The Large VGC Inspection Crawler from RBR50 company ULC Robotics was successfully used to inspect several large diameter cast iron gas mains operated by Scotia Gas Networks (SGN) in the suburbs of London and another city south of London.
The real-time video provided by the crawler allowed SGN to assess their mains, looking for pipeline features and debris that may hinder future projects at the selected locations.
Inspections with the Large VGC, as well as other cameras and crawlers from ULC, are capable of launching into and operating in live gas mains, so gas utilities such as SGN do not need to disrupt service to customers. In urban areas such as London, shutting down gas service in one main could lead to the costly and resource-heavy burden of relighting gas appliances in customers? homes or putting all residents on bottle service.
SGN delivers natural gas to 5.8 million customers in the United Kingdom. Their service territory covers all of Scotland and parts of England, including a section of London.
The Large VGC Crawler was built to inspect live 18?-48? gas mains without allowing methane to escape. The tethered crawler enters the gas main using a launch tube that mounts vertically onto a valve in a minimally sized pit and only requires a 4? tap hole in the main. Once inside the main, the Large VGC is capable of traveling 750? in either direction of the entry point for a total inspection distance of 1,500?.