METHOD TO MANUFACTURE THIN WALL PIPES WITH EXTERNAL HELICAL FINS AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2014 - IPC B21C37/20 

FIELD: machine building.

SUBSTANCE: method involves shaping of a pipe with longitudinal fins and its twisting on a mandrel. Before and after shaping of the longitudinal fins and after twisting, the pipes are subject to vacuum heat treatment under the temperature in the recrystallisation range with the pipes being set vertically and distanced from each other in the furnace body. Torque is transferred via one pipe end fixed inside on the mandrel while the other pipe end is fixed outside in a jaw so that to form a gap between the pipe and the mandrel along the whole length of the twisted section with the gap value not exceeding the straightness tolerance, and so that to be able of rotating the mandrel in respect to the pipe. The device comprises relevant units.

EFFECT: simplified process of thin wall spiral pipe manufacturing without the usage of local heating along with high quality of a ready pipe.

9 cl, 1 dwg