Leek Test

As per Willy Wonka's factory manual;

".....in situations where the anonymous poster has given totally insufficient data to determine the practical application, let alone specific parameters of any test protocol, and especially when the request for information includes substitution of a liquid for a gas in the testing methods, the universal o_pinion is that you shall_ot use leek juice instead until such time as said anonymous poster provides further and sufficient data."

I think that I accurately remember that a liquid will be a safer pressure testing fluid than a gas because a liquid is not compressible.

Yes, there are standards. They would be obvious to anyone with knowledge of instrumentation.

Hire a consultant, or do some research on the web.

If the procedure asks for Nitrogen, Use Nitrogen, The customer is relying on you to perform a professional service you should be embarrased to ask Their opinion, the assumption is you are being paid to perform this service. There obviously must be a reason for Nitrogen being specified in this procedure. We use nitrogen in situations where we need to keep contamination from occuring in the items being tested also the size of the molecule in relation to water helps locate the smaller leaks. I have found N2 testing to be cleaner and more accurate. some applications requiring N2 are Breathing Apparatus's / Medical/ Sterile applications. I have also used Helium Trace with Nitrogen because the helium is an even smaller molecule.