April 20, 2015

Due to potential leakage, it was necessary to replace two 3” steel gas service risers in a block of some 35 flats at the point where they entered the building. To avoid disrupting residents’ gas supply, with the subsequent need to test, purge and relight each dwelling, it was decided to carry out the operation live using Live Riser Transfer. This technique allows a gas riser to be partly...

This medium pressure gas main had previously been blanked off but the valve, acting as an end cap, was leaking. The customer, Manx Gas, decided that using the FOAMBAG™ technique to seal off the pipe was a costeffective alternative to conventional flow stopping methods. The project was carried out by our Special Contract Service team.

Niagara Mohawk, a National Grid company, recently undertook a gas mains insertion project in West Albany, upstate New York, which was carried out ‘live’ using a special technique pioneered in the United Kingdom. ‘Live’ mains insertion allows customers to remain on gas throughout the insertion process. The final stage of transferring the old services to the new PE main can then be...

The 6” low pressure main in the High Street of Paulton, near Bristol, was being replaced with a new PE pipe but one section needed to be kept live as it was feeding three homes. The National Grid Transco team used a FOAMBAG™ kit to flow stop the section to be abandoned before cutting out and tying the new PE to the live section. One-way traffic was maintained in the narrow, busy street....

Guernsey Gas has carried out the first live insertion of a gas main on the island for two decades. The project involved renewing 126 metre of cast iron main in Le Pollet in the centre of St. Peter-Port. A technician from Steve Vick International Ltd, the company which supplies equipment for the technique, was on site to offer help and advice. Only one excavation was required for the insertion,...

Live Gas Mains Insertion is a routine operation for Wales & West Utilities. In this project, they used Steve Vick International’s newly improved 125 pneumatic pushing machine with a 5” ram. The operation involved inserting 125mm PE into a 6” main in Wells, Somerset. WWU said that they found the pushing machine as powerful as a hydraulic machine and pushed the 94 metres of pipe in...

A Special Contracts Team from Steve Vick International recently carried out a flow stopping project for Manx Gas on two 22” gas mains in Douglas, Isle of Man. Located on South Quay, close to a gas holder, the 200 metre sections of two-way fed main were being abandoned so that governors could be installed in order to connect into a medium pressure system. Two x two-way flow stop operations,...

Our Special Contract Service team was in Stockholm at the end of April 2005 to flow stop a 24” low pressure gas main in the very heart of the city, outside the government buildings. A two kilometre section of the main, which was cast iron at one end and steel at the other, was to be abandoned. The team installed two double-skin FOAMBAGS™ at each end of the section. Once the expanding foam...

  Over 2000 metres of large diameter gas mains have been renewed using the new Steve Vick Pipe Handler in Attercliffe Road, a busy two way street in Sheffield. During the development stages with National Grid, they used the Live Mains Insertion technique to insert the pipe, ensuring customers and business owners experience minimal disruption during the operation. The Pipe Handler...

Replacing large diameter cast iron gas mains in city centres always poses enormous challenges for utility companies. Maintaining supply to businesses and homes, limiting the number and extent of excavations and keeping traffic and pedestrian disruption to a minimum are top of the list. One hundred and twenty five metres is not a particularly long project for live gas mains insertion, but when...

Morrison Utility Services, who hold the joint Western Gas Alliance contract alongside Amec, were recently contracted by Wales & West Utilities to carry out 3.6 kilometres of gas mains renewal in Cheltenham. The company decided to use the Live Mains Insertion (LMI) method of replacing the cast iron mains by inserting new PE pipe whilst the gas still flowed, thus minimising disruption and...

The technique was introduced into the UK in the 1980s by British Gas and has been pioneered and enhanced over three decades by Steve Vick International. Essentially, the major advantage of keeping the old cast iron main live whilst inserting it with a new PE pipe, is that customers are off gas for much shorter periods and, being a trenchless technology, it results in far less disruption to road...