Pressure Test Air vs Water

Nik

it seems like there is no industry standardized testing methodology for pressure testing radiant piping. From what I have read the decision of using air versus water is mainly related to safety. Are there other issues in terms of accuracy/reliability depending on what is used?



The following is commonly found in radiant glossaries regarding pressure testing:



The introduction of helium, nitrogen, oxygen, or other type of air to pressurize the system for testing is not an acceptable test and will likely result in inaccurate conclusions.



What are the issues other than safety?



Also, there seems to be a huge range of suggested pressures that these tests should be performed at. I have seem as low as normal operating pressure all the way up to 120PSI. I have read that code requires a hydrostatic test at 100PSI.



Is it possible that at low pressure and cold temperatures some leaks do not show up?



Thank you in advance for any information or opinions.

furnacefigher15

air is less messy

I like to use air on a newly installed system for initial pressure testing. For in floor I like to pressurize prior to concrete pour (and during), so they'll no if they puncture a line, and they can tell me.



I fill to 10 to 20 psi compressed air, and listen for leaks as well as take soap to all connections, prior to the installations of floors, drywall, etc.. that may conceal a leak till to late. This is a time consuming process and often requires the use of temporary "jumper" tubing to bridge over radiator or baseboard locations were there are not yet radiators installed. But, the expense of hidden water leaks is much worse.