Latest type of 'U' blending machinery is used for precision cold bending of tubes. Specifically prepared jigs and fixtures are used to ensure three dirnensional accuracy for 'U' bend tubes. 'U' bendling is done for all kind of heat exchanger, condensor, economiser, boiler tubes in carbon steel alloy steel & stainless steel seamless as well as welded 'U' bending can be done for tubes up to a length of 100 feet. At HMT tubes can be 'U' bent upto R= 1 Dia.
Subsequently 'U' bend tubes are hydro tested, stress relieved, if specified, also mock- up pieces are for determining thickness reduction of the
bend portion. Dye penetrant testing on bend portion is done to detect cracks, meets the most critical requirement of the customer
Stress Relieving of Carbon Steel & Alloy Steel'U' Tube:

'U' portion + 30Omm on each leg length are annealed (Stress Relieved) in a batch type furnace in which temperature is closely controlled & recorded. Rate of cooling is also controlled, as per the heat treatment cycle given by the customer.
Heat Treatment of Stainiess Steel 'U' Tube

'U' Portion + 300mm on each leg length are heated at 1050 C temperature by transformer. The temperature is measured by an optical pyrometer.
Cooling is done immediately by blowing air to avoid carbide precipitation.