EP0068657A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method of mains insertion
Assignee: British Gas PLC
•
Filing: 1982-06-04
•
Granted: —
•
Expires: 2002-06-04
Abstract
Abstract In a method of replacing a section of an old cast iron main with a new main of plastics pipe material, the section (2) to be replaced is isolated from the adjacent live main (16) after a by-pass (5) is fitted between the section (2) and the main (16). One end of the pipe (52) is then pushed up the isolated section (2) until a desired length is located within the isolated section (2) and the other end of the pipe (52) is connected to the end (18) of the adjacent main (16). This enables the isolated section (2) to be kept alive solely by gas flow through the pipe (52) from the main (16) and the by- pass (5) can therefore be removed.
Inventors
- 👤 Douglas Charles Soper
- 👤 Brian Gould
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 15:26
CPC Classifications
F; F16; F16L; F16L55/00; F16L55/16; F16L55/1608; F16L55/18; Y; Y10; Y10T; Y10T137/00; Y10T137/0318; Y10T137/0402; Y10T137/0441
Claims Analysis
Total Claims: 67
Claim 1
Independent Claim
77 words
A method for maintaining live a section of a existing main isolated from the rest of the main until service lines connected to the isolated section are disconnected therefrom and reconnected to a replacement main of smaller diameter than the existing main, and located within the isolated section, the method comprising allowing fluid to flow between a live part of the rest of the existing main and the isolated section solely by way of the replacement main.
Claim 2
Independent Claim
77 words
A method for maintaining live a section of a existing main isolated from the rest of the main until service lines connected to the isolated section are disconnected therefrom and reconnected to a replacement main of smaller diameter than the existing main, and located within the isolated section, the method comprising allowing fluid to flow between a live part of the rest of the existing main and the isolated section solely by way of the replacement main.
Claim 3
Dependent Claim
19 words
A method as claimed in Claim 1 in which the replacement has an opening located in the isolated section.
Claim 4
Dependent Claim
30 words
A method as claimed in Claim 2 in which the opening is located beyond the service line most distant from the live part of the rest of the existing main.
Claim 5
Independent Claim
40 words
A method as claimed in any of the preceding claims in which the replacement main is connected to that part of the rest of the main adjoining that end of the isolated section into which the replacement main is inserted.
Claim 6
Independent Claim
96 words
A method for replacing a section of an existing main with a replacement main of smaller diameter than the existing main, the method comprising isolating the section of the existing main from the adjacent existing main after ensuring that the isolated section is supplied with fluid independently of its previous junction with the existing main, pushing one end of the replacement main into but not externally of the isolated section until a desired length of replacement main is located within the isolated section and connecting the other end of the replacement main to the existing main.
Claim 7
Independent Claim
96 words
A method for replacing a section of an existing main with a replacement main of smaller diameter than the existing main, the method comprising isolating the section of the existing main from the adjacent existing main after ensuring that the isolated section is supplied with fluid independently of its previous junction with the existing main, pushing one end of the replacement main into but not externally of the isolated section until a desired length of replacement main is located within the isolated section and connecting the other end of the replacement main to the existing main.
Claim 8
Dependent Claim
41 words
A method as claimed in Claim 5 in which fluid is allowed to enter the length before it is being pushed up the isolated section and to discharge from the length after the replacement main is connected to the existing main.
Claim 9
Dependent Claim
44 words
A method as claimed in Claim 6 in which the fluid is allowed to enter and flow out of the length for a period before the replacement main is pushed up the isolated seetior so as to purge the replacement main of any air.
Claim 10
Dependent Claim
33 words
A method as claimed in Claim 7 in which at the end of the period, the flow of fluid out of the replacement main is obstructed at some point outside the isolated section.
Claim 11
Dependent Claim
64 words
A method as claimed in Claim 8 in which before the replacement main in connected to the existing main, the flow of fluid along the replacement main is further temporarily obstructed at some point upstream of the obstruction but outside the isolated section, the other obstruction is removed the replacement main is connected to the adjacent existing main and the temporary obstruction is removed.
Claim 12
Independent Claim
23 words
A method as claimed in any of Claims 5 to 9 in which fluid enter and discharges from the end of the length.
Claim 13
Independent Claim
26 words
A method as claimed in any of Claims 5 to 10 in which fluid is allowed to enter the length before it enters the isolated section.
Claim 14
Independent Claim
65 words
A method as claimed in any of Claims 5 to 11 in which the replacement main is caused to enter an entry end of the isolated section by way of a temporary seal connected to the entry end of the isolated section, the temporary seal being subsequently removed therefrom and from the replacement main before the replacement main is connected to the adjacent existing main.
Claim 15
Dependent Claim
49 words
A method as claimed in Claim 12 in which before the temporary seal is removed, the space between the external wall of the length of replacement main and the internal wall of the isolated section is sealed at a point close to the entry end of the isolated section.
Claim 16
Dependent Claim
45 words
A method as claimed in Claim 13 in which after the temporary seal is removed the space between the external wall of the length of replacement main and the internal wall of the isolated section is sealed at the entry end of the isolated section.
Claim 17
Independent Claim
40 words
A method as claimed in any of Claims 10 to 14 in which the end of the length is located beyond that service line connected to the isolated section and most distant from the entry end of the isolated section.
Claim 18
Dependent Claim
43 words
A method as claimed in Claim 15 in which the end is sealed after all but those two service lines most distant from the entry end of the isolated section are disconnected from the isolated section and reconnected to the replacement main. -
Claim 19
Dependent Claim
158 words
A duct for connection to an end of an isolated section of an existing main so as to enable a smaller diameter replacement main to be inserted thereinto to replace the isolated section, the duct having a wall defining an internal axial bore for the passage therethrough of the replacement main and a resilient annular seal having an internal periphery for engaging with the external wall of the replacement main, the seal being located within the bore in such a way that the seal forms a barrier to fluid flow within the annular space between the external wall of the replacement main and the internal wall of the duct when the replacement main is engaged by the internal periphery of the seal, the duct having at least one aperture extending through its wall into the bore for the injection into the bore of a lubricant to lubricate the external wall of the replacement main before engaging the seal.
Claim 20
Dependent Claim
158 words
A duct for connection to an end of an isolated section of an existing main so as to enable a smaller diameter replacement main to be inserted thereinto to replace the isolated section, the duct having a wall defining an internal axial bore for the passage therethrough of the replacement main and a resilient annular seal having an internal periphery for engaging with the external wall of the replacement main, the seal being located within the bore in such a way that the seal forms a barrier to fluid flow within the annular space between the external wall of the replacement main and the internal wall of the duct when the replacement main is engaged by the internal periphery of the seal, the duct having at least one aperture extending through its wall into the bore for the injection into the bore of a lubricant to lubricate the external wall of the replacement main before engaging the seal.
Claim 21
Dependent Claim
60 words
A duct as claimed in Claim 17 in which another resilient annular seal is located within the bore of the duct and is so spaced axially from the other seal that the aperture communicates with the bore at a point located between the seals, the-other seal having an internal periphery for engaging with the external wall of the replacement main.
Claim 22
Dependent Claim
48 words
A duct as claimed in any of Claims 17 or 18 in which the duct includes a valve for location nearer to the entry end of the isolated section than the seal forming the barrier to fluid flow, the valve being operable to open and close the duct.
Claim 23
Dependent Claim
15 words
A duct as claimed in Claim 19 in which the valve comprises a movable gate.
Claim 24
Dependent Claim
34 words
. A duct as claimed in any of Claims 17 to 20 in which the duct includes two detachably screw fitted portions, one of which houses the seal forming the barrier to fluid flow.
Claim 25
Dependent Claim
32 words
A duct as claimed in Clain 21 in which the other portion forms a chamber between the seal and the valve for the insertion therein of the end of the replacement main.
Claim 26
Dependent Claim
20 words
A duct as claimed in Claim 21 or Claim 22 in which the seal is forcibly retained between the portions.
Claim 27
Dependent Claim
38 words
A duct as claimed in Claim 23 in which the seal is retained between a radial flange projecting inwardly from the internal wall of the portion housing the seal and the screw threaded end of the other portion.
Claim 28
Dependent Claim
102 words
A head for insertion into an isolated section of an existing main so as to enable fluid either to flow into or out of a replacement main which is to replace the isolated section, the head having one end for connection to the end of the replacement main which is to be inserted into the isolated section, an apertured nozzle communicating with a bore in the end of the head to permit fluid to flow into and out of the head and means for preventing the nozzle contacting the internal surface of the isolated section as the head moves therealong during insertion.
Claim 29
Dependent Claim
102 words
A head for insertion into an isolated section of an existing main so as to enable fluid either to flow into or out of a replacement main which is to replace the isolated section, the head having one end for connection to the end of the replacement main which is to be inserted into the isolated section, an apertured nozzle communicating with a bore in the end of the head to permit fluid to flow into and out of the head and means for preventing the nozzle contacting the internal surface of the isolated section as the head moves therealong during insertion.
Claim 30
Dependent Claim
40 words
A head a claimed in Claim 25 in which the means comprises bars extending axially of the nozzle and adapted to maintain the nozzle spaced apart from the internal - surface of the isolated section as the head moves therealong.
Claim 31
Dependent Claim
20 words
A head as claimed in Claim 25 or Claim 26 in which the nozzle comprises at least one perforated cylinder.
Claim 32
Dependent Claim
33 words
A head a claimed in Claim 27 in which the nozzle comprises three concentric perforated cylinders in which perforations in the middle cylinder are smaller than thos in the outer and inner cylinders.
Claim 33
Dependent Claim
22 words
A head as claimed in Claim 28 in which the perforations in the outer and inner cylinders are substantially the same size.
Claim 34
Dependent Claim
18 words
A head as claimed in Claim 28 or Claim 29 in which the middle cylinder is a gauze.
Claim 35
Dependent Claim
30 words
A head as claimed in any of Claims 25 to 29 in which the head has a curved nose at the other end to enable the head to traverse obstructions.
Claim 36
Dependent Claim
94 words
An assembly 'for insertion into an isolated section of an existing main, the assembly comprising a replacement main of smaller diameter than the isolated section for replacement of the the isolated section and a head attached to the end of the replacement main, the head having an apertured nozzle communicating with a bore in the end of the head to permit fluid to flow into and out the head, the nozzle having a number of apertures whose total area is at least equal to the area of the internal bore of the replacement main.
Claim 37
Dependent Claim
94 words
An assembly 'for insertion into an isolated section of an existing main, the assembly comprising a replacement main of smaller diameter than the isolated section for replacement of the the isolated section and a head attached to the end of the replacement main, the head having an apertured nozzle communicating with a bore in the end of the head to permit fluid to flow into and out the head, the nozzle having a number of apertures whose total area is at least equal to the area of the internal bore of the replacement main.
Claim 38
Dependent Claim
29 words
An assembly as claimed in Claim 32 in which the total area of the apertures is at least three times that of the internal bore of the replacement main.
Claim 39
Dependent Claim
28 words
34 An assembly as claimed in Claim 33 in which the total area of the apertures is four times that of the internal bore of the replacement main.
Claim 40
Dependent Claim
36 words
An assembly as claimed in any of Claims 32 to 34 in which the head includes means for preventing the nozzle contacting the internal surface of the isolated section as the head moves therealong during insertion.
Claim 41
Dependent Claim
37 words
An assembly as claimed in Claim 35 in which the means comprises bars extending axially of the nozzle to maintain the nozzle spaced apart from the internal surface of the isolated section as the head moves therealong.
Claim 42
Dependent Claim
17 words
An assembly as claimed in Claim 36 in which the nozzle comprises at least one perforated cylinder.
Claim 43
Dependent Claim
34 words
An assembly as claimed in Claim 37 in which the nozzle comprises three concentric perforated cylinders in which the perforations in the middle cylinder are smaller than those in the outer and inner cylinders.
Claim 44
Dependent Claim
22 words
An assembly as claimed in Claim 38 in which the perforations in the outer and inner cylinders are substantially the same size.
Claim 45
Dependent Claim
18 words
An assembly as claimed in Claim 38 or Claim 39 in which the middle cylinder is a gauze.
Claim 46
Dependent Claim
30 words
An assembly as claimed in any of Claims 32 to 40 in which the head has a curved nose at the other end to enable the head to traverse obstructions.
Claim 47
Dependent Claim
21 words
An assembly as claimed in any of Claims 32 to 41 claims in which the replacement main is a flexible pipe.
Claim 48
Dependent Claim
15 words
43 An assembly as claimed in Claim 42 in which the pipe is of plastics.
Claim 49
Independent Claim
116 words
A device for connecting a flexible pipe to the inlet end of a purge valve, the device comprising a cylindrical body having a central axial bore for the passage of fluid from the pipe to the valve, a first portion adapted to be fitted into the end of the pipe and a second portion having means for connecting its bore to the inlet end of the purge valve, the first portion having a resiliently deformable section inwardly of a rigid end section and the second portion being rigid and means for urging the portions together to cause the resiliently deformable section to expand radially outwardly to form a seal with the internal wall of the pipe.
Claim 50
Independent Claim
116 words
A device for connecting a flexible pipe to the inlet end of a purge valve, the device comprising a cylindrical body having a central axial bore for the passage of fluid from the pipe to the valve, a first portion adapted to be fitted into the end of the pipe and a second portion having means for connecting its bore to the inlet end of the purge valve, the first portion having a resiliently deformable section inwardly of a rigid end section and the second portion being rigid and means for urging the portions together to cause the resiliently deformable section to expand radially outwardly to form a seal with the internal wall of the pipe.
Claim 51
Dependent Claim
28 words
A device as claimed in Claim 44 in which the deformable section of the first portion comprises two resiliently deformable annular members separated by a rigid annular member.
Claim 52
Dependent Claim
64 words
A device as claimed in Claim 44 or Claim 45 in which the means for urging the portions together comprises two bolts extending axially through the body by way of two axially extending bores therein and located diametrically opposed on opposite sides of the central axial bore, the bolts being at least partly threaded inwardly from their ends for connection to correspondingly threaded nuts.
Claim 53
Independent Claim
40 words
A device as claimed in any of Claims 44 to 46 in which the second portion has its bore at least partly threaded inwardly from one end for connection to a corresponding externally threaded portion on the purge valve inlet.
Claim 54
Independent Claim
24 words
A device as claimed in any of Claims 44 to 47 in which the second portion has a greater diameter than the first portion.
Claim 55
Dependent Claim
25 words
A device as claimed in Claim 48 in which the first portion is joined to the second portion by way of a rigid annular section.
Claim 56
Independent Claim
28 words
A method for maintaining live a section of an existing main isolated from the rest of the main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 57
Independent Claim
28 words
A method for maintaining live a section of an existing main isolated from the rest of the main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 58
Independent Claim
19 words
A method for replacing a section of an existing.main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 59
Independent Claim
19 words
A method for replacing a section of an existing.main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 60
Dependent Claim
25 words
A duct for connection to an end of an isolated section of an existing main substantially as hereinbefore decribed with reference to the accompanying drawings.
Claim 61
Dependent Claim
25 words
A duct for connection to an end of an isolated section of an existing main substantially as hereinbefore decribed with reference to the accompanying drawings.
Claim 62
Dependent Claim
22 words
A head for insertion into an isolated section of an existing main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 63
Dependent Claim
22 words
A head for insertion into an isolated section of an existing main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 64
Dependent Claim
22 words
An asembly for insertion into an isolated section of an existing main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 65
Dependent Claim
22 words
An asembly for insertion into an isolated section of an existing main substantially as hereinbefore described with reference to the accompanying drawings.
Claim 66
Dependent Claim
25 words
.A device for connecting a flexible pipe to the inlet end of a purge valve substantially as hereinbefore described with reference to the accompanying drawings.
Claim 67
Dependent Claim
25 words
.A device for connecting a flexible pipe to the inlet end of a purge valve substantially as hereinbefore described with reference to the accompanying drawings.
References Cited (Backward Citations)
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