APPARATUS FOR ELECTROHYDRAULIC EXPANSION OF TUBES Russian patent published in 2002 - IPC

FIELD: plastic metal working, possibly electric pulse expansion of tubes in tube plates of heat exchangers, sizing tubular blanks and vessels. SUBSTANCE: apparatus includes rod type high-voltage electrode with rigid insulation coating of high-pressure polyethylene and ground electrode in the form at least of one elastic metallic wire. Lower end at least of one elastic metallic wire is bent inside by 90 degrees; its upper end is secured to metallic mandrel. One end of expanded tube passed through tube plate is introduced to metallic mandrel. Elastic insert of insulation material is placed over bent end of wires of ground electrode. Upper portion of elastic insert is arranged over lower end surface of tube plate. It provides possibility for reduced expansion of tubes at boundary of inner surface of tube plate. EFFECT: lowered energy consumption for tube expansion. 1 dwg, 1 tbl