Leak testing of air cool and shell and tube heat exchangers

[lutherk1]

Are there any guidelines for leak testing of heat exchangers? This is not for code strength repairs, but more for product contamination. I believe that they should be tested at some factor of operating pressure, but less than MAWP or design pressure. We have found that 1.1 or 1.5 time design pressure is excessive for the intended purpose. In addition, are air-cooled exchangers treated differently? Could the test be performed with nitrogen instead of water?

 

[weeeds]

There are many types of tests that are used in industrial applications. The standard water pressure test is suitable for most equipment but will not detect very small defects that can result in leaks over time. Depending on the acceptable leak rate (all joints and materials leak) a gas test may be acceptable. With nitrogen you will still only find reasonably large leaks as you will have to spray soapy water to see an indication. For more sensitive applications such as chemical processing, food, pharmaceuitical, lethal, expensive materials etc. you may want to use Helium Leak Detection. There are a number of service providers who do this in the field. If you let me know what part of the world you are in I may be able to give you some contacts.