WO2003005521A1

WO2003005521A1 - Cable seal

Info

Publication number: WO2003005521A1
Application number: PCT/GB2002/003016
Authority: WO
Inventors: Christopher Cooper
Original assignee: Fibrelite Composites Ltd
Current assignee: Fibrelite Composites Ltd
Priority date: 2001-06-30
Filing date: 2002-06-28
Publication date: 2003-01-16
Anticipated expiration: 2003-12-30
Also published as: GB0116080D0

Abstract

A method of sealing comprising: taking a seal (14) comprising two disc portions (16) spaced apart axially by means of one or more spacers (18), at least one of the discs being transparent or translucent; - drilling holes (26) according to the number and location of cables (12) and the like to pass therethrough; - passing the cables (12) through the holes (26) and inserting the seal (14) into a pipe or duct (10); and filling in the space between the discs (16) with a sealant to complete the seal.

Description

CABLE SEAL

This invention relates to a method of sealing cables or the like within a pipe and to a seal member therefor, and in particular relates to the sealing of a cable-carrying service pipe or duct associated with an access chamber or sump to prevent water entering the chamber from outside or petrol or petrol fumes from entering the cable pipe or duct.

In many petrol station forecourts, petrol tanks are concealed below the ground and pipes connect the tanks to above ground electrical pump units for filling vehicles with petrol (gasoline). Pipes from the tanks usually lead, via a tank sump, to a sump under the or each petrol pump or dispenser, which are normally electrically powered. The sumps are in place to catch any overflow of fuel and prevent it being spilled into the ground. However, pipes from the tanks and any electrical connections must pass through the sump walls in order to reach the petrol pump or pumps. The pipes or ducts often carry electrical cables, conduits or the like and must be sealed so as to be fluid impervious. Indeed, regulations may call for the testing of such sumps at regular intervals by drawing a vacuum of, for example, 5 psi in order to test that no leakage is occurring. Thus, any seal must be capable of withstanding this test.

The invention provides an improved seal, and method of sealing, capable of providing a fluid- tight seal in a consistently achievable manner.

According to the present invention, there is provided a seal which comprises two disc portions spaced apart axially by means of one or more spacers, at least one of the discs being transparent or translucent.

According to a second aspect of the present invention, there is provided a method of sealing which comprises taking a seal according to the first aspect above, drilling holes according to the number and location of cables or the like to pass therethrough, passing the cables through the holes and inserting the seal into a pipe or duct, and filling in the space between the discs with a sealant to complete the seal. Since at least one of the discs is transparent or translucent, and preferably the entire seal is manufactured from a transparent material such as acrylic plastics, the operator can visibly check that the sealant has completely filled the space between the two discs in order to effect a liquid- and vapour-tight seal.

Preferably, at least one of the discs, being the transparent or translucent disc if only one is provided, has a hole to allow injection of the sealant. A blanking bolt may pass completely through the seal of the invention, which may be removed at a later date to check whether the inside of the pipe has any water or other contaminant present.

The seal of the invention is particularly useful for sealing pipes carrying cables or the like connected to sumps or access chambers on petrol station forecourts, where it is desired to seal against ingress of water and escape of petrol or petrol vapours.

Where it is desired to fit the seal of the invention to a pipe and electrical cables already in place, as opposed to a brand new installation, the "holes" drilled for the cables may in act be notches at the edges of the respective discs so that the seal can be inserted into place without the need to disconnect or cut the electrical cables.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a partial diagrammatic perspective view of a pipe or duct carrying cables with the seal of the invention;

Figure 2 is a similar view to Figure 1 on a smaller scale, showing the insertion of the seal into the pipe or duct;

Figure 3 is a perspective view of the seal;

Figure 4 is a similar view to Figure 1, showing a seal capable of being retro-fitted; and. Figure 5 is a similar view to Figure 2 of the sealed pipe of Figure 4.

Referring to the drawings, and in particular Figures 1 to 3, a pipe or duct (10) carries electrical cables (12) to a sump or access chamber associated with a petrol forecourt. A seal (14) comprises two discs (16) spaced apart by a spacer (18). The seal is cast or injection moulded from a transparent plastics material such as an acrylic material. As supplied to the user (Figure 3), the seal (14) has an injection hole (20) together with a pair of axially aligned holes (22) for receiving a blanking bolt (24). The operator then drills further holes (26) (Figure 2) as necessary in accordance with the position and number of cables (12) present. The cables (12) are then passed through the holes (26) and the seal (14) placed within the pipe (10) as illustrated in Figure 1. Finally, a sealant is injected through the injection hole (20), the progress of which can be monitored visually as the sealant can be seen through the outer transparent disc of the seal (14). When the sealant completely encircles the seal (14) and surrounds all the cables (12), the injection process can be halted. This results in a fluid-tight seal which can be consistently obtained.

Referring now to Figures 4 and 5, Figure 4 is a similar view to Figure 1 but the seal (14') has notches (26') around the periphery of the discs (16) instead of holes (26). This allows existing cables to be sealed up against the inside wall of the pipe or duct (10) without cutting or otherwise disconnecting the cables first. Once in place, the seal (14) is filled with sealant as before.

The method and seal of the invention provides a simple, economical and effective seal against water, petrol and petrol vapour in pipes or ducts in association with sumps and access chambers on petrol station forecourts.

Claims

1. A seal comprising two disc portions spaced apart axially by means of one or more spacers, at least one of the discs being transparent or translucent.

2. A seal as claimed in claim 1, wherein at least one transparent or translucent disc is manufactured from an acrylic plastic.

3. A seal as claimed in either of claims 1 or 2, wherein the entire seal is manufactured from a transparent material.

4. A seal as claimed in any one of claims 1 to 3, wherein at least one of the discs has a hole to allow injection of the sealant.

5. A seal as claimed in claim 4, wherein only one of the discs is transparent or translucent and the hole is provided in this disc.

6. A seal as claimed in any one of claims 1 to 5, wherein each of the disc portions comprises a hole for receiving a cable.

7. A seal as claimed in claim 6, wherein at least one of the cable receiving holes is a notch at the edge of the disc.

8. A seal as claimed in any one of claims 1 to 7, further comprising a blanking bolt passing through the seal.

A method of sealing comprising: taking a seal as claimed in claim 1; drilling holes according to the number and location of cables or the like to pass therethrough; passing the cables through the holes and inserting the seal into a pipe or duct; and filling in the space between the discs with a sealant to complete the seal.