Repair of cracked tube of heat exchanger - using bush made from memory metal, expanded by heating via electric element

摘要

A tubular heat exchanger has the tubes (2) supported at their ends in a header plate (1). In the event of a crack (3) occurring in a tube, the tube is repaired in the following way. A sleeve (4) is inserted in the tube (2) to cover the area of the crack (3). A bush (5) made of 'memory' metal is then inserted inside the sleeve (4) with the aid of a tool (6). The bush is then heated by an electric element (7) so that it expands radially and expands the sleeve (4) to form a pressure fit in the tube. The electric element is then removed to allow the bush to cool. When the bush has cooled it is removed leaving the radially expanded sleeve in place. USE - Repair of heat exchanger tubes.