Overlapped heat exchanger pressing
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The shell side is connected, while the tube side is not – how should pressure testing be carried out on the shell side? See the figure for parameters
GB/T151 8.13.8 specifies that pressure testing also needs to be carried out in the overlapping condition; at present, it is not clear how to perform pressure testing in this overlapping state
GB/T151 8.13.8 specifies that pressure testing also needs to be carried out in the overlapping condition; at present, it is not clear how to perform pressure testing in this overlapping state
Option 1: My own idea – connect the shell sides together and apply a pressure of 0.975 MPa (which, according to calculations, should be sufficient); however, the verification shows that this pressure is too high for the heat exchanger below. Option 2: According to the verification recommendations, apply pressures of 0.975 MPa/0.85 MPa to each shell side separately, and then apply a combined pressure of 0.125 MPa
First conduct pressure tests separately, then assemble them and conduct a pressure test together; it’s just a bit more complicated.
Use a precision pressure gauge as required by the design; if you’re not sure, it’s also okay to apply pressure separately first and then assemble them together to apply pressure. If the tube side and shell side of some heat exchangers are not properly welded or sealed, it is very difficult to apply pressure to them. It needs to be disassembled and reassembled many times.
Proceed in accordance with the requirements on page 109 of 151: after separate pressure testing of the tube side and shell side and confirmation that these tests are successful, carry out overlapping assembly; for the shell side, use a pressure of 0.125
Yes, for the above two heat exchangers, pressure testing is carried out on their shell sides and tube sides respectively; once they pass the testing, the two heat exchangers are assembled together and subjected to a combined pressure test at 0.13 MPa.
Fight separately; why fight together? The heat exchanger below is just a basic component. Next, consider the purpose of water pressure: if all the components that are subject to pressure have been checked, what’s the point? GB151 applies to Unicom’s heat exchangers.