METHOD OF CONNECTION OF TWO-LAYER METAL PIPES Russian patent published in 1997 - IPC

FIELD: oil, gas and chemical industries. SUBSTANCE: a layer of sealant is applied to ends of inner aluminium pipes; then bush made refractory material is fitted immovably; bush has internal taper thread and stops in its center; end of aluminium pipe is brought to bush and force is applied along axis of pipe to screw it to stop fitted in bush. Then aluminium pipe (with bush screwed on it) is inserted in metal pipe to half length of bush and is screwed into the bush, after which second metal outer pipe is fitted on connected aluminium pipes and they are welded together. EFFECT: enhanced reliability. 1 dwg