摘要 |
1,157,456. Pipe joints. L. BAGNULO. 30 June, 1967 [6 July, 1966], No. 30227/67. Heading F2G. A prefabricated, electrically-insulated joint adapted to be inserted between the ends of metal piping 11 and 12 comprises a first tubular member 1 having a bell socket at one end, a second tubular member 4 having a flanged end 5 received in said socket, an electrically-insulating sealing ring 3 compressed between the flanged end and base of said socket, an externally-tapered locking ring 6 of electrically insulating material of high compressive strength having at least one slit clamped between the socket wall and second tubular member by conical deformation of the socket wall, a polymerizable resin filling the remaining spaces between the socket and second member, and a lining 8 of the same resin extending along each internal wall of the first and second members to prevent arcing therebetween. The joint is formed by inserting a resin-soaked gasket ring into the socket, inserting the flanged end of the second member into the socket, filling a major portion of the remaining space with the resin, positioning the insulating locking ring in the socket, axially compressing the gasket between the socket base and flange by exerting a force on the locking ring or second tubular member, and conically deforming the socket whilst compressing the sealing ring. The inner lining 8 is then applied to the internal walls. The outer surface of the second tubular member and the inner surface of the socket may be knurled or deeply sand-blasted to aid cohesion. The locking ring may be of Bakelite (Registered Trade Mark) or resin-impregnated fibreglass. |