Radiator Union Alignment

garfungle

I've just gone through the process of installing new TRVs on three of my radiators. I'm double checking everything and I was curious about the alignment of this one union. I'm not entirely sure if I'm just being nitpicky or if I should go back and redo this radiator alignment. It looks like it's slightly crooked. On this radiator, the valve didn't perfectly line up, so I had to shift the radiator around a little. Would this be considered a crooked union and should I just redo the alignment? I'm a noobie at this, so it's hard for me to judge if this is crooked or good enough.

Thanks

delcrossv

What's with the tape under the union nut? Those aren't taped or doped. Take the tape off and undo the nut. Do the faces of the union align? If not, readjust. The faces of the union make the seal, not the threads.

garfungle

Yea, everything was aligned before I tightened the nut. I don't believe it's cross threaded either. I didn't think it mattered whether the straight threads were taped or not. I was just using the tape as a lubricant. Is it a big no-no or against code to tape threads? I just figured it would help tighten the nut and prevent it from seizing in the future.

pecmsg

A little never seize on the face and the back of the nut is all that's needed. Tape or dope on the threads of a union says you don't know what you're doing.

delcrossv

Not a code issue, but more of a why do it issue.

If the union doesn't leak, you're good.

Jamie Hall

And you don't need lubricant to "help tighten the nut". A union nut on a low pressure system like a residential radiator should be on hand tight, and then no more than a quarter to half a turn beyond that. Never more than that. It it leaks, tightening the nut isn't going to help — you will need to realign the union (no angular or lateral displacement at all!) and then thread the nut on to keep it that way.

EBEBRATT-Ed

It looks fine, the tape will hurt nothing.