Gas pipe safety seal - comprises plastic ring screwed into union with half-shells spring-loaded shut

摘要

The safety seal is for use when connecting up a gas meter to the main, after the branch union has been welded to the latter. It is of plastics, with an externally-threaded ring screwed into the union. On the underside of the ring are two half-shells, joined to it by an 8mm elastic union which holds them shut. On removal of the tool used to cut through the wall of the main pipe, the shells shut automatically, preventing gas escape. To reach the half-shells to unlock them, they have cut-outs for a seventy millimetre pipe, which has a fourty-five degree start cut in it.