MULTI-PASSAGE PIPE LINE FOR TRANSPORTATION OF LIQUID AND/OR GAS UNDER HIGH PRESSURE Russian patent published in 1999 - IPC

FIELD: pipe line transport; oil and gas lines; chemical and wood-pulp and paper industries; metallurgy. SUBSTANCE: multi-passage pipe line includes outer pipe and at least one inner pipe mounted inside outer pipe on sliding supports at spaced relation. Clearance between outer and inner pipes forms outer pipe line passage and inner pipe forms inner pipe line passage. Pressure of product transported via inner passage exceeds pressure of product transported via outer passage. Intermediate pipe line may be laid between inner and outer pipe lines. Pipe lines are fixed relative to each other by means of plate springs. EFFECT: enhanced reliability of pipe line. 4 cl, 6 dwg