Fixed Tube Sheet Exchangers; Identifying the Leak & Hydrotesting

[frcreek]

Hi All,

My question is on the FIXED TUBE SHEET Exchangers (tube sheet is welded to the shell), particularly, identifying a leak and hydrotesting;

The normal way is to water test shell side and look for the leaky tube on the tube side of the exchanger. Then, plug it or replace it.

But when the Shell side design pressure is lower than Tube side design pressure, how a leak can be identified, fixed and hydrotested? the shell side test pressure will always be low, not enough to show any leak!

Appreciate your advices,

Note: I had this posted in other forum but thought it better be posted here as well as it's related to Exchangers.

Thanks,

 

[MrBTU]

In the experience of my shop, the leak will show up in the tube even though the shell side is tested at a lower pressure. Are you saying that you tried this and no leak showed up?
In that case you could use a more sensitive test fluid, like hydrogen, and sniff the tubes, to see which one is leaking.

 

[CH5OH]

charge the tube with air pressure (plug one side, other side manometer, monitor pressure drop