How to connect compression fittings

[mm]

I got that valve for copper tubing I posted about before -- thanks for the advice and leads on that -- and it has a compression fitting at each end.

Does anyone flare the tubing enough so that the compression ring and the nut don't come off the tube? Or does that end up making it too big to get into the seat?

And is it true what one web page says that the compression ring can be used only once???

"You can not remove a compression ring from tubing once it has been used. If you can't get a leakproof connection, the tubing behind the ring will have to be cut, and a new ring installed. Though the compression nuts can often be reused, I would recommend against it because the old nut may be slightly deformed and lessen the quality of the new connection."

Is any of this true? I"ve reused the compession ring on the humidifier at least 6 times, every time I've removed the tubing from it. The connection has never leaked.

Does the tubing flare when you tighten the nut and does the tubing have to be cut to remove the ring, just to replace it? Isn't that good, that way the ring doesn't fall off!

Do they even sell rings separately?

Do people really use a new nut when they reconnect??

One url says use plumber's grease for the nuts but the other pages don't say a thing about that. Do you use it?

Can the tubing really be "severed by the compression sleeve" if the nut is tightened too much, like another page says.

Do you use "thread seal tape"? One page said not to and the other page said the opposite!

I'm confused!

[trader4]

A compression fitting and a flare type fitting are two different things. Compression is far more common today and you do NOT flare the tubing. The flare type fitting has a tapered shaped on the male end that mates with the flare. Compression does not.

Sure, if you flare it, it very well could be too big to fit into the fitting.

It may have worked, but you were lucky. If the fitting is properly tightened, which usually means using a back-up wrench to hold the other half, the ring winds up tight on the tubing and should not come off again if taken apart.

Yes

No, unless there is evidence something wrong with it the nut and fitting can be re-used.

I haven't used any lube and haven't had problems. But it sounds like lube could help it compress. Not sure having WD40 in my fridge line or having an oily fitting to work with is worth it though.

I don't see how it could be severed either. It should not be overtightened to begin with.

No tape, that's for sure.

[jw]

No flare, the ring wont go on. Just slip it on, into the valve, keep the pipe pushed in while you tighten the nut. Tighten well, but dont over do it.

Yes. You'll never get it off. You can buy new rings separately.

Most of the time the nuts are fine to be reused unless someone stripped it or deformed it.

See what I said above.

The tubing does not flare. The ring embeds into the tubing. You can unscrew the nut and put it back again, but if you need to remove the ring, you have to cut off enough to remove the nut. Alwasys leave enough slack in the pipe so you got a little spare to work with.

Yep. Any good hardware store should have them.

Only people who f*ck up the original nut.

Not needed. It wont hurt on the threads, but DO NOT put in on the pipe by the ring.

I never seen one sever, but I have seen them deform so bad from over tightening that they will never seal.

NO

I can tell :)

[mm]

Thanks to you, JW, and stormin and Trader. I think I'm ready to go now.

In a way, things were easier in 1985 when I first put this together, no one but the hardware store guy to ask questions of, and it turned out okay, but now I wanted to do an even better job.

[trader4]

God help you if you ask the hardware store guys at the local ACE here anything. There is one idiot there who immediately runs up to you as soon as you walk in the store and wants to get involved in "helping" you. For example, I was looking for a small water pressure gauge. First off, they didn't even have any. But along the way he questioned me whether it was a well system or city water, then proceeded to tell me that city water operates at 2 PSI.

Another time, I was looking for screws and he waltzes over and asks to help me. I tell him I'm looking for #10 round headed wood screws. He looks at me like he never heard of such a thing. Then he asks, what do u need them for? I felt like telling him to shove in your mama's behind. Next he tells me to use sheet metal screws, because that's what he uses. Of course, I could use them in a pinch, but they aren't what I really want, nor intended for the application. If the ass weren't there, I'd have found what I wanted 5 mins ago. One can only imagine what happens with the advice the jerk gives to novices.

[mm]

Maybe you could make a tv show out of this.

Three hardware stores have closed on the shopping street near me since I moved here 27 years ago. One was a real hardware store and though I didn't ask for much advice, I think the boss knew a lot. He said he didn't want to stay open late and on weekends, so he closed. The other was a small version of a big box store, before biggg ones existed. I can't even remember the third one.

There is another one a mile farther out, and they've been forced to concentrate on lawn-mower repair and tool rental, all the way up to frontloaders, and things requiring service. I hope they stay in business, for the occasional time I need them. They sell motor brushes, for one thing. They even hired a girl in her 20's who seems to at least know what they have and where everything is, but I don't epxect her to know what to do with things. The old man is still there, but I forget the last time I asked him a question.