GB2206666A

GB2206666A - Expansion absorbing device

Info

Publication number: GB2206666A
Application number: GB08716013A
Authority: GB
Inventors: Leslie Ricketts; John-Mosse Brian St
Original assignee: ST JOHN MOSSE BRIAN
Current assignee: ST JOHN MOSSE BRIAN
Priority date: 1987-07-08
Filing date: 1987-07-08
Publication date: 1989-01-11
Also published as: GB8716013D0

Abstract

An expansion absorbing device for connection in a water supply line comprising a cylindrical housing 1 formed of plastics or non-ferrous metal, and a cylindrical body 2 contained within the housing and having an axial bore 3 therethrough communicating with ports 4 in the end walls 5 of the housing. The body 2 is made of resiliently compressible and water impervious material such as foamed or expanded plastics or rubber with internal pockets of air in a honeycomb formation. The body 2 will become compressed under freezing conditions to absorb expansion and thereby to prevent excessive pressures being built up in the supply line. The ports 4 may be connected by compression joints to a pipe. <IMAGE>

Description

EXPANSION ABSORBING DEVICE The invention relates to an expansion absorbing device for connection in a water supply line. The device described herein is designed to be fitted into a mains water pipe so as to allow expansion of water due to freezing conditions and thus prevent the bursting of pipes. When water freezes in supply pipes it expands and causes a build up of pressure which if not relieved, can lead to the bursting of the pipe or to the failure of joints in the pipe line. The object of the present invention is to provide a device which can be fitted into a supply line and which will absorb expansion caused by freezing and prevent the build up of pressures in the supply line.

According to the present invention there is provided an expansion absorbing device for connection in a water supply line comprising a cylindrical housing; contained within the housing a cylindrical body having an axial bore therethrough; and ports in the end walls of the housing communicating with the bore in the cylindrical body; wherein the body is made of a resiliently compressible and water impervious material.

An embodiment of the invention is described below with reference to the accompanying drawing, Figure 1, which shows a longitudinal cross section through a device according to the invention.

The expansion device as shown in Figure 1 consists of a cylindrical housing 1 which may be made from plastics such as polypropylene or from non-ferrous metal such as copper or brass. A cylindrical body 2 contained within the housing has an axial bore 3 therethrough. Ports 4 in the end walls 5 of the housing communicate with the bore 3 in the cylindrical body 2. The ports 4 can be connected by compression joints or soft soldered joints to the pipes of a water supply line.

The cylindrical body 2 is formed from a resiliently compressible and water impervious material. For example, it may be made of rubber containing air pockets in a honeycombe or may be made of foamed or expanded plastics material. As shown, the body 2 completely fills the space within housing 1 but this is not essential. In the case where the body is made from a preformed tube of foamed or expanded plastics material there may be some clearance between the body 2 and the inside of the housing 7.

The physical characteristics of the body 2 will be such that it will maintain its relaxed dimensions at normal operating pressure, such as about 40 psi in domestic water supplies, will be compressed at substantially higher pressures, such as 80 psi, to allow for expansion in the water supply system caused by freezing of the water, and will return to its original dimensions when the pressure returns to normal. The specification of the material may be adapted to suit systems operating at various water pressures, and will begin to compress at pressure substantially higher than normal working pressures, but well below pressures at which damage to the supply system or failure of any joint therein is likely to occur. Naturally the body 2 should be made from non-toxic materials.

The size of the device can be varied in proportion to the length of the pipe being protected but in the case of an extremely long pipe run, local freezing conditions may prevail along the pipe thereby requiring more than one device where the combined expansion facilities add up to the total expansion required to avoid bursting of the supply pipe or failure of any joints therein.

The body 2 may be formed within the housing 1 by injection of plastics material. In this case the bore may be provided by using a withdrawable mandrel or may be cut through the body after setting of the plastics material.

Claims

1. An expansion absorbing device for connection in a water supply line comprising a cylindrical housing; contained within the housing a cylindrical body having an axial bore therethrough; and ports in the end walls of the housing communicating with the bore in the cylindrical body; wherein the body is made of a resiliently compressible and water impervious material.

2. A device as claimed in claim 1 wherein the cylindrical body is made of foamed or expanded plastics material.

3. A device as claimed in claim 1 wherein the cylindrical body is made of rubber containing air pockets in a honeycomb formation.

4. An expansion absorbing device substantially as described herein with reference to the accompanying drawing.