Issues with unscrewing 3/4" imperial pipework!


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Hi,

I am hoping for some advice from you good fellows! I have tried to add a picture, hopefully it has come out below.

It will probably be helpful if I add that I do not have a blow torch!

I am wanting to replace my upstairs toilet. Ideally I would like to connect to the right of the stop cock which is above the floor boards in the toilet room. The present pipework is 3/4" imperial. This pipework then continues onto the cistern. Am I correct in thinking this is lead piping?

One concern I have is if I put too much pressure on the attempt to unscrew the piece of pipe to the right of the stop cock a split might occur in another joint along the pipework, i.e. to the left of the stop cock, causing a leak. Also, if I do manage to free the pipe the attempt may wreck the thread, meaning I cannot then screw in a 3/4" x 15mm reducer part. A quick aside, with the pipe I need to unscrew, is that anti-clockwise?

Now, if I wreck the thread or cannot unscrew the pipe, I can still feed cold to the new toilet by coming off a metric cold pipe next door in the bathroom. However that still will leave the open imperial pipe, after a failed attempt.
I have turned off the stop cock by hand and with some extra effort with an adjustable spanner. But, I am still getting the occasional drip in the cistern every half hour.
A question I have is: can I keep tightening the stop cock with the spanner, or will this damage the valve, thus producing a greater amount of water coming through?
If I just decide to feed the toilet from the metric pipe next door in the bathroom, I still have to cut the 3/4" imperial pipe after or at the stop cock as I want to remove the old piping that continues onto the cistern. Once cut at or near the stop cock I can then box in the remaining pipework.

Back to the issue of the open 3/4" pipework, I'd be grateful if someone has any advice on how to fill the open 3/4" pipework, bearing in mind there is a once every half hour drip coming from the stop cock, meaning, in time the pipe it will become full with water from the slightly faulty stop cock.
Will Boss compound with hemp create a secure fill?

Another question I need advice on is: is there a 3/4" x 15mm compression joint out there that has a nut and olive on the imperial side. I can't find one! For then I can just cut the 3/4" pipe and put this 3/4" x 15mm compression joint on.

I have read using a 3/4" olive and loads of ptfe tape can work? What do people think of that?

Also, could someone let me know what is the internal diametre of a 3/4" pipe?

Any advice would be very much appreciated.

Thank you

Paul
toilet 016.jpg
 
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Here Goes :)

The pipe is copper, (scratch the paint off to see) it's hard to tell from the picture but is it 3/4" or 1/2" ? 3/4" I guess as you are talking about reducing it to 15mm.

Is the water flow in the pic running left to right or right to left ? There is usually an arrow on the stop tap. If the pipe runs to the ball float valve on the tank then it is left to right. If it runs in to the bottom of the tank the flow is left to right.

I ask this because mains cold water pipes are mostly 1/2" or 15mm in domestic properties.
and tank feed supplies 3/4" or 22mm.

Assuming that it is mains water feeding through the tap from left to right, is it possible to turn off the water at another tap before this one ? If you can I would replace this tap with a new one,or at least replace the tap washer (don't keep tightening it tighter as the washer will fall apart and not work at all).

If it is 3/4" pipe (again sometimes stamped on the tap) you can use a 22mm x 15mm compression fitting and just substitute the 22mm olive with 3/4" olive you shouldn't need any PTFE tape.

If it is 1/2" just use a 15mm compression socket.the 15mm olive will be a tight fit.

Your biggest problem will be dealing with the water that is left in the pipe and any water passing the old tap washer. if you cannot stop water passing the old tap fit a new ballofix valve on the 15mm pipe straight after the 22mmx15mm reducer for future maintenance of the toilet.

If the water cannot be turned off before this old tap I would turn off the tap as much as I could by hand remove the carpet from underneath have a helper a large tray a bucket and plenty of old towels, an aquavac is very useful to empty the tray without it sloshing about.

Check the flow has almost stopped at the ball float valve, turn off the ballofix valve and using a small length of 15mm pipe connect it to the 22mmx15mm reducer and tighten it up.

Carefully undo the compression nut on the old tap outlet anti clockwise (look at you new fittings they are the same) catching the water as you loosen the joint.(there will be quite a lot of water at this stage as the pipe empties)

Then try your new 3/4" olive on the end of this pipe just to check the pipe is 3/4" before you cut into it.

When everything is under control and the joint is undone cut and clean the pipe a short distance from the old tap nut fit your 22mm reducer with a 3/4" olive and tighten then reconnect the tap compression union back to the old tap.

In the time it took to type this I could have done the job :D

Pete
 
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Imperial pipework!

Many thanks for your reply Pete!

With regard to your message: I've scraped away some paint and the colour of the pipe is grey. I can now see the threaded end that goes into the stopcock. Also, I now believe the pipe is 1/2", and the flow of water is left to right. Also the stopcock is now not letting any water through. The washer must now be working correctly!

I can understand that I can use the screwed end of a 15mm compression joint where it would go into the threaded end of the stopcock. But I'm confused as to how can I use the 15mm compression joint if I can't uncrew the 1/2" pipe from the stopcock.
When I cut the 1/2" pipe in order to get some grips on it in order to unscrew the pipe, if the pipe itself doesn't unscrew, are you saying a 15mm compression joint can still be used on this piece of cut pipe? To me it looks like the nut from the compression joint won't go over the 1/2" pipe?

Have I misunderstood you in this?
 
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Hi
It is hard to get an idea of the scale of the pipe in the picture but
if the pipe is grey It will probably be screwed galvanised pipe (we never see this in my area on cold water supplies)

Check ! 15mm or 1/2" copper is 15mm outside diameter under the paint.
22mm is 22mm OD. 3/4" copper is around 20 to 21mm.
1/2" threaded steel pipe will be a lot thicker than than 1/2" or 15mm copper pipe.

What you need to know is are there any threads showing at position 1 or 2



If there are threads showing at 1 it is threaded pipe if there are no threads at 1 but threads at 2 then it will be compression.

If it is steel pipe you need to carefully unscrew the pipe at point 1 without turning the tap to do this you have to dismantle the pipe if possible or cut the pipe to a suitable length after point 1 and then unscrew it from the tap

Then it is just a simple matter of screwing a 1/2" male iron to 15mm copper adaptor sealing with PTFE tape

Peteand extending to toilet with copper pipe.
 
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Thanks Pete for you continued interest.

I have added another picture with the paint scraped away. And at point 'one' to the right of the hexagonal nut there the pipe is threaded, which then goes into the stopcock.

And as you say I can then screw in a 1/2" to 155mm compression adaptor.
 

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Hi
Thats a much better picture :) your biggest problem now is dismantling or cutting the iron pipe to enable you to unscrew it from the tap.

An angle grinder would be good but watch out for any water still in the pipe and the sparks can make a mess of anything they touch. Be carefull to hold the tap steady when unscrewing the pipe so as not to loosen it and cause it to leak at the inlet side.

Probably also a good idea to fit a ballofix valve on the new pipe after the adapter (already assembled and turned off) so that if the old tap is passing water slightly once this is screwed into the old tap the water will stop .

Good luck.
Pete
 
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Hi Pete, apologies for not writing sooner. I have good news though. Over the weekend I finally got round to cutting the pipe about 5 inches to the right of the stop valve, and then, after securing the stop valve, I got some stilsens on the pipe and found it moved with a bit of effort, then it unscrewed with no further problems.
I can now easily continue on to the toilet with copper.
Thank you for your advice, and support.
 
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Glad to help and it's nice to get feed-back for a change :)

Pete
 

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