METHOD OF CONNECTION OF PIPES, FITTING AND PIPE CONNECTING MEMBERS Russian patent published in 1999 - IPC

FIELD: connection of members of lined pipes and pipe line fittings. SUBSTANCE: each steel member of pipe connected with steel tubular fittings by circumferential seam and each pipe is lined by drawing polyethylene insert via pull-through ring, pipe and fitting. Stainless steel ring is inserted in each fitting for compressing the insert and forcing it into grooves in inner surface of fitting. Grooves are separated by prongs. Grooves are made by mechanical method in corrosion-resistant cladding applied on inner part of each fitting. Each fitting may be wholly made from corrosion-resistant steel made by duplex process. Ends of inserts are cut near ends of fittings and circular layer made from material of insert is introduced into clearance. Circular layer has outer groove receiving the body made from heat-insulating material. Ends of fittings are clamped together and are connected by circumferential seam. EFFECT: enhanced reliability of joint. 8 cl, 8 dwg