help with pressure testing.... 101....

[atvalaska]

Ok.... I'm on my way here, a bit more wiring and such...I have 1 1/4 pex S&R lines @ 120' total length (underground thermo pex) and on each end "the boiler hook up/boiler shed " ... and... "the shop with 4way valve etc" which comes out to about 50' of 1" pex ... Add about 10' of iron and copper mixed in . I used my air compressor and took the air to 18 and it held over 24hours (falling 2 psi) 3 days latter it was down 3 psi BUT when I heated up my shed from 25 deges to 45 so I could work in there, the numbers came back up to 17 psi ....THIS week>.....so after I finished my work in the shed yesterday """I got every thing from my shop to the boiler shed ( a walk in freezer btw ) all hooked up, all the lines valves open etc and ran the air to 25 psi last night at 7pm.......... this morning at 6am ...I'm down 2 psi .....SO???? do I account for the temp differences of day vs nite... 30deg days ...nites 23 degs AND "pex stretch/flex" ...I'm not going to add any air for a couple days, as the weather is to stay about the same I don't feel I need to add "more air" as my boiler will "blow off at 30psi"....where to go from here (my fittings are all threaded with blue monster and the pex is all Uponor propex

 

[SIERRADMAX]

Lower temperatures reduce air pressure. Higher temps increase. I'd say a 2 psi drop... You're ok.

 

[salecker]

I tested all my stuff to 60-80 psi.
My dealer always said you want to get rid of the wimps before you add water.I used Hemp on all my threaded joints,no leaks yet.
Thomas

 

[atvalaska]

I used monster blue stuff.....no hemp for me

 

[woodsmaster]

I also tested to 60 psi. 2 psi could be temp difference or might be a slow leak. more time will tell.

 

[salecker]

If i remember correctly i didn't see much in the way of pressure differences when the temp changed.I would leave the test preasure in as long as i could,sometimes a week or two depending on what i was working on.
Thomas