GB2194981A - Service chamber for underground stopcock housing - Google Patents

Abstract

A service chamber for an underground stopcock housing comprises a base (10) which engages the stopcock and its associated pipe and is connected to a corrugated tube (11) which extends upwardly from the base and which interlocks with the surrounding ground. In this way, torque applied to, say, the stop cock is resisted by the ground via the base and the tube. This prevents the pipe being damaged as a result of the application of such torque, for example, on opening or closing of the stop cock or on removal of a valve assembly of the stop cock for its replacement by a water meter.

Description

SPECIFICATION Service chambers The invention relates to service chambers to be buried in the ground at a device, such as a stop cock or a valve, which is fitted in a buried pipe and which in disassembly or use is subjected to a torque about an axis normal to the length of the pipe. The invention is particularly applicable to the replacement of stop cocks by water meter assemblies in water pipes, but is equally applicable to the same or other devices in gas and other fluid conveying pipes.

Such devices are usually attached to the pipe, and/or operated, by rotation of the device or a part of the device about an axis normal to the length of the pipe. This is done by a tool carried at the end of a rod and operated from above the ground. It is a disadvsntage that the torque applied to the device in removing or replacing the device or in operating the device can be sufficient to twist the pipes. This can cause the pipes to fracture and may also cause leaks around joints in the pipes. This is plainly undesirable.

According to the invention, there is provided a service chamber to be buried in the ground at a device, such as a stop cock or a valve, which is fitted in a buried pipe and which in disassembly or use is subjected to a torque about an axis normal to the length of the pipe, and comprising a base plate for engagement with the pipe, a tube fixed to the base and extending upwardly therefrom and an upper section closing an end of the tube remote from the base plate and providing a lid for access to a chamber formed by the tube, the tube being provided with a shaped surface which forms an interlock with the surrounding ground to resist, via the base, twisting of the pipe on the application to the device of torque about an axis normal to the length of the pipe.

Thus, by locking the base to the pipe, locking the tube to the base and then locking the tube to the ground, a restraining force is provided on the pipe which prevents the pipe being rotated when torque is applied to the device about an axis normal to the length of the pipe. This would, of course, not be the case if the tube had a smooth surface, which would allow the tube to rotate with the pipe.

Preferably, the tube is provided with corrugations which extend circumferentially around the pipe. Alternatively, the tube may be provided with corrugations which extend axially.The corrugations may be of square crosssection.

Alternatively, the tube may be provided with shaped projections or shaped recesses or both.

The tube may be a single walled tube or a double walled tube.

The base and the tube may be formed in one piece or may be formed sepsrately and then joined together. The join may, for example, be by glue or solvent welding.

Preferably, the base is provided with an elongate channel of generally U-shaped crosssection into which the pipe is received.

The channel may be fit under the pipe or may fit over the pipe.

The tube may be of circular cross-section or any other convenient cross-section.

The following is a more detailed description of one embodiment of the invention, by way of example, reference being made to the accompanying drawing which is a schematic perspective view of a service chamber.

The service chamber comprises a base plate 10, a tube 11 and an upper section 12.

The base plate 10 is generally an inverted dish shape with s flange 13, a wall 14 and an upper surface 15. A U-section channel 16 is formed in the upper surface 15 and extends diametrically across the base plste 10. The channel 16 is provided with a widened recess 17 for a purpose to be described below. The bsse plate is formed from a plastics material.

The tube 11 is also formed from plastics material and is provided with circumferentially extending corrugations 18 of rectangular corss-section. The minimum diameter of the tube is equsl to the diameter of the wall 14 of the base member, so that the tube is a push-fit over the base member to engage against the flange 13.

The upper section 12 is also formed from a plastics material and is in the shape of an inverted dome with a cast iron lid 19 and frame 20 inset into its upper end. The diameter of the lower, open, end of the upper section 12 is greater than the maximum diameter of the tube 11, so that the tube 11 can extend into the upper section 12.

The use of the service chamber described above with reference to the drawing will now be described in relation to the fitting of a water meter assembly into a water pipe provided with a stop cock hsving a body keyed into the pipe and having a valve assembly in screw threaded engagement with the body so that the valve assembly can be removed by its rotation about an axis normal to the length of the pipe. In one method of fitting a water meter assembly in such a water pipe, the valve assembly is unscrewed from the body and a water meter assembly in screwed into the body.

In use in such a method, the service chamber described above with reference to the drawings is assembled as follows. First, the ground around the pipe and the stop cock is dug away. Then, the base plate 10 is inserted beneath the pipe at the stop cock so that the pipe fits in the U-section channel 16 and the stop cock body sits in the widened recess 17. The upper surface 15 of the base plate is arranged generally horizontally.

Next, the tube 11 is fitted over the base plate until its lower end engages the flange 13. The two parts are then connected either by gluing or by solvent welding. The tube 11 can be cut to any required height in accordance with the depth of the pipe beneath the ground.

The hole is then back-filled and the ground packed around the tube so that the ground enters into the corrugations.

The valve assembly is then removed from the body by unscrewing (i.e. the application of torque to the valve assembly), using a suitable tool at the end of a rod. The torque imposed on the pipe as a result of such unscrewing is resisted by the ground via the tube corrugations 18 and the base plate -10. Accordingly, the pipe does not twist and therefore suffers no damage.

After removal of the valve assembly, a meter assembly can be screwed into the body to be contained within the chamber formed by the tube 11. The torque generated on the pipe by final tightening of the meter assembly is again resisted by the ground via the base plate 10 and the tube 11, so that again the pipe is not damaged.

The upper section is then fitted over the tube to sit on the compacted back-filled ground and does not contact the tube 11.

The footway or surrounding surface is then made good to the level of the frame 20.

As well as resisting the torque, the corrugated tube 11 has other advantages. First, any load imposed at the head of the tube 11 is dissipated to the ground, rather than being transmitted direct to the base plate 10 as would be the case for a smooth tube. Secondly, the corrugations 18 can concertina to absorb shock loads without movement of the base plate 10. Further, the corrugations can allow the tube to expand and contract in ground upheaval situations without upward or downward movement of the base plate 10 and consequently wjthout upward or downward movement of the pipe (which might cause pipe damage).

Although the tube 11 has been described above with reference to the drawing as having circumferentially extending corrugations 18 of rectangular cross-section, it will be appreciated that the tube may be provided with any kind of shaped surface which forms an interlock with the surrounding ground to resist the twisting forces generated, For example, the tube 10 may be provided with axially extending corrugations or spirally extending corrugations. The corrugations can be of any convenient section.

Instead of corrugations, shaped projections and/or depressions could be used.

It will also be appreciated that, although the tube 11 shown in the accompanying drawing is of circular cross-section, the tube 11 may be of any convenient cross-section. It could be oval or elliptical or be provided with corners.

It will also be appreciated that the base plate 10 and the upper section 12 need not be as described above with reference to the drawing. All that is required of the base plate is that it be integral with or connectable to the tube 11 and be capable of being locked onto the pipe in such a way that torque on the pipe about an axis normal to the pipe is transmitted to the base plate. Thus, the base plate may be provided with channel of inverted U-section which fits over the pipe (rather than under the pipe as is the case with the U-section channel 16 shown in the drawing).

The upper section can be of any desired configuration.

In the example given above, the service chamber has been used in the replacement of a stop cock with a water meter. It will be appreciated, however, that such a service chamber can be used where a stop cock is being instslled, to resist the torque generated on the opening and closing of the stop cock.

In addition, it could be installed at any point along a pipe where a device is located whose operation and/or removal and/or replacement generates torque about an axis normal to the length of the pipe. For example, the service chamber may be used in connection with a valve in a gas pipe or any other such device in any fluid pipe buried in the ground.

Claims (13)

1. A service chamber to be buried in the ground at a device, such as a stop cock or a valve, which is fitted in a buried pipe and which in disassembiy or use is subjected to a torque about an axis normal to the length of the pipe, and comprising a base plate for engagement with the pipe, a tube fixed to the base and extending upwardly therefrom, and an upper section providing a closure for an end of the tube remote from the base plate and providing a lid for access to a chamber formed by the tube, the tube being provided with a shaped surface which forms an interlock with the surrounding ground to resist, via the base, twisting of the pipe on the application to the device of torque about an axis normal to the length of the pipe.

2. A service chamber according to claim 1 wherein the tube is provided with corrugations which extend circumferentially around the pipe.

3. A service chamber according to claim 1 wherein the tube is provided with corrugations which extend axially.

4. A service chamber according to claim 2 or claim 3 wherein the corrugations are of square cross-section.

5. A service chamber according to claim 1 wherein the tube is provided with shaped projections or shaped recesses or both.

6. A service chamber according to any one of claims 1 to 5 wherein the tube is a single walled tube.

7. A service chamber according to any one of claims 1 to 5 wherein the tube is a double walled tube.

8. A service chamber according to any one of claims 1 to 7 wherein the base and the tube are formed in one piece.

9. A service chamber according to any one of claims 1 to 7 wherein the base and the tube are formed separately and then joined together.

10. A service chamber according to any one of claims 1 to 9 wherein the base is provided with an elongate channel of generally U-shaped cross-section into which the pipe is received.

11. A service chamber according to claim 10 wherein the channel fits under the pipe.

12. A service chamber according to claim 10 wherein the channel fits over the pipe.

13. A service chamber substantially as hereinbefore described with reference to the accompanying drawings.