Help please - how do I connect to old 7/8" pipe?

[dmcc]

I am trying to fit a shower for my aged in-laws and have hit a snag. The hot supply comes into the bathroom being converted to a shower room and I am trying to hide the existing plumbing under floor. I thought the hot supply was through a 22mm pipe but I now find it is 7/8" (or ~ 25mm). Is there an alternative to filing down the pipe end which is embedded in a wall? Does anyone know of a reducing elbow which would do the job? Or any other suggestions?

dmcc

 

[plummerman]

By 7/8th do you mean 3/4 copper? or is it 20 thread copper. 3/4 is smaller than 22mm so no filling required. fittings just slip straight through. 20 thread is a whole new ball game

 

[dmcc]

Must be the 20 thread as it is definitely at least .5mm too big for a 22mm compression elbow. 7/8" was just my guess based on a tape measure. It is a really old installation. Thanks for your reply.

 

[plummerman]

Is the wall of the pipe quite thick? if it is i say it was 20 thread. Can you trace the pipe back to anywhere it changes direction? does it have threaded fitting on it instead of soldered type?

 

[dmcc]

Yes to both your queries. I have been thinking since I asked this that the best solution may be to strip this pipe out and replace it with 22mm. Not what I had anticipated but maybe the easiest solution in a small house.

 

[gas4you]

Have you tried a 3/4" olive in the 22mm compression fitting?

3/4" is about 0.5mm smaller than 22mm.

 

[dmcc]

No sorry we are at cross purposes, the pipe is bigger than 22mm, in fact bigger than 7/8" so 3/4" olive would be going in the wrong direction.poses

 

[gas4you]

Ok, probably my mis-understanding

How about a 28mm-1" converter fitting? Not much difference between the two but then whats 0.5mm between friends

 

[dmcc]

I'm not sure I know what you mean. I would have thought 28mm would be so big the olive would never grip the pipe which is only an annoying amount larger than 22mm. Or am I missing something?

Don

 

[plummerman]

the old inch fitting is smaller than 28mm, so i theory could grip onto your slightly larger 22. Or try undoing the threaded fitting and taking it to bss or pipe center and asking them if they've got anything to help you out. failing that the copper weigh in will certainly help with the payment to re-pipe. either that or a solid night out on the tiles. Always look for a bright side

 

[gasmick2]

you can actually buy 3/4 20th to 22mm soldered fittings i have used them you can get 1/2 20th as well to 15mm i made myself a bumping tool that expands the 22 out to fit 3/4 20th have a shop round i think plumb center used to keep them

 

[tonybhoy]

I've just encountered the exact same problem on both 1/2" heavy gauge and 3/4" or 20 thread (didn't know that was what it was called,thanks).

Way I got out of it was by using a galvanised fitting on the 25MM pipework then a 22MM X 3/4" male adaptor. I was assured by the supplier (industrial heating supplier) that it was suitable for domestic hot water and indeed it worked.

Name of this fitting is, 3/4" Primofit female adaptor and costs about £9 including vat.

On the 1/2" you can buy a philmac type of fitting that can be used on pipe sizes from 14MM to 18MM and this fitting is suitable for potable water.

Name of this fitting is a Polytrans coupling 15MM-21MM and cost about £6 inc vat they also do one from 22MM to 28MM (I think but it's not suitable for domestic hot water-20degree max I think)

 

[tonybhoy]

you can actually buy 3/4 20th to 22mm soldered fittings i have used them you can get 1/2 20th as well to 15mm i made myself a bumping tool that expands the 22 out to fit 3/4 20th have a shop round i think plumb center used to keep them

Guy in the supplier told me another way out was to use a 15MMX8MM copper reducer by sticking the 8MM side into the old pipe and soldering it then use the 15MM side to connect to 15MM copper.

Didn't fancy that to be honest.

 

[doitall]

I am trying to fit a shower for my aged in-laws and have hit a snag. The hot supply comes into the bathroom being converted to a shower room and I am trying to hide the existing plumbing under floor. I thought the hot supply was through a 22mm pipe but I now find it is 7/8" (or ~ 25mm). Is there an alternative to filing down the pipe end which is embedded in a wall? Does anyone know of a reducing elbow which would do the job? Or any other suggestions?

dmcc

Could someone explain what we're talking about

The od of 22mm pipe is 7/8", but what the bit in brackets in aid of.

Or is the OP talking about 25mm being the ID for the old 1" copper.

 

[tonybhoy]

I am trying to fit a shower for my aged in-laws and have hit a snag. The hot supply comes into the bathroom being converted to a shower room and I am trying to hide the existing plumbing under floor. I thought the hot supply was through a 22mm pipe but I now find it is 7/8" (or ~ 25mm). Is there an alternative to filing down the pipe end which is embedded in a wall? Does anyone know of a reducing elbow which would do the job? Or any other suggestions?

dmcc

Could someone explain what we're talking about

The od of 22mm pipe is 7/8", but what the bit in brackets in aid of.

Or is the OP talking about 25mm being the ID for the old 1" copper.

Thought you were in the trade for 50 years?


He's talking about heavy gauge copper ,real heavy gauge copper the 3/4" stuff is about 24mm which is too big for 22MM fittings and too small for 28MM fittings.

You can't file this stuff down or you could if you are mad. The pipe wall is nearly 5MM thick.