of the body member.

The inner peripheral edges of the collecting jacket may be sealed with respect to the body member by, for example, brazing the collecting jacket to the body member. However, according to a preferred embodiment, an outwardly directed flange formation is provided on the body member intermediate of the larger and smaller diameter portions of the bore, the body member is a clearance fit with the inner peripheral edges of the collecting jacket so that the collecting jacket may be clamped between the flange formation and the outlet from the tank, sealing washers being located between the collecting jacket and the flange formation and between the collecting jacket and the outlet from the tank.In this manner, before the body member is tightened with respect to the outlet from the tank, the collecting jacket may be rotated relative thereto in order to position the outlet stub in a convenient angular location.

According to a further preferred embodiment of the invention, the outlet stub is offset from the centre line so that the axial position of the outlet stub relative to the body member may be adjusted by inverting the collecting jacket with respect to the body member.

An embodiment of the invention is now described, by way of example only, with reference to the accompanying drawings in which: Figure 1 illustrates in cross-section a pipe coupling in accordance with the present invention; and Figure 2 illustrates in side elevation, the pipe coupling illustrated in Figure 1.

As illustrated in Figures 1 and 2, a pipe coupling 10 has a cylindrical body member 1 2 with stepped bore 13, having a larger diameter portion 14 and smaller diameter portion 1 5. An hexagonal flange formation 16 extends outwardly from the body member 12 at the junction between the larger diameter portion 1 4 and smaller diameter portion 1 5 of bore 1 3.

An external thread formation 17 is provided at the end of the body member 1 2 defining the larger diameter portion 14 of bore 13, for engagement of corresponding thread on an outlet 1 8 located at the top of a domestic hot water tank 1 9. An external thread formation 20 is also provided at the end of the body member 1 2 defining the smaller diameter portion 1 5 of bore 13, for engagement of a corresponding thread of a pipe coupling, by which a first outlet pipe may be connected to the coupling 10.

An annular collecting jacket 25 has a pair of axially separated inner peripheral edges 26 and 27. The collecting jacket 25 locates over the portion of the body member 12 defining the larger diameter portion 14 of bore 13, so as to define a chamber 28 around the body member 1 2.

Sealing rings 30, 31 are provided between the flange formation 16 and the collecting jacket 25 and between the collecting jacket 25 and the end of the body member 1 2 defining the larger diameter portion 14 of bore 13, so that when the body portion 12 is screwed into the outlet 18 from the tank 1 9 to clamp the collecting jacket 25 between the flange formation 16 and outlet 18, the sealing rings 30, 31 will be compressed to seal the collecting jacket 25 with respect to the body member 1 2. The sealing rings 30, 31 may be made of any resilient material, for example fibre or elastomeric rings may be used.

A series of ports 35 are provided in the wall of the body member 1 2 which is surrounded by the collecting jacket 25, so as to provide a connection between the chamber 28 and the larger diameter portion 14 of bore 13.

An outlet stub 36 is provided from the collecting jacket 25. The axis of stub 36 is offset from the centre line between the axially spaced inner peripheries of the collecting jacket 25. The outlset stub 36 is provided with an external thread formation for engagement of a pipe coupling by means of which it may be connected to a second outlet pipe.A tubular extension 40 is a press fit within the smaller diameter portion 1 5 of bore 13, the outer end 41 being flared into abutment with the end of the body member 12, defining the smaller diameter portion 1 5 of bore 1 3. The other end 42 of the tubular extension 40 extends 100 to 200 mm below the end of the body member 12, defining the larger diameter portion 1 4 of bore 1 3. The diameter of the tubular extension 40 is increased at a position below the end of the body member 1 2.

To assemble the pipe coupling 10, the collecting jacket 25 is located over the body member 12, between the flange formation 16 and thread formation 17, the sealing ring 30 being located between the collecting jacket 25 and flange formation 1 6. The collecting jacket 25 may be positioned either way up relative to the body portion 12, in order to adjust the axial position of the outlet stub 36.

The body member 1 2 is then screwed into the outlet 1 8 of tank 19, with the sealing ring 31 between the collecting jacket 25 and outlet 18.

Before finally tightening the body member the collecting jacket 25 may be rotated to locate the outlet stub 36 at an appropriate angular position.

The body member 1 2 may then be tightened by means of a spanner which engages the external flange 16, to clamp the collecting jacket 25 between the flange 16 and outlet 18 also compressing rings 30, 31 to seal the collecting jacket 25.

The pipe coupling 10 thus provides two feeds; a first via the annular space between the wall of the body member 1 2 defining the larger diameter portion 14 of bore 13 and the tubular extension 40, ports 35, the chamber 28 defined by the collecting jacket 25 and outlet stub 36; and the second via tubular extension 40 and the smaller diameter portion 15 of bore 13.

In domestic hot water tanks air bubbles entrapped in the water will rise to the top of the tank and will be able to leave the tank via the larger diameter portion 14 of bore 13, ports 35, chamber 28 and outlet stub 26.

The normal hot water circuit and vent pipe may consequently be connected to the tank 1 9 via outlet stub 36.

Water drawn from lower in the tank via the tubular extension 40 will have a reduced amount of entrapped air and would consequently be suitable for power shower systems where entrapped air may cause serious problems to the operation of certain designs of water pump. It may however also be desirable to provide a vent pipe for the secondary system connected to the smaller diameter portion 1 5 of bore 1 3.

Various modifications may be made without departing from the invention.

For example, while in the above embodiment the outlet stub 36 is adjustable both axially and angularly with respect to the body member 12, it may alternatively be fixed in one or both dimensions. In the latter case, the collecter jacket 25 may be secured and sealed with respect to the body member 1 2 by, for example, brazing. Furthermore, the tubular extension 40 may be formed integrally of the body member 1 2.

The thread formations on the end of body member 1 2 defining the smaller diameter portion 1 5 of bore 1 3 and on the outlet stub 36 may be replaced by any other formation by which an outlet pipe may be attached thereto.

The thread formation 1 7 may also be replaced with other formations complimentary to the interengaging formation on the outlet 1 8 from tank 1 9 or an adaptor therefor.

To avoid entrapped air entering the tubular extension 40 as it rises to the top of the tank 19, the end of the extension 40 may be closed and one or more ports provided in the side wall of the extension.

The coupling in accordance with the present invention may also be used in secondary return circuits where liquid tapped off from the tank via outlet stub 36 is returned via the smaller diameter portion 1 5 of bore 1 3 and extension tube 40. In this case, the length of the extension tube 40 may be increased to re-enter the liquid at a lower point in the tank.

Claims (9)

1. A pipe coupling comprising a cylindrical body member having a stepped bore, a formation at the larger diameter end of the bore for engagement of a corresponding formation of a tank outlet and a formation at the smaller end of the bore for connection to a pipe coupling, a port being provided in the wall of the body member defining the larger diameter portion of the bore, an annular collecting jacket being located, coaxially of the body member, the annular collecting jacket having a pair of axially separated inner peripheral edges, each inner peripheral edge being sealed with respect to the body portion, one on either side of said port in the wall of the body member to define a chamber opening into the larger diameter portion of the bore of the body member via said port, an outlet stub being provided from the collecting jacket for connection to an outlet pipe, the smaller diameter portion of the bore of the main body member having a tubular extension which extends coaxially of the larger diameter portion of the bore beyond the end of the larger diameter portion of the bore.

2. A pipe coupling according to Claim 1 in which prior to assembly, the annular collecting jacket is rotatable relative to the cylindrical body member so that the angular position of the outlet stub may be adjusted relative to the body member.

3. A pipe coupling according to Claim 2 in which the annular collecting jacket is clamped between a flange formation on the body member and the tank outlet.

4. A pipe coupling according to Claim 3 in which sealing rings are provided between the flange formation and the collecting jacket and between the collecting jacket and the tank outlet, to seal the collecting jacket.

5. A pipe coupling according to any one of the preceding claims in which the axis of the outlet stub from the collecting jacket is offset from the centre line between the inner peripheral edges of the collecting jacket, the collecting jacket being reversible relative to the body member to adjust the axial position of the outlet stub.

6. A pipe coupling according to any one of the preceding claims in which a plurality of ports are provided in the portion of the body member defining the larger diameter portion of the bore to provide a connection between the larger diameter portion of the bore and the collecting jacket.

7. A pipe coupling according to any one of the preceding claims in which the extension of the smaller diameter portion of the bore comprises a tubular member which is a press fit within the smaller diameter portion of the bore, the end of the tubular member being flared into engagement with the end of the body member defining the smaller diameter portion of the tubular bore.

8. A pipe coupling as claimed in any one of the preceding claims in which the end of the tubular extension which extends beyond the end of the larger diameter portion of the bore of the body member, is closed, ports being provided in the side wall of the tubular extension.

9. A pipe coupling substantially as described herein with reference to, and as shown in Figures 1 and 2 of the accompanying drawings.