Shell and Tube Heat Exchanger Replace points to note
shell and tube heat exchanger also known as tube heat exchanger. Is a wall-type heat exchanger which is a wall-side heat exchanger which is closed to the wall of the tube bundle in the casing as a heat transfer surface. This kind of heat exchanger structure is simple, reliable operation, can use a variety of structural materials (mainly metal materials), can be used in high temperature, high pressure, is currently the most widely used type.Shell and Tube Heat Exchanger Replacement Note:
1, the pipe surface should be no cracks, folding, heavy skin and other defects.
2, the pipe to be spliced, the same heat transfer tube, up to a quasi-welding (U-shaped tube can have two welding). The shortest pipe length shall not be less than 300mm, and the U-shaped pipe bend pipe section at least 50mm, long straight pipe section shall not have splicing weld, the wrong amount should not exceed the wall thickness of 15%, and not more than 0.5mm.
3, pipe and tube plate should be used to check the hardness of the tube expansion, the general requirements of the hardness of the tube than the tube plate hardness 30HB. When the hardness of the pipe is higher than or close to the hardness of the tube plate, the pipe shall be annealed at both ends, and the annealing length shall be 80 ~ 100mm longer than that of the tube plate.
4, both ends of the tube and tube plate hole should be clean, no grease and other dirt, and shall not have through the vertical or spiral scoring and other effects of expansion close to the type of defects.
5, the tube ends should be out of the tube plate, the length of 4 ± 1mm.
6, tube and tube plate expansion should adopt hydraulic expansion. Each inflatable expansion may not be more than twice.
7, pipe and tube plate using welding, the pipe surface should be flat, no burrs, bumps, cracks, sandwich, etc., and the welding may not have slag, iron oxide, grease and other effects of welding quality debris.