GB2204077A - Prefabricated chamber for use underground to house pipes and fittings - Google Patents

Abstract

There is disclosed a prefabricated chamber 10 intended for subterranean use with a water supply pipe in order to control the rate of flow, to monitor the volume of flow, or to inspect the pipe. Preferably, the chamber is a water meter, and comprises a cylindrical housing 11 for substantially uniform cross section throughout its height and open at its upper end 12, the housing being intended to be positioned below ground level and to accommodate a water flow control or monitoring device. A removable cover 15 is provided, and a walled enclosure 18 carries the cover assembly 15 at its upper end and is mounted at its lower end on the upper end of the housing 11. The housing 11 is made of plastics material and comprises a rigid double walled and externally corrugated construction, and the walled enclosure 18 is slidably mounted on the upper end of the housing 11 to vary the vertical spacing of the cover from the upper end of the housing to bring the cover 17 to a required position relative to ground level. <IMAGE>

Description

DREFABRICATED CHAMBER FOR USE UNDERGROUND This invention relates to a prefabricated chamber of the type for use below ground and with an underground water pipe in order (a) to control the rate of flow, (b) to monitor the volume of flow, or (c) to inspect the underground pipe, such a chamber being referred to hereinafter as "a prefabricated chamber of the type specified".

One example of use of a prefabricated chamber of the type specified is as a water meter chamber (in order to monitor the volume of flow), in which a water meter will be housed in the chamber below ground level, access to the meter for "reading" purposes being derived by opening or lifting an upper closure member of the chamber. There is an increase in demand for water meter chambers, in view of the wish of many consumers to be charged according to actual volume of water consumption, as opposes to z an flat rate charge regardless of consumption.

There is also a growing need for prefabricated chambers which can be used as access chambers to control, or to inspect the flow along an underground pipe.

It is a requirement for a prefabricated chamber of the type specified that it can be readily installed, has sufficient strength and durability to withstand earth loadings, and environmental factors tending to cause deterioration in the fabric of the chamber. Ease and relative cheapness of manufacture, and simple assembly on site are also important considerations.

The invention therefore seeks to provide a simple, but robust construction of prefabricated chamber of the type specified, and which can be manufactured readily at reasonable cost.

According to the invention there is provided a prefabricated chamber of the type specified which comprises: a housing of substantially uniform cross-section throughout its height and being open at its upper end, the housing being intended to be positioned below ground level and to accommodate a water flow control or monitoring device; a removable cover intended to be located at ground level; and, a walled enclosure carrying said cover at its upper end and mounted at its lower end on said upper end of the housing; in which: the housing is made of plastics material and comprises a rigid double walled and externally corrugated construction; and, the walled enclosure is slidably mounted on the upper end of the housing to vary the vertical spacing of the cover from the upper end of the housing to bring the cover t a required position relative to ground level.

Thus, a prefabricated chamber of the type specified according to the invention has necessary strength and rigidity to withstand loadings encountered in use, by virtue of the rigid double walled corrugated construction of the housing, and also has the advantage that the air gap defined between the two walls of the housing act as a thermal insulating layer which therefore reduces the rate of transfer of heat between the interior of the housing and the surrounding sub-soil, in order to reduce the risk of pipes, or devices having water flowing through them, from freezing-up in very cold ambient conditions.

The capability of raising or lowering the walled enclosure means that accurate positioning of the level of the housing in an excavated hole is not necessary, in that the enclosure can be upwardly or downwardly adjusted to bring the cover to the required position relative to ground level.

Embodiments of prefabricated chamber according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded view of the component parts of a first embodiment of prefabricated chamber for subterranean use; Figure 2 is a diagrammatic side view of a chamber according to the invention in use as a subterranean meter chamber; Figure 3 is a diagrammatic side view of an embodiment of chamber according to the invention in the form of a subterranean valve access chamber; Figure 4 is an enlarged side view corresponding to Figure 2; Figure 5 is a side view of the upper portion of a subterranean chamber according to the invention; Figure 6 is a plan view corresponding to Figure 5; Figure 7 is an exploded view of a "goose neck" pipe fitting for use within a chamber according to the invention; and, Figure 8 is an exploded view of a "goose neck" fitting for use in a chamber according to the invention.

Referring now to Figure 1 of the drawings, there is shown a prefabricated chamber of the type intended for subterranean use, the chamber being to be used with a water supply pipe in order (a) to control the rate of flow (b) to monitor the volume of flow or (c) to inspect the pipe. In Figure 1, there is shown a subterranean chamber for use as a water meter chamber.

The chamber is designated generally by reference 10 and comprises a cylindrical housing 11 of substantially uniform cross-section throughout its height and open at its upper end 12. The housing 11 is positioned in an excavated hole below ground level 13, and is intended to accommodate a water control or monitoring device which, in the illustrated embodiment, comprises a water meter 14.

A cover assembly 15 is arranged at ground level, and comprises a cast iron frame 16 and a removable cover of ductile iron 17. The underside of the cover or lid 17 may be fitted with insulation material, in which case recesses may be required to be formed in the lid.

The frame 16 is carried at the upper end of a walled enclosure 18 which is made of plastics material, and which is slidably mounted at its lower end in telescopic manner on the upper end of the housing 11. The enclosure 18 effectively takes the form of a "top hat" section, and it can be vertically adjusted relative to the housing 11, so as to bring the cover assembly 15 generally in line with the ground level 13.

The housing 11 is cylindrical, and is of double walled construction. One particularly suitable construc'lon is a double walled and externally corrugated pipe available from Aqua-pipes Limited. Thus, the housing 11 is a double walled moulding of plastics material, having an inner liner which is cylindrical, and therefore provides a smooth interior surface to the housing 11, and has an outer liner which is corrugated, to impart strength and rigidity to the construction.

The slidable mounting of the walled enclosure 18 on the housing 11 enables the vertical spacing of the cover assembly 15 from the upper end of the housing 11 to be adjusted to bring the cover to a required position relative to ground level.

The assembled components of the subterranean chamber can then be securely located in position, after the required level has been reached for the cover portion, by application of "back-fill". The assembly has sufficient strength and rigidity to withstand such loadings.

In addition, by forming the housing 11 of double walled construction, an air gap is defined between the two walls, and this acts as a thermal insulating layer which therefore reduces the late of transfer of heat between'the interior of the housing and the surrounding sub-soil, in order to reduce the risk of the pipes, or devices having water flowing through them, from freezing-up in very cold ambient conditions.

In Figure 1, there is shown use of the subterranean chamber as a water meter chamber, having a water meter 14 provided therein, and an inlet pipe 19 is taken through a hole in the lower end of the wall of the housing 11, and passes upwardly through a control tap 20 which controls the flow through the water meter 14 and then exits via outlet pipe 21, also taken through a hole or archway cut in the lower end of the wall of the housing 11.

The double walled housing 11 is conveniently moulded from polybutylene, and if a particular length of housing pipe is too tall, appropriate lengths can readily be cutoff using a saw or similar. This further permits the composite assembly to take up any required overall height to suit particular ground conditions.

Figure 2 also shows the embodiment of Figure 1, but in a more schematic view, in which water meter 14 is secu-rely located in position, in combination with the inlet and outlet pipe fittings, by means of a brace bar 22 which extends acros-s the interior of the housing 11. This provides a very simple, but reliable construction, which can be obtained much more cheaply than existing arrangements in which platforms of substantial construction are erected in the interior of a water meter chamber.

The invention is not limited to use as a water meter chamber, and Figure 3 shows a modified embodiment, designated generally by reference 30, which is intended for use as a valve access chamber, in combination with an underground piped water supply 31.

Figure 4 is a schematic view, corresponding to Figure 1 and 2, showing how the entry and exit pipes can be taken into the interior of the chamber via cut-outs 32. Parts corresponding with those already described are designated by the same reference numerals, and will not be described in detail again.

Figures 5 and 6 show detail of the cover assembly 15 of the subterranean chamber according to the invention.

Figure 7 shows a goose neck outlet for incorporation within the chamber, and Figure 8 shows a goose neck inlet which may form part of a pipe fitting for incorporation within the chamber.

The two sizes envisaged at present for the chamber will be 200 mm and 300 mm diameter.

The metal frame and cover can be formed of cast iron or ductile iron, and may be bolted and possibly bonded to the top hat section. Ductile iron would be preferable for strength and relatively lower weight. The lids may be drop-in or of the hinged type. On the 200 mm size, this could be a 200 mm by 200 mm clear opening cast iron hinged type of lid. On the 300 mm size, this could be a 250 mm by 200 mm or 300 mm by 150 mm ductile iron drop-in type. The top hat section may be manufactured from moulded polyethylene, though other plastics materials could be used, or glass reinforced plastics (GRP).

By arranging the upper section to be telescopic over the lower or base section, this allows adjustment of height in simple manner, and ensures surface loads are supported by back fill, and not by the base section. The use of polyethylene is preferred, because it has a reasonable strength, but also has inherent flexibility which reduces the risk of fractures.

The double walled housing is made of polypropylene, or possibly polyethylene, and the corrugations formed in the external surface can be used as a guide for cutting, if a shorter height chamber is required. Because the corrugations are sealed, and hollow, they contain air, and this improves the insulation properties of the chamber.

Slots for pipe entry can readily be cut in the base section to customer requirement.

As described above, a brace bar 22 may be provided to support the pipe fittings and the water meter within the chamber. This brace bar can be of plastics construction and enables, with the use of goose neck setters, all pipe connections to be contained within the chamber and to be available for visual inspection. Also, the goose neck s-etter can be connected to the pipes first, and the base section chamber placed over the installation, thereby eliminating difficult connections within a confined area.

The completed installation can then be strapped to the brace bar for support by plastics cable ties. The brace bar will be fitted through holes drilled in the wall of the housing. It can be retained using half inch and three quarter inch PVC pipe. The half inch pipe will form the brace bar and short lengths (half inch) will be cut from the three quarter inch size. The internal diameter of the tee quarter inch pipe is a good sliding fit-over the outer diameter of the half inch pipe. These can then be solvent-cemented in place. If the customer requires the option of fitting the brace bar on site, this can be achieved by drilling a hole through the brace bar, and fitting a brass split pin which retains that end of the brace bar.

Both sizes of chamber will be multifunction, and can be used for meter applications or access chambers to other equipment.

Claims (7)

1. A prefabricated chamber of the type specified which comprises: a housing of substantially uniform cross-section throughout its height and being open at its upper end, the housing being intended to be positioned below ground level and to accommodate a water flow control or monitoring device; a removable cover intended to be located at ground level; and, a walled enclosure carrying said cover at its upper end and mounted at its lower end on said upper end of the housing; in which: the housing is made of plastics material and comprises a rigid double walled and externally corrugated construction; and, the walle-d enclosure is slidably mounted on the upper end of the housing to vary the vertical spacing of the cover from the upper end of the housing to bring the cover to a required position relative to ground level.

2. A chamber according to Claim 1 and adapted for use with an underground water pipe, including means for controlling the rate of flow of water in said pipe.

3. A chamber according to Claim 1 and adapted for use with an underground water pipe, including means for monitoring the volume of flow in said pipe.

4. A chamber according to Claim 1, a-nd in the form of a water meter chamber.

5. A chamber according to any one of the preceding claims, including pipe work and pipe fittings mounted externally of the housing.

6. A chamber according to Claim 1 and adapted for use with an underground pipe, and in the form of a valve access chamber.

7. A chamber according to Claim 1 and substantially as hereinbefore described with reference to, and as shown in any one of the embodiments illustrated in the accompanyind drawings.