METHOD OF SLEEVE JOINING OF PIPES WITH INNER COATING Russian patent published in 2003 - IPC

FIELD: oil producing, chemical and other industries and sanitation facilities. SUBSTANCE: method of sleeve joining of pipes with inner coating includes forming of pipe end into nipple and use of connecting member in form of sleeve with bell-mouth at ends and press-fitting nipple into sleeve after preliminary application of anticorrosive coating and sealing compound onto inner surface. Prior to press-fitting the nipple, its end is bent to cone, conicity of bending not exceeding 10^o, labyrinth grooves are made on ends of sleeve bell-mouth and ring with labyrinth ring grooves on end faces for bent end of nipple is interference fitted in middle part of sleeve, and sealing hardening compound in form of circular beads is applied to end sections of nipple and sleeve. EFFECT: provision of reliable and quality sealing of joint, improved reliability, simplified joining process. 3 cl, 4 dwg