Inspection and pressure testing plan for fixed-tube-sheet heat exchangers
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How to carry out inspection and pressure testing for a fixed-tube-sheet heat exchanger? The design pressure for the shell side is 0.55 MPa, with an operating pressure of 0.5 MPa; the fluid used is circulating water. The design pressure for the tube side is 1.22 MPa, with an operating pressure of 1.15 MPa; the fluid used here is nitrogen oxide gas. The pressure in the tube side is higher than that in the shell side; I’m not sure how to carry out pressure testing
The shell-side test pressure is determined based on the tube-side test pressure.
First, it is necessary to calculate the value for the hydraulic test of the tubes; this value is then used to determine whether the shell can withstand such pressure. If it can, then it’s fine; otherwise, the thickness of the shell must be increased, or methods such as ammonia leakage testing or helium leak testing should be employed to assess the quality of the welds between the tubes and the tube sheet.
3# is absolutely correct; do not use the pressure from the tube side blindly for the shell side – it is necessary to carry out calculations first. If that doesn’t work, then consider ammonia leakage in the shell side.
Just follow the requirements in the as-built drawings.
Are there any specific plans, or are there books that provide detailed explanations?
Increase the test pressure of the shell-side water or conduct an ammonia leakage check; if increasing the pressure, perform a strength calculation
If the test pressure for the tube side is high, the test pressure for the shell side should also be increased to match that of the tube side; otherwise, each side should be tested at its respective pressure, with an additional leak test conducted on the shell side to check the tightness of the welds at the tube ends