Leak! Street elbow and compression fittings!

[nv_london]

Dear all,

after soldering a piece of 22 mm copper pipe into the female end of a 90 degree street elbow I tried fitting the other end (male) into a compression fitting. This part of the joint now leaks. I un-screwed the nut, wrapped some PTFE tape around the thread and re-tightened. It still leaks.

Now I'm wondering if there's enough length on the male part (no jokes!) to properly reach into the compression joint?! - Should this make a difference? i.e. does the male part have to be pushed right in to the compression joint so that it can't go any further? If so, I don't think it is going all the way in due to the nut hindering it because of the bend in the elbow.

Hope all this makes sense and any help or solutions would be much appreciated.

 

[Softus]

I un-screwed the nut, wrapped some PTFE tape around the thread and re-tightened. It still leaks.

Remove the tape from the threads - it does nothing other than get in the way.

Now I'm wondering if there's enough length on the male part (no jokes!) to properly reach into the compression joint?! - Should this make a difference?

Yes. But it would be an unusual street elbow that wasn't long enough.

Just measure it.

does the male part have to be pushed right in to the compression joint so that it can't go any further?

For mechanical strength and longevity, yes it does.

However, to seal, it merely has to reach past the olive.

If so, I don't think it is going all the way in due to the nut hindering it because of the bend in the elbow.

That's why you need to measure the insertion depth, and the length of the straight part, and compare them.

 

[nv_london]

thanks for the reply and the advice.

I know that the male part doesn't reach all the way into the compression joint. - Actually, it does on it's own, but it doesn't once the olive and the nut are on the male part, because the nut now gets in the way.

I'm sure it's this which is causing the leak, 'cos the other compression joints I did (with straight pieces of pipe) don't leak.

Should I look to use a different size nut, or is it better to extend the male part of the elbow?

 

[giblets]

I have found that the end feed street elbows are a little short on the male end so I always use solder ring (Yorkshire) ones if connecting into a compression fitting.

 

[Softus]

I know that the male part doesn't reach all the way into the compression joint. - Actually, it does on it's own, but it doesn't once the olive and the nut are on the male part, because the nut now gets in the way.

In that case it's possible that you're inserting it too far, and causing the elbow to cant over and thereby prevent the olive seating properly.

Should I look to use a different size nut...

I don't think so. Just draw the elbow back.

Have you measured the insertion depth with the olive and nut in place?

...or is it better to extend the male part of the elbow?

What?

 

[nv_london]

Have you measured the insertion depth with the olive and nut in place?

- Yes, it doesn't reach all the way into the compression joint.

or is it better to extend the male part of the elbow?

i.e. is it better to solder on an extra length onto the male part which, even when the olive and nut are on it, still manages to reach all the way into the compression.

 

[doitall]

You put the nut and olive on the pipe and do it up hand tight, then push the elbow right in to the fitting, use an jointing compound on the olive

 

[wiggikins]

Have you measured the insertion depth with the olive and nut in place?

- Yes, it doesn't reach all the way into the compression joint.

or is it better to extend the male part of the elbow?

i.e. is it better to solder on an extra length onto the male part which, even when the olive and nut are on it, still manages to reach all the way into the compression.

If that is the case , then why not just use an ordinary elbow from the outset!!

 

[Gunslinger]

as someone pointed out, yorkshire street end elbows tend to have a longer plain end on them, or i think you can get extended street elbows, although they are not so common, i know i've got some i picked up from somewhere because i knew they would be handy at some point when i saw them

 

[Gasguru]

Good plumbing practice would not result in having to fit a street elbow to a compression fitting....since they often leak although it sometimes takes several months before it shows.

 

[Softus]

is it better to solder on an extra length onto the male part which, even when the olive and nut are on it, still manages to reach all the way into the compression.

Yes. Street elbows into a compression fitting are always a pain the neck, because of undoing the capnut.

 

[nv_london]

Thanks Softus.

(Hindsight is a wonderful thing wiggikins!)

 

[mosaix]

You put the nut and olive on the pipe and do it up hand tight, then push the elbow right in to the fitting, use an jointing compound on the olive

Everyone seems to have ignored this post.

 

[Softus]

Everyone seems to have ignored this post.

Not really, it's just that some people like jointing paste, and some don't.

 

[doitall]

Everyone seems to have ignored this post.

Not really, it's just that some people like jointing paste, and some don't.

But I would guarantee it didn't leak if he followed my simple instructions