Issues regarding the test pressure of floating-head heat exchangers
Thread Content
For a certain floating-head heat exchanger, the operating pressure in the shell side is higher than that in the tube side; the test pressure for the shell side is 3 MPa, while the test pressure for the tube side is 2.5 MPa. So, the pressure testing is carried out three times: the first time, the fitting is installed and the test pressure is 3 MPa; the second time, the pipe box and floating head are installed, with a test pressure of 2.5 MPa; the third time, the outer cover is installed, again at a test pressure of 3 MPa. So during operation, the pressure of the shell-side fluid in contact with the small floating head is higher than that on the tube side; yet pressure testing is carried out based on the tube side standards. How can leakage be prevented?
Generally, the tube side pressure is higher; increasing the shell side pressure may result in significant cost increases. The cost increase resulting from raising the pressure in the tube side won’t be very significant; moreover, the pressure difference between the tube side and the shell side of this container is not large. After doing some calculations, it’s better to set the pressure in the tube side equal to that in the shell side.
If the test pressure for the tube sheet is 1.0, how is the floating head seal tested?
Key points: The first test is carried out on the shell side using the tooling, to check whether there are leaks in the test tubes; the second test checks the sealing performance of the floating head; the third test checks the sealing performance of the gasket on the large end. Following this approach, all heat exchangers must undergo the same shell-and-tube pressure test. . Understanding implies errors
Since the floating head seal is in contact with both the tube side and the shell side, how should the test pressure be determined? Should I choose the tube side or the shell side? Thank you.
Take a look at GB151 for static equipment, or SHS01009
When working with equipment, follow the specifications – that way you can’t go wrong, man
Take a look at the operating pressure on the shell side
Increase the test pressure for the tube side to 3.0 times the test pressure of the shell side. Check whether the stress values of all stressed components during the tube side pressure test meet the standard requirements.
If you’re not confident, have the designer do the calculations – just increase the pressure in the tube side to make it equal to the pressure in the shell side!