1 reply to this topic

[ehsan1982]

Hi All,

 

I have a question about nitrogen tightness test adn leak detection method,we have a project (process plant) to be tightness tested using nitrogen in different sub-system to pressure like 65,67,42,27 39,... barg,as far as I know soap bubble test is usally done to pressure 7 or 10 bar and beyound this pressure ,usually pressure drop method is used,my question is that :is it necessaary to do bubble test for nitrogent high pressure test or just monitoring pressure is enough and what is a allowable leak rate?

 

Regards,

Ehsan

[Sharma Varun]

Well Ehsan, soap test helps you in identifying leak location, i.e. exactly which flange needs to be tighten in case you observe a pressure drop. Regarding pressure drop i cannot comment  as I have never witnessed that for such high pressures. But remember that pressure does vary during day & night time based on exposed (to sun) segment of pipeline & ambient temperature.

 

regards,

Varun