METHOD OF CONNECTION OF STEEL PIPES PROVIDED WITH INTERNAL ANTI-CORROSION COATS Russian patent published in 2005 - IPC

FIELD: pipe line transport; erection of pipe lines provided with internal anti-corrosion coats.

SUBSTANCE: proposed method includes calibration of ends of pipes over internal diameter to maximum size; then, anti-corrosive coat is applied to internal surfaces of pipes and bushes made from anti-corrosive steel are mounted inside ends of pipe overlapping part of coat; said bushes have sealing layers on their external surfaces. Bushes are secured by flaring with the aid of mandrel till contact with internal surfaces of pipes at negative allowance; pipes are connected by butt welding according to procedure of welding double-layer pipes with internal layer made from corrosion-resistant steel. Sealing layer may be located in circular bore which is open at internal end face of bush or in immediate proximity; it may be applied in form of continuous coat over entire external surface of bush but for zone of thermal effect on outer end arising in the course of welding.

EFFECT: facilitated procedure; low cost of procedure.

5 cl, 4 dwg