Pressure testing of fixed-tube-sheet heat exchangers

For fixed-tube-sheet heat exchangers, when the test pressure in the tube side is higher than that in the shell side, the new version 151 does not specify that the test pressure for the shell side should be set to match that of the tube side. The advantage of this approach is that it allows for the inspection of both the shell and the tube ends; otherwise, when pressurizing the tube side, leaks at the tube ends might occur and would go unnoticed.

It’s not specified; it should be fine to not follow the shell along with the tube side.

When the experimental pressure in the tube side is higher than that in the shell side, 151 does not specify that the experimental pressure in the shell side should be set according to that in the tube side. Is this correct? ——Yes.

Of course, we can’t proceed based on the test pressure for the monitor; otherwise, if the thickness of the shell’s sidewall turns out to be insufficient, would we have to increase the shell thickness as well? Don’t you think that’s putting the cart before the horse?

This post was last edited by gn_1984 on 2016-2-24 09:53. The standard does not state that it is definitely correct. Because sometimes, when there is a large difference between the pressure in the tube side and that in the shell side, simply increasing the hydrostatic test pressure on the shell side requires that the strength of the shell side be verified to meet requirements, which also leads to waste of metal in the equipment. The standard does not specify this, which means that in situations where the pressure in the tube side is higher than that in the shell side, designers must determine appropriate inspection methods based on the requirements and circumstances. The following methods are commonly used to address this issue: 1. Increase the test pressure on the shell side to match that of the tube side; however, in such cases, the components on the shell side must be tested under this increased pressure to ensure their integrity. 2. Use a permeable medium for shell-side pressure testing. When the pressure in the tube side is much higher than that in the shell side, or when it is not possible to increase the pressure used for shell-side testing, a highly permeable medium such as ammonia or Freon can be employed for this purpose, in order to inspect the connections between the heat exchange tubes and the tube sheet. 3. Changing the design pressure of the tube sheet can also be an option; sometimes the tube sheet design can be modified to use a pressure difference approach in order to address the issue of testing situations where the pressure in the tube side is higher than that in the shell side.

I have encountered this before; the pressure in the tube side of the reactor is related to the pressure in the shell side. It is sufficient to carry out pressure testing using the method employed for reboilers

Our usual practice is to test the tube side and shell side at their respective test pressures; if the pressure in the tube side is higher than that in the shell side, an additional ammonia and helium leak test is conducted on the shell side.

Our usual practice is to test the shell and tube sides at their respective test pressures.

Our company’s standard practice is to test the shell and tube sides at their respective test pressures. There are very few failures.