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[ran3465]

Just finishing up new Install and getting ready to air test the system. What pressure are you guys putting in the system?

[BoilerHouse]

I built my own boiler and I tested my welds at 3 psi air pressure.  That way, it was very easy to re-weld any leaks by simply venting off air without worrying about drying out the system first.  When I went to hook everything up I didn't test for the final install, I just installed isolation valves in case something should ever leak in the future.

[RSI]

If you mean just the plumbing and not the boiler, it would depend on what heat exchangers you have.

I usually just pressure test with water and use whatever the well pressure is set at. Usually around 60 psi.

The pex and fittings will take over 100 psi with no trouble but not really any point it going that high.

[ran3465]

Thanks guys. Yeah, I'm just wanting to test plumbing, not the boiler. The only thing that worries me are those Logstor compression fittings.

[slimjim]

I wouldn't get concerned with them as long as you don't cut the O ring with the sharp edge of the Logstor when you push it all together, I use my Leatherman to trim off the sharp edge, if they do leak then simply tighten the nut for a better seal.

[LittleJohn]

When I installed my, I was required to pull a permit (NOT HAPPY ABOUT THAT), but all I had to do to pass inspection was to pressurize tubing in slab or underfloor applications (aka hidden once drywall or cement was placed) to at least 50psi, but not more than 100 psi and hold pressure after 24 hours.  To prove that tubing was not comprimised.  It passed and I left pressure in the pipe when they poured cement, so they could tell if they damaged the pipe or not when pouring/moving cement

But since a closed loop (pressurized system) typically operates at 15 psi, with a 35 psi pressure relief valve; you should be fine with a 50psi test.  Just remember, air in pipe will exprand and contrant if heated/cooled;

[ran3465]

Thanks for the help guys, hopefully finish the inside plumbing up tomorrow and fire this thing up!

[LittleJohn]

I have heard in some areas of the country it is illegal to pressurize a radiant system with over a certian number of feet of pipe.  Because you are creating a pressure vessel with a volume in excess of a certain limit, and if pipe fails it is an explosion hazard or something stupid like that.