Bending tool for stainless-steel tubes using cryogenic technique

The design of a special bending tool which is used in the formation of $90^o$ bends for the tube-in-tube helium flow passages of a remote delivery tube is described. The concentric thin walled stainless-steel tube assembly is filled with water and cryofrozen before they are clamped into the bending tool. The tubes are bent by pressing the tube using the bending lever over the guiding wheel. The split bush and split cone clamping arrangement ensures that there is no movement of the tubes during the bending operation. This procedure has yielded kink-free bends with good circularity