GB2246828A

GB2246828A - Improvements relating to pipe closure devices

Info

Publication number: GB2246828A
Application number: GB9017630A
Authority: GB
Inventors: Peter Alden
Original assignee: PIPE EYE VISION Ltd
Current assignee: PIPE EYE VISION Ltd
Priority date: 1990-08-10
Filing date: 1990-08-10
Publication date: 1992-02-12
Also published as: GB9017630D0

Abstract

The pipe closure device is constructed from two main parts namely a support structure 1 and a tubular member 2. The structure is suspended from a cable 3 by means of which it may be lowered into a manhole to enable the tubular member 2 to be introduced into a section of pipeline. The forward end of the tubular member 2 carries a skirt 4 in the form of an expandable tube. This tube will be expanded to create a good seal with the wall of the pipe, into which the tubular member 2 has been introduced, through a pneumatic or hydraulic supply line 5. Once this seal has been achieved a sluice gate 8 will be operated (by a hydraulic or pneumatic supply line 7) so as to be lowered to close off the tubular member 2, thus blocking the flow of water through the pipeline. <IMAGE>

Description

'f,Improvements relating to Pipe Closure Devices" Problems are experienced in achieving a cut-off of flow through underground pipes (such as water supply or sewerage pipes). Often these pipes can be accessed via manholes located at intervals along the pipeline and if the pipe can be blocked at one end of a section leading to a manhole, inspection equipment can be introduced from a point downstream which can then examine the status of the pipeline, clean it, or carry out any other required operations.

However, the closing-off of the pipeline presents great difficulties due to the pressure of the head of water which builds up once any attempt is made to block the pipe.

According to the present invention there is provided a pipe closure device comprising a sluice gate on a support and a tubular member for insertion into the pipe and projecting from one side of the support and aligned with the sluice gate opening, the tubular member having an external flexible sealing skirt which will adjust to seal the gap between the pipe and the tubular member.

With such an arrangement the closure device can be introduced into a pipeline section without substantially impeding the flow of water passing through the pipeline until such time as an adequate seal is achieved between the pipeline and the tubular member. The sluice gate can then be closed so as to shut off the downstream section of pipe with a fair certainty that there will be only a minimal leakage of water into that pipe section. Once operations on that section of pipe have been completed the sluice gate will be opened so as to relieve the pressure of the head of water and once the water level has returned to normal, the pipe closure device can relatively easily be removed.

The sealing skirt can just be an annular flap or ring of flexible material (such as rubber) in which case ideally the skirt will taper towards the free end of the tubular member so that it may be progressively brought into a sealing relationship with the pipe wall. A more positive arrangement may be achieved by providing that the skirt is expandable by expansion means to seal the gap between the pipe and the tubular member. Thus the skirt could be in the form of a tyre, with or without an inner tube.

If the tubular member is detachably mounted onto the support it could be replaced by a similar tubular member designed for a pipe with a different internal diameter, for use with the same sluice gate and support. The tubular member could also have an elongate extension section between the support and the skirt so that the portion incorporating the skirt can be introduced into a section of the pipe which is of the smaller diameter of a stepped opening to that pipe section.

Ideally the powered operating means will form part of the closure device for raising and lowering the sluice gate.

This could be achieved by hydraulic or pneumatic rams or by screw arrangements, for example.

The invention may be performed in various ways and one preferred embodiment will now be described, by way of example, and with reference to the accompanying drawings in which: Figure 1 is a sideview of a pipe closure device of this invention; and Figure 2 is a front perspective view of the device shown in Figure 1.

The pipe closure device is constructed from two main parts namely a support structure 1 and a tubular member 2.

The structure is suspended from a cable 3 by means of which it may be lowered into a manhole to enable the tubular member 2 to be introduced into a section of pipeline. The forward end of the tubular member 2 carries a skirt 4 in the form of an expandable tube. This tube will be expanded to create a good seal with the wall of the pipe, into which the tubular member 2 has been introduced, through a pneumatic or hydraulic supply line 5. Once this seal has been achieved a sluice gate 6 will be operated (by a hydraulic or pneumatic supply line 7) so as to be lowered to close off the entry end 8 of the tubular member 2, thus blocking the flow of water through the pipeline.

With the pipeline blocked off by the expandable skirt 4 and the sluice gate 6 the section of the pipeline downstream of the closure device can be inspected, repaired or otherwise worked on in reasonably dry conditions. Once this maintenance work has been completed the sluice gate 6 will be raised and when the water level in the pipeline returns to its normal level the skirt 4 will be deflated enabling the tubular member 2 to be withdrawn and the whole unit to be removed from the manhole on its support cable 3.

A double collar 9 divides the tubular member 2 into two parts which can be separated by removing securing bolts.

The section incoporating the expandable skirt 4 can then be replaced by one of a different size to suit a pipeline of a larger or smaller diameter. Furthermore, the extension section of the tubular member could be interconnected between the two flanges 9 so that the expandable sleeve 4 is projected forwardly of the support 1. This enables the device to be used in manholes where the normal crosssection of the pipeline is set back at the end of a portion of enlarged diameter.

Claims

1. A pipe closure device comprising a sluice gate on a support and a tubular member for insertion into the pipe and projecting from one side of the support and aligned with the sluice gate opening, the tubular member having an external flexible sealing skirt which will adjust to seal the gap between the pipe and the tubular member.

2. A closure device as claimed in Claim 1, including powered operating means for raising and lowering the sluice gate.

3. A closure device as claimed in Claim 1 or Claim 2, wherein the skirt tapers inwardly towards the free end of the tubular member.

4. A closure device as claimed in Claims 1 to 3, wherein the skirt is expandable by expansion means to seal the gap between the pipe and the tubular member.

5. A closure device as claimed in Claim 4, wherein the skirt is in the form of a tyre, with or without an inner tube.

6. A closure device as claimed in any one of Claims 1 to 5, wherein the tubular member is detachably mounted onto the support.

7. A closure device as claimed in any one of Claims 1 to 6, wherein the tubular member has an elongate extension section between the support and the skirt.

8. A closure device as claimed in Claim 7, wherein the extension section is removably mounted between flange members on the tubular member.

9. A pipe closure device substantially as herein described with reference to the accompanyingdrawings.