Old 3/4'' 20mm copper.

[cdavie2002]

Is it ok to use a 22mm compression fitting on (20mm)/(3/4'') pipe to connect to modern everyday 22mm copper? It's holding this far, took a bit of torquing!

 

[lame plumber]

if you use a 3/4" olive

 

[Killy Bing]

*facepalm*

you need to use an imperial 3/4 olive......

tell us how long it holds for

 

[BN9Pete]

Is it ok to use a 22mm compression fitting on (20mm)/(3/4'') pipe to connect to modern everyday 22mm copper? It's holding this far, took a bit of torquing!

Its holding so far?
see what happens when you turn on the water:confused5:

 

[PlumbBobBob]

as said it really needs a 3/4 olive which are readily available

 

[snowhead]

Answer = NO

It took some "torquing" to squash the 22mm compresion ring so it just touches the 3/4" pipe, not enough to grip it.

She's gonna blow..

 

[cdavie2002]

Water has been on all day, dry so far....

Il get some 3/4 olives tomorrow, just incase.

 

[cdavie2002]

Stupid question....

If using a smaller olive in a 22mm compression fitting, do I just need to apply extra turns?

Thanks

 

[lame plumber]

I agree it is

 

[townfanjon]

Its holding so far?

Chuffin wouldnt if I had used one

 

[snowhead]

Stupid question....

If using a smaller olive in a 22mm compression fitting, do I just need to apply extra turns?

Thanks

No more than normal once the slack has been taken up in the fitting.

 

[tom609]

I wouldnt go to bed or go out without turning the water off or you might find a rather large puddle on the floor or maybe even the ceiling on the floor if the pipe is on the 1st floor

 

[lame plumber]

theres yellow flood warnings all over tonight and one red one in your house

 

[Best]

A 22mm olive can & will do the job on 3/4" pipe if it is fairly beefy type, like a brass conex olive. They are done that way by lots of people.
It will be more likely to angle on the pipe though & needs to be compressed carefully.
But why would you? Better using a proper 3/4" olive.

 

[kimbo]

I have just renewed some black pipe marked 3/4inch and a 3/4olive wouldnt go on it. I bought a 3/4inch to 20mm connector followed by a 20mm to 1/2inch stopcock.

 

[Ray Stafford]

I have just renewed some black pipe marked 3/4inch and a 3/4olive wouldnt go on it. I bought a 3/4inch to 20mm connector followed by a 20mm to 1/2inch stopcock.

But you are talking about black poly aren't you? OP is talking about 3/4 copper.

If it were me, I wouldn't rest easy until it had the correct olive on it.

 

[Dannypipe]

Got to speak as I find. I will always use a 3/4 olive, or solder an adapter, but a 22mm olive will seal quite often. That's from experience as I did it myself in a miss spent youth. Rebel.

But if it blows, you'll only have yourself to blame. I would never, ever do it now. Genuinely.

 

[kimbo]

Dorry didnt read post properly

 

[Best]

I have just renewed some black pipe marked 3/4inch and a 3/4olive wouldnt go on it. I bought a 3/4inch to 20mm connector followed by a 20mm to 1/2inch stopcock.

Polythene pipe will be called 3/4" but olive needs to be larger for polythene size.

 

[tom609]

Got to speak as I find. I will always use a 3/4 olive, or solder an adapter, but a 22mm olive will seal quite often. That's from experience as I did it myself in a miss spent youth. Rebel.

But if it blows, you'll only have yourself to blame. I would never, ever do it now. Genuinely.

Really ha ha (joking)

 

[Dannypipe]

I hope so!! At least I think I have done it in a miss spent youth. I could completely be imagining that!

As I said, I will sweat an adapter on now 9/10 times, and if not, I keep a couple of 3/4 ollives on board.

 

[Ray Stafford]

We sell thousands of 3/4 olives and EF metric imperial adaptors.

If there was a safe and reliable way of doing it without spending money, I am sure that our er... thrifty customers would have found it by now...

 

[tom609]

always have imperial to metric fittings in tha van along with imerial olives

 

[Dannypipe]

Next bit of 3/4 pipe I find I'm double checking.....could be in for a long wait. I did find a pipe size that I've never ever come across before. Found it about a month back. Leaking joint on a 10mm compression. Took it out, and went to replace it. (long story short, the pipe wasn't 10mm or 8, or 12) but some random size in between 10 and 8mm.

So I just had to remake the joint that was there with a new olive, and ptfe on the olive. (This was ten at night).

 

[helpsy]

always have imperial to metric fittings in tha van along with imerial olives

Same here. I have had times where put 22 brass olive on 22 pipe tightened up and pipe slides out!:blush2::blush2:. Not had my spinach!

 

[Dannypipe]

Same here. I have had times where put 22 brass olive on 22 pipe tightened up and pipe slides out!:blush2::blush2:. Not had my spinach!

Hmmmmmm, perhaps I am imagining this! I'm not known for having popeye arms myself!

 

[helpsy]

Next bit of 3/4 pipe I find I'm double checking.....could be in for a long wait. I did find a pipe size that I've never ever come across before. Found it about a month back. Leaking joint on a 10mm compression. Took it out, and went to replace it. (long story short, the pipe wasn't 10mm or 8, or 12) but some random size in between 10 and 8mm.

So I just had to remake the joint that was there with a new olive, and ptfe on the olive. (This was ten at night).

9mm I guess ! Lol

 

[Dannypipe]

Yeah, well we all carry around some 9mm fittings am I right!? LOL.

 

[tom609]

I thought that but thought it cheesy ha ha

 

[Best]

Next bit of 3/4 pipe I find I'm double checking.....could be in for a long wait. I did find a pipe size that I've never ever come across before. Found it about a month back. Leaking joint on a 10mm compression. Took it out, and went to replace it. (long story short, the pipe wasn't 10mm or 8, or 12) but some random size in between 10 and 8mm.

So I just had to remake the joint that was there with a new olive, and ptfe on the olive. (This was ten at night).

Had to be 3/8" copper pipe! - it is just slightly smaller than 10mm & was used until the early 70s.
It tends to be better, harder pipe also. There was still some brand new 3/8" about which I think was used for car brakes perhaps ?
I still have a quality 3/8" bending spring which actually tight fits onto 10mm pipe.
A really meaty 10mm olive will do the job, but guess you could have used flared fitting.

 

[Dannypipe]

Thanks, I know for next time.

 

[Killy Bing]

Danny. Wade fittings will seal imperial on the smaller sizes.

 

[AWheating]

im the same as danny, ive used plenty of 22mm fittings without a problem in my younger days. Probably lucky that the fittings/olives where alot better made i guess. Ive seen what happens when a 22mm fitting pops off a 3/4 pipe when a work mate at the time did it. The damage come to many thousands of pounds. Not ever worth the risk when a 3/4 olive costs very little, just carry a few on the van.

 

[Mike Jackson]

I did a standard to combi boiler swap a couple of years ago. The system was about 40 years old and the guy that had done the previous swap had used a 22mm compression on 3/4 pipe. The system was very low head and when I pressurised it the fitting blew off. Luckily it wasn't on a low point of the system so not much water came out or i could easily have flooded the flat below.

 

[Centralheatking]

I have mixed up some refrigeration fittings with my normal plumbing ones - it is a nightmare CHK

 

[Reg Man]

Don't bother with compression, the imperial pipe rattles around the metric fitting. Just use a CU1M for the old boys or YS1M or end feed equivalent soldered fitting with lots of steel wool to clean the old pipe up before hand.