Wrong Size 3/4" Imperial Tube ?

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R

rfear

Hi Everyone,

First post, so go easy on me. I have searched to see if this has been asked before but no joy.

I ordered some 3/4" copper tube to replace what I thought was original 3/4" copper tube in my bathroom, at the same time ordering some 3/4" imperial olives. ( It seemed the simple solution, rather than having to change out a t-joint ).

The old pipe OD is 21.5mm, the olive ID is 21.0mm but the 3/4" tube that has arrived measures 19mm OD ?

Now, 3/4" is literally 19mm. So, what do I need to order to get what I thought was 3/4" tube but needs to measure 21mm (OD) to match the olives ?

R.

😕
 
what are you trying to rplace?atee? normally you would join on to the 3/4 with a 3/4by22 soldered adapter or a 22mm compression fitting with a 3/4 cone
 
Which country are you from. I am guessing it is not the UK by what you describe? Here in the UK, all new copper tube is 22mm and you use a 3/4" compression cone in a 22mm compression fitting to make it fit, or like previously stated a 22mm x 3/4" conversion soldered fittting.

A 22mm fitting and olive will fit onto a 21.5mm OD pipe no trouble at all. If your old pipe was this size then it was probably desingnated as 22mm not 3/4", as you correctly state 3/4" is a smaller OD. I have never noticed 3/4" pipe for sale here recently but then again I've never looked for it.

I would use soldered fittings.
 
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🙂 let me try to explain 🙂

I am in the UK and have recently moved into a house built in 1909. The plumbing does not comply to modern metric standards, but at least it is copper. I am assuming, until proven otherwise, that the hot water pipework in question is old imperial tubing.

A leak beneath the bath had allegedly been mended, but not very well. The pipe run in question begins at a compression fitting equal tee, for the sake of argument lets call it 3/4". From here one outlet from the tee runs to the hot water tap under the bath. The original installation was a mixture of imperial pipe, 90deg bends ( compression fitting again ) upto a tap connector. It was pretty much leaking everywhere, so I set about reducing the number of joints.

I now have a flexible, push fit tap connector from the tap, pushed onto new 22mm tube, joined to the original pipe using a metric / imperial adaptor coupling ( 22mm x 3/4" ). From here the original pipe goes back to the equal tee.

I sorted all the previous leaks, however, the equal tee joint is weeping ( used the original olive and tried to remake the joint ). New 22mm pipe will not fit into the equal tee ( too big ) and I'd rather not remove the equal tee as that would mean compromising the 2 good joints and the tee is close to the floor and anymore leaks would involve lifting floorboards etc.

So, simplistically I thought if I could replace the old tube, life would be simple, except 3/4" pipe today doesn't appear to equal 3/4" pipe of yesterday ???

So, how come a 22mm x 3/4" adaptor and a 3/4" olive measures 21mm inside diameter and fits to the old original pipe, but modern 3/4" tube measures 19mm outside diameter ?
 
Some of the really old copper was 3/4" ID. The old standard of imperial copper was not established until the 1930s I believe.

Have you tried to remake the joint in the tee with jointing compound or PTFE? This would be my first thing to try.

Will a 3/4" compression cone fit into the tee?
 
3/4" ID - that might explain it.

I was coming round to a similar conclusion - remake the joint. It already has jointing compound but if I check the pipe has not been deformed and use a new compression ring I might be lucky. Seems simpler than trying to find some old pipe.

Last resort is to replace the old fitting with a modern metric fitting and couple to the old pipe. Not as bad as it sounds, given the fact that I have the ceiling off below the bathroom, repairing the water damage.

Thanks.

Yep, confirmed it. Original pipe is 19mm ID, modern pipe is 19mm OD.

I assume the chances of sourcing 19mm ID tube is remote.
 
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The only way you'll find any is if anyone like me has saved a bit - I always keep any old lengths of oddball or very old sized pipe and fittings if I come across them. You never know when it might come in useful. I have a box of such items and it can be so handy at times.
 
WHPES said:
The only way you'll find any is if anyone like me has saved a bit - I always keep any old lengths of oddball or very old sized pipe and fittings if I come across them. You never know when it might come in useful. I have a box of such items and it can be so handy at times.
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If your shed is anything like mine you'll never find it and when you do it'll 2 yrs down the line 😀
 
I have come across some very early copper in townhouses round here. My 1902 plumbing book describes working with copper tube.
 
WHPES said:
I have come across some very early copper in townhouses round here. My 1902 plumbing book describes working with copper tube.
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it probably does but it would have only been used on mansions and commercial buildings at that time All around the west end and city of london where i did my appreniship it was all barrel and lead tails some of the newer buildings had copper tails to basins etc and copper wastes seemed to have apearred in the fifties and sixties
domestic properties always lag behind unless like plastic its cheaper
the early small bore heating systems in the fifties were mostly barrel giving way to copper in the early sixties
 
WHPES said:
The only way you'll find any is if anyone like me has saved a bit - I always keep any old lengths of oddball or very old sized pipe and fittings if I come across them. You never know when it might come in useful. I have a box of such items and it can be so handy at times.
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Hi , I've got a 3/4 " Alkathene pipe from a well and do you think I can find a

3/4" equal Tee comp. - that is imperial which takes 26.8 mm as opposed to

28mm metric , I wonder if a 28mm fitting and an imperial copper 3/4" olive

would work , I don't really want a Philmatic Tee as this is too bulky. any

advice on suppliers or prehaps a really old plumb shop if it exists . TEE
 
I'm a little confused by your request. Are you meaning that you require a copper reducing insert to go from a 28mm tee to a 3/4" pipe? The 1" x 3/4" reducing inserts were a funny shaped copper thing which bit into the pipe when tightened (and wasn't very good), and no I don't have an [intact] one. I doubt it would work in a 28mm fitting even if you do manage to find one as they were designed for 1" fittings.

Can a 3/4" x22 cone fit over your 3/4" alkathene pipe and go into a standard 22mm tee or do you have inch pipe at the other ends which you are trying to meet up with?

You won't find anything other than a Philmac universal fitting or the standard Plasson ones with the imperial adaptors (3 types in different colours depending on wall thickness) at most merchants. Your only hope is by asking around, Farmers are probably the people who are most likely to have odds and ends,
 
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I recall doing a rip out job on a huge stately home back in 1998 near Oxford and I was only there to remove the heating system.

at the time I priced it at £2500 for 3 blokes over 2 weeks and thought the price was a bit tight.

When I first inspected the job there were 1/2 to 1 1/2 heating pipes every where and I thought they were all galvanised. this pipe work turned out to be thick walled copper pipe with cut threads screwed into brass fittings. Needless to say I stopped worrying about the price
 
could it be screwed copper, there was quite a bit around back in the early fifties.
 
Hello Wphes , Basicly whats on the pipework to the pump in this small housing
are brass elbos, Kuter 3/4" and ther'e fine I can get the 3/4" copper olives
ok but then to split the supply I would need a Tee , DZR , water is acidic
I could use 28mm with imperial olives that fit tight on the Alkathene plastic
pipe and will clamp onto the pipe when fitting is tightened and prehaps the
tad over 1mm gap is not going to notice providing the pipe is kept straight.
it would have been so simply if 3/4" was still avaliable , BES only go to 1/2"
imperial in brass comp. Tees . I need to look round boot sales and junk shops
maybe , I certainly will keep any imp. fittings I take off now ! -- Alkathene
is LDPE type , id of 19mm + and od of 26.8mm wall thickness of 3.5 + so it's quite an odd ball size to adapt . -- Philmac is probably the safest route
if I don't want leaks . T
 
Hi
I am trying to do some tests on 3/4 inch (19mmID) pipes and cant get hold of a sample. does anyone have an offcut (say 1-2m) or know where I can buy some?
thanks
 
I belive copper was brought out in 1936, all sorts of sizes and gauges, 18gauge is was I was used to and wht you have, a bugger to conect to, we used to take a piece of out of the fitting and braze 18 to 3\4 and later to 22mm by far the secure way.
Richard
 
If its not screw gauge copper. Have you tried drifting the old pipe out to form a socket and sleeve for a modern pipe size?

The walls on the old pipe where thick,so I suppose they will take a bit more drifting out than modern pipe. Should be okay if you anneal it first.

Must admit I am not a fan of socket forming but if its all there is!
 
Hi I am trying to do some tests on 3/4 inch (19mmID) pipes and cant get hold of a sample. does anyone have an offcut (say 1-2m) or know where I can buy some?
thanks
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Yes, and no - I need it in case I ever get stuck. In time you will come across some when you strip it out. What are you wanting to test?
 
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