Pressure test Runtal radiator

mikemac52

Can anyone confirm that during the first time testing of a Runtal radiator it pings like crazy. I was testing at 30psi but it scared the bejesus out of me. Thought I was popping welds. So went to 20psi, which wasn't much better. (Runtal says not to exceed 75psi during pressure testing) My heating system runs at 21-22psi.

mattmia2

It seems to do that as it heats and cools as well.

HomerJSmith

I guess you are air testing it.

A panel radiator, not baseboard? Make sure all the air is evacuated out of it. When operating with water it should quiet down.

I tested a Runtal job which leaked at the connection to the panel. I tried 3 different sealers and finally used original J-B Weld and that did the job.

mikemac52

4' 8 section panel radiator. Yes, air test first. Had to make a couple of connections that were above my pay grade...

Funny you should mention panel connection issues. Was it the side port per chance? The side ports on the panels are not tapped the same way as the bottom ports. Asking Runtal if it was defect or design got no response from them other than to use a good sealant.

The only reason I enquired was that using their stop valve and thread compound on a side port, I ran the valve all the way in till the thread ran into the body with out much effort. The bottom ports tighten normally.

So I loaded up with tape and compound and am testing now. (Runtal recommends compound only)

Thanks for the hint on J-B Weld. I'll see how the test goes today.

hot_rod

If it is a straight thread a tailpiece with a sealing washer is one way to make a connection. Loctite is another way to "glue" together straight threads.

mikemac52

Unfortunately no washer and has NPT stamped on the side.

The Runtal side port has only 2 usable threads, the rest is of a larger diameter and finer pitch. Not sure if that is the way they intended, but we're going to give it a go.