Prestex fitting thread problems

[EnorMouse]

I am in the process of re-routing the plumbing to a wash basin in a residential property that I rent (this means that I can do a limited amount of work, but not rip the place apart).

The cold water feed comes up through the floor and immediately goes into a 15mm compression elbow, before heading off across the carpet, several inches out from the wall. I now want it to go straight up, so that I can then route it along the skirting, replacing the existing stop valve with a modern service valve.

The floor has been hardboarded over so I can not get access to the pipe in the space under the floorboards and there is absolutely no play in the pipe so I can not cut it back and install a new fitting and I am nervous about damaging the pipe if I try to cut the existing olive off, particularly as there is no space to work and the possibility that the pipe might drop down making the fitting of a new joint impossible.

The problem that I am encountering - I hit it first on the hot pipe but managed to get around it - is that the existing elbow (and accordingly the remaining cap nut on the pipe) is a Prestex 15mm fitting of uncertain age and the thread is both larger in diameter and finer in pitch compared with the 'standard' compression fittings that I have.

I can not find Prestex fittings at any of my local plumbers merchants, but I have found them online. Can anyone tell me if the currently available Prestex fittings have the same distinctive thread as my one or have they now adopted the standard thread. I do not want to pay out over £10 (including delivery) if the fitting is not going to match my old one.

Anyone any suggestions as to how I get around this? The only thing that I can see to do is to stick another elbow immediately after the existing one, but putting an S-bend in the pipe is not as aesthetically pleasing as coming straight up.

All assistance appreciated.

EM

 

[bengasman]

Get an olive removing tool, take olive off, and solder.
Sounds like a lot of work, cost, and risk, might be cheaper in the long run to hire a pro.

 

[Dick Puller]

I've never seen someone write so much about a thread on a Prestex fitting!!

Never laughed so much since the wife died!!!

 

[EnorMouse]

Get an olive removing tool, take olive off, and solder.
Sounds like a lot of work, cost, and risk, might be cheaper in the long run to hire a pro.

I have thought about this, but am not sure that I can get/keep the cap nut far enough back to even get such a tool in. I have no idea how someone did it in the first place, but I was thinking that I would be forced to hold the spanner on the nut fixed and turn the fitting - that's how little clearance there is.

EM

 

[bengasman]

In that case, don't risk it. Unless you can see about 50mm of pipe above the floor, call a plumber.
Make sure you clearly explain over the phone that part of the problem is simply not having enough pipe to allow for a mistake.

 

[EnorMouse]

I've never seen someone write so much about a thread on a Prestex fitting!!

Never laughed so much since the wife died!!!

If you want good advice - explain the problem fully.

If you think that the cold water pipe deserves a laugh, you should have been watching when I first discovered the problem on the hot pipe. I had used an ice plug, but because there was only a couple of inches of pipe above the floor, it was both much smaller than normal and too close to the work.

Despite this, thing were going fine, until I tried to attach the new pipework and new cap nut, to the Prestex elbow. Would not go on! Had I crossed the threads? Pushing, pulling, twisting - but it just would not go on. Of course the ice plug starts to melt and once it starts the hot water comes up the pipe and hey presto melts the plug entirely. Hot water starts jetting all over the place. Fortunately I could get the old pipework back into place and as the valve and tap were open, the water took the path of least resistance and I was able to get the fitting watertight before I flooded the place and in particular the flats below.

Unfortunately the temperature of the water was such that I ended up with some burns, from holding the pipe back in place, but the blisters have gone now. Managed to salvage a matching cap nut from further up the plumbing, so that when I did it a second time, it worked fine.

Having said that, I have no wish to repeat the performance, so if trying to get some specific advice results in some jocularity, feel free to enjoy yourself. Hope that you enjoyed the above - not quite up to the old 'man and the barrel of bricks' standard - but it has taken me a while to see the funny side.

Enjoy

EM

 

[bengasman]

Just ignore him, he is nothing but a troll that is exactly what his "name" suggests.

 

[Deleted member 105431]

if theres not enough room for an olive cutter then an olive puller works a treat.

 

[DP]

Look elsewhere on pipe runs for a straight Prestex fitting. If you find one (am sure you will), replace that with a new coupler, Failing that send me email having measured the diameter of threaded portion- might have a fitting you are looking for.

 

[Legion]

Just ignore him, he is nothing but a troll that is exactly what his "name" suggests.

Dick puller:
sorry I did not get back to you with my details here you go;
Gas; full ACS Domestic & Commercial.
Oil; all Oftec qualifications for pressure jet burners.
Time-Served in Domestic/Commercial Plumbing & Central Heating.
Full range of C&Gs.
Technical Grade Plumber at the age of 21.
Steel pipe fitting & welding qualifications.
Part time Lectured in Roof Lead Work.
Have been a Master Plumber for 30 years.

Bengasman:
Now that is really very impressive.
Not only good theoretical knowledge as a boy, and decades of experience, gone back to school after that to keep up to date.
You are indeed miles ahead of myself, so far that I did not even know of a single lecturer in leadwork existed in the entire country.
I hope you will soon join us in the cc, we could really do with somebody with that much knowledge.

Sorry Ben.

 

[bengasman]

Sounds more like somebody listing every relevant qualification that he could find, then an actual achievement.
I do remember that bit; took him about a week to come up with it, but still need to see him in CC.
If memory serves: because he could not be asked to give information for free as it had taken so much time and money to acquire.
He is a troll allright.

 

[JayJay1978]

Sounds more like somebody listing every relevant qualification that he could find, then an actual achievement.
I do remember that bit; took him about a week to come up with it, but still need to see him in CC.
If memory serves: because he could not be asked to give information for free as it had taken so much time and money to acquire.
He is a troll allright.

He is a bully boy and a screwfix reject

 

[Legion]

Know`s what he`s on about and a good laugh in my book, and No, I am not him, or charliebamber.

 

[glasgowgas]

Know`s what he`s on about and a good laugh in my book, and No, I am not him, or charliebamber.

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[bengasman]