METHOD AND APPARATUS FOR MANUFACTURING WATERTIGHT, CORRUGATED METAL PIPES FROM A STRIP OF METAL SHEET, AND WATERTIGHT, CORRUGATED METAL PIPE MANUFACTURED BY SUCH METHOD Russian patent published in 2016 - IPC B21D37/12 F16L11/15 

FIELD: metallurgy; technological processes.

SUBSTANCE: present invention relates to a scope of metal forming, particularly, to method for manufacturing watertight, corrugated metal pipes. Longitudinal corrugations are formed on a strip of metal sheet by successive passages between counterposed corrugating barrels having alternated, circumferential ridges on their outer surfaces The opposite, longitudinal lips of the strip are bent in opposite directions. Then the strip of metal sheet is coiled into a helical shape, whereby the opposite, longitudinal lips overlap laterally. Before the opposite, longitudinal lips are crimped together between counterposed crimping rollers, a rubber gasket is fitted to one of the opposite longitudinal lips. Gasket has a bent profile capable of embracing the longitudinal lip at least partially. Whereby the material of the gasket, by effect of the crimping pressure, is reduced in thickness and deformed plastically at least in certain areas of the longitudinal lips which are biased against each other by the crimping action.

EFFECT: use of a rubber gasket with bent profile results in increased watertightness of the pipe.

10 cl, 11 dwg