POLYVOLUME BELLOWS AND METHOD OF MANUFACTURING THE SAME Russian patent published in 2003 - IPC

FIELD: construction industry, in particular, construction and operation of various types of pipelines. SUBSTANCE: bellows have at least two corrugated enclosures inserted one into another. Enclosure corrugations have equal pitch and rest one upon another over axially aligned slots. Enclosures are welded to one another at their ends. Method involves creating excessive pressure in cavity defined between adjacent enclosures; installing separable mold outside pipe blank; pressurizing and supplying pressure of forming medium in mold and simultaneously applying axial force to pipeline blank; before pressurizing, inserting pipeline blank into single bellow; expanding single bellow to size defining volume of cavity between bellows; setting separable mold walls in single bellow slots; corrugating polyvolume bellows until corrugation pitch of predetermined size is set. EFFECT: enhanced reliability in operation and wider range of technical facilities. 3 cl, 7 dwg