British Gas Plc

Anthony D Elgar

Brian T Sales

Adrian S Parkes

Robert Neal Bennett

Frame for sign

A method for blocking the bore of a pipe comprising moving an inflatable bag along the bore of the pipe from an access point in the pipe to a point where the bore is to be blocked, inflating the bag until it engages the internal wall of the pipe or main and causing the bag to maintain its inflated condition. Where an expandable foam is used.

Pipe blocking technique

A method is provided for replacing a length of a branch gas main 1 joined to a spine main 2 with a length of replacement main 7 having an outer diameter smaller than the inner diameter of the branch main. In the method access is gained to the bore of the branch main and one end of the replacement main 7 is fed along the branch main 1 via the access point and towards the spine main 2 until the branch main 1 has been replaced. During and after the feeding step gas is prevented from entering any clearance 20 between the mains 1 and 7 by means of a head 9 attached to the leading end of the main 7. After the feeding step a sealant 25 is injected into the branch main 1 to form a seal within the clearance 20.

Method of replacing branch mains

A method and apparatus for abandoning a branch main 1 joined to a fluid-carrying spine main 2 comprises gaining access to the bore of the branch main 1 at an access point and then permanently blocking the bore of the branch main 1 at a blockage point closer to the junction then to the access point.

Apparatus for the abandonment of a branch main

A method for abandoning a branch main 1 joined to a fluid-carrying spine main 2 comprises gaining access to the bore of the branch main 1 at an access point and then permanently blocking the bore of the branch main 1 at a blockage point closer to the junction then to the access point.

Growing community of inventors

Mitcham, United Kingdom

Anthony D Elgar