MANDREL FOR LIQUID PRESSURE PIPE EXPANSION

摘要

A mandrel (1) for hydraulically expanding tubes (3) into engagement with a tubesheet (5), wherein the body (7) of the mandrel is flexible and preferably has an electrically isolating impermeable layer (12) and an eddy current coil (33) adjacent the leading end thereof, the tube (3) into which the mandrel (1) is placed and the body (7) of the mandrel (1) serving as leads for operating the eddy current coil (33) in order to determine when the leading end of the mandrel (1) is adjacent the inner edge of the tubesheet (5). With such a mandrel, also remote and obstructed tube can be reached and the mandrel can be properly positioned therein.