Heat Exchanger Drying

[MrBTU]

Hello,
Last year DK44 created a thread regarding drying of heat exchangers after fabrication and hydrotest (thread794-436465).
I have this requirement on a job I am currently quoting. I would like to know the solution that was used and any suggestions.
My requirement is 10 ppm of water. My heat exchanger is 30 ft long, 30" diameter, all 304 SS, qty 519, 3/4" x 16BWG tubes, single pass.

 

[georgeverghese]

10ppm water in air has a partial pressure of 1Pa (1e-3kPa). So, if you can operate the vac pump down to say 80% of this pressure and maintain this pressure for say 4-6hours, all the liquid water in the HX would have evaporated off. Fill and purge the HX with dry N2 after this and blank / plug off all ports.