METHOD OF MANUFACTURE OF PIPE WITH INNER PROTECTIVE COAT Russian patent published in 2002 - IPC

FIELD: construction engineering; erection and repair of various pipe lines used for transportation if chemically aggressive media. SUBSTANCE: proposed method consists in forming and securing cylindrical inserts made from corrosion-resistant metal inside ends of pipe. Inserts are made by multi- layer winding or fitting rings from thin-walled roll corrosion-resistant metal; first layer or first ring is connected with inner surfaces of pipe ends; subsequent layers or rings are interconnected by bonding, soldering and welding. Inner ends of inserts are stepped in form due to shift of layers relative each other; protective coat is applied to free ends of layers. Layers of inserts are interconnected by adhesive corrosion-resistant dielectric material or adhesive corrosion-resistance protector material; outer ends of inserts are fastened by rings made from corrosion-resistant metal. EFFECT: enhanced reliability of welded joints of pipe lines. 4 cl, 2 dwg