Pressure testing new radiant system

schultzey11

I'm working on pressure testing a brand new system I'm working on. Curious what the communities thoughts are on the fiber washers included with a honeywell mixing valve? I've tightened these things as tight as I possibly can without fear of breaking them and they still seem to be leaking when I test at 20 psi air.



Should I get a bigger wrench?

A little more info, I soldered an adapter on so these can go to 3/4" pex. Some of the solder worked it's way onto the flat - sealing surface so I used some emery cloth to remove being careful to make sure I didn't create low spots. All sanding done by hand so as good as I could by eye.

The pex fittings where not soldered while on the mixing valve so "heat" from soldering is not a factor.

Install photo.

hot_rod

It sometimes helps to wet the gasket first, then install them.
It should not take much tightening on a gasketed connection, most times they are over tightened and then crushed to where they will not seal.

You could also disassemble, dry off and use some teflon thread dope

schultzey11

I think I'll try wetting them.

If I go pipe dope route, Just use a small amount on both sides of the washer so that doesn't wreak havoc on the valve down the road?

Jamie Hall

If I may, I'd point out, too, that fibre washers are often meant to expand in place slightly when wet. A dry fibre washer is going to leak air, pretty much inevitably.

Ironman

Yup, let 'um soak in water for at least 5 minutes.

schultzey11

I've played with these most of the weekend only to continue watching them slowly leak - definitely did several 5 minute soaks, but that was after I dry testing them prior to this post.

Should I fill the system anyways and hope they seal or replace with new ones and try again?

hot_rod

Once they have been over torqued, they should really be replaced. But a dab of pipe dope could also take care of the drip. Dry them and the surfaces first.

Zman

Most of those can be replaced with a rubber union washer, at least for the air test.

schultzey11

I looked at my local Menards tonight, didn't see anything. I'll have to look again, thinking the same thing. So rubber for air test and then go with new fiber washers once all other leaks have been fixed?

What's the torque on these things? Nothing stated in the manual. Hand tight plus 10° ish with a wrench?

I'm still thinking of giving @Hotrod's advice above a whirl.

Big Ed_4

Just to add.... I always leave a radiant job wet and pressurized for a leak check ... This way any future contractor that drops a knife or one with a haphazard drill has to take responsibility and it could be repaired before the job is done .

hot_rod

Water meter rubber gaskets will fit, fairly easy to find.