Regarding the selection of 15CrMo heat exchange tubes
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There is a heat exchanger currently, with a design pressure of 13 MPa for the tube side. The material used for the heat exchange tubes is 15CrMo. The question is that according to six relevant standards, when the design pressure is 10 MPa or higher, tubes specified in standard 6479 should be used; however, standard 150 does not mention 15CrMo tubes from standard 6479. Which standard should then be applied for selecting the heat exchange tubes? Waiting for an expert to provide an answer! ! ! Thank you! ! !
This post was last edited by gn_1984 on 2019-8-12 at 10:01. 15CrMo heat exchange tubes can be used in accordance with GB9948; however, it is necessary to conduct a hydrostatic test on each tube individually during procurement, with the hydrostatic test pressure being set at the higher of the pressures required for testing the shell side and the tube side. Generally, opening reinforcement is used; GB6479 is applied when the pressure in pipes such as pipelines exceeds 10 MPa. There should be no restrictions on heat exchange tubes, right?
Also, generally to avoid cracks and leaks resulting from heat treatment during the welding of CR-M0 steel, stainless steel is used for the heat exchange tubes, while a cladding structure is employed for the tube sheets. This avoids both welding of dissimilar steels and heat treatment. Compared to CR-M0 steel, the joint is less prone to cracking and leakage. Safe and reliable.
Well, after thinking about it, it’s safer to use 9948. . . There’s nothing we can do; the customer insists on using this. For heat treatment, only local treatment of the pipe ends is possible.