A bad (plumbing) day at the office ... :-(

[Arfa Daily]

Bit of a long post, but stick with it ... :-)

So, today, I finally got the time to go to our burger joint to fit the pressure reduction valve that I bought a couple of weeks back, to stop the 6 bar pressure relief valve ahead of the unvented water heater, from lifting off its seat all the time. For those who haven't seen the valve in my earlier posts, here it is :

has a 22 mm through bore, and comes complete with custom 22 to 15 mm reducing olives, as well as standard 22 mm olives, if you are going to fit it direct to 22 mm pipe. So far, so good. Off goes the water, on go the taps. All drained down, and three inches whipped out of the 15 mm pipe where it's going, in no time. I then fitted the compression nuts over the pipes, and then put the two sections of the reducing olives over the pipe ends, after carefully studying the supplied diagram to make sure that they were going in right. The diagram is quite clear, and the assembly order is exactly as you would expect. Basically, the 'inner' part of the olive comprises a 'straight' section about 5 mm long that fits into the body of the valve. Behind this, there is a 'flare' at about 45 deg that matches a correspondingly angled 'seat' in the valve body. Behind that is a 'conical' section of again about 45 deg, tapering down the opposite way to a 15 mm hole to accommodate the 15 mm pipe. This is the piece of the adaptor, that is going to grip down onto the 15 mm pipe. There is then a completely separate piece that is a brass ring about 5 mm deep, that has a corresponding conical seat inside its front face, and a square rear face to go against the inside face of the compression nut. Unfortunately, the online instruction sheet doesn't show this, so I've had to try and describe it.

What should happen, is that as you pull up the compression nut, the conical seat of the outer ring, presses on the conical taper of the inner part of the adaptor, crushing it onto the 15 mm pipe. At the same time, the 45 deg flare a little further in, should be pulling up against the corresponding seat in the valve body, to form a seal.

Except it didn't. Both sides dripped like a good 'un. The low pressure side was actually worse than the high. And from here on in, the day just got worse. I had been careful not to pull the nuts up more than about a quarter turn beyond where the adaptor had obviously gripped the pipe, as I am fully aware that over-tightening a compression fitting can distort it and prevent it sealing. So I carefully pulled it up a bit tighter. Not a jot of difference. Water off again. Disassembled. Inner part of adaptor seemed to be tightly pinched onto the pipe. I carefully examined the flare and the seat in the valve, but both looked ok and undamaged. However, as that was about the only place that I could see that water could be getting past, I put a good wodge of PTFE tape around the flare, and bolted back up. And still it leaked ...

Thinking that perhaps I was wrong then about where the water was getting out, I then nipped to B&Q and bought a couple of end-feed 22 to 15 mm reducers, that had nice long straight bits at the 22 mm end. As a safety net, I also bought a pair of 15 mm straight couplers. Glad I did ...

With the valve back off, I fitted the supplied 22 mm traditional olives over the reducers, and inserted them into the valve body. Nice fit, and the olive is butting up to the seat in the valve nicely. Out with the cutter again, and a bit more pipe removed to accommodate the new length of the valve with it's reducer 'tails' fitted, and to allow the original reducing olives to be removed, as of course, these are now firmly clamped to the pipe, never to come off ...

Valve back in place, compression nuts pinched up, olives appear to be clamped firmly to the 22 mm sides of the new reducers. Other ends of the reducers soldered to incoming and outgoing 15 mm pipes. Water back on.

AND THE BASTARD LEAKED. BOTH EFFIN' SIDES !!!!!

No amount of additional tightening, PTFE'ing, swearing at it or kicking of the cat that wandered past the back door, would improve it. So, with time marching on towards opening, I gave up, and fitted a piece of 15 mm pipe back into the gap, using those two couplers that I had fortuitously purchased ...

As both (very different) ways that I've tried to mount this thing have failed to work in the same way, and the fact that the low pressure side is actually worse than the high, the only conclusion that I can come to, is that the example that I have has been machined badly at the olive seats, or else the product overall, is a piece of shit. During over 40 years of DIY plumbing, I think I've seen most general problems of this type, and I don't ever remember one defeating me before. I'm not an expert by any means, but compression joints and adaptors, are hardly rocket science. I'm not sure what to do now. I was thinking that I might be able to get an O ring in between the olive and the seat, but I'm not sure that would be successful. Anyone got any suggestions, or can think of anything that I'm doing wrong, or missing. Incidentally, when it was in place, with the pressure gauge fitted, it did at least seem to be working, with a steady 3 bar output.

Arfa

[Roger Mills]

22mm fittings can often seem as if they are fully tight when they're not, because of the friction in the threads. If you disassemble your latest attempt, are the 22mm olives fully crimped onto the pipes?

Since you're now doing it 'off-line' so to speak, I would do the following: Smear some LS-X round the olives and round the threads. That on the olives will form a seal, that on the threads will lubricate. Hold the body of the valve in a vice and then do up the compression nuts with a half-way decent sized spanner. Wait an hour or so for the LS-X to go off and then re-install the whole assembly back into the 15mm pipe.

If *that* leaks, there's *got* to be something wrong with the valve.

[Dave Liquorice]

I support that idea, 22mm can be quite stiff unlubricated. I find that unlubricated finger tight, then half a turn with a spanner is a good starting point, if it "squeals" then it's probably sealed. Even so another quarter to half turn still might be required.

I do tend to put a smear of boss green over the olive and in the threads not as a sealent just as a lubricant.

Arfa is one of the more experienced DIYers in here, as indicated by the things he has tried and precautionary purchase of 15mm couplers. This does point to something up with the valve itself, are the 22mm olive brass or soft copper? Perhaps copper ones would make it seal?

[Arfa Daily]

Thanks Dave, and also to Roger for his suggestions. All appreciated. The first-tried 22 mm to 15 mm adaptor olives, are, I think, brass. I have to say that when I first looked at them, and decided that they were brass, I thought "Hmmmmm", figuring that they were going to take a lot of pulling down to get a good 'bite' on the pipe. The traditional olives that I tried for the second method of getting a fix, seemed to be soft copper, which is why I was particularly vexed when I didn't get a seal right off.

Looking back on it now I've had a chance to calm down, you could both well be right, and I have been too cautious in the tightening, mistaking the compression nuts tightening up from friction, for them being fully tight because they had done their job. Most of my experience with compression fittings, has for sure been on 15 mm, so I've maybe made myself a victim of my own inexperience with 22 mm, added to a natural caution of over-tightening.

Now it's all off where it can easily be worked on, I think that I am going to try again with my second method using the traditional copper reducers and olives, as well as lubrication and sealant, and stick an isolator valve temporarily on the end of the pipe tail on the outlet side. I'll then connect a hose from the outside tap, which has a lot of pressure, to the tail on the inlet side, and jube clip it on. I can then switch the tap on and close the isolator on the outlet side once there is water coming through. Hopefully, that should pressurise it enough to see if I've got a seal, before trying again at the 'real' installation.

Might be a day or two before I can try anything. My elder daughter has had to go to hospital tonight, and they've kept her in, so I don't know quite what time I'm going to have Sunday to 'play', and I am pretty busy next week with the 'day job'. I'll let you know how it goes. Thanks again for the advice lads.

Arfa

[John Rumm]

22mm can be difficult to get tight enough in some cases... a bit depends on the ease access and the size of the spanners etc[1].

I usually stick a few turns of PTFE on the threads to act as a lubricant, and stop it squeaking when tightened. It tends to make it easier to get the water tight joint with less physical force since more of the torque gets to actually rotating the joint rather than overcoming the friction.

[1] I remember having great difficulty tightening the nuts on the ends of some butterfly service valves in a CH pipe above a kitchen cabinet. There was probably only 6" of height between cabinet and ceiling, and that meant that longer spanners could not rotate enough to get the next flat into position, and short ones could not get enough torque in there easily!

Sorry to hear that. Hope she's well soon!

Let us know how it works out...

[Arfa Daily]

Thanks for your kind thoughts, John. Nothing too serious hopefully, so she should be out this afternoon.

All understood on the plumbing issues. The place where this valve is to be located, is not exactly 'tight' for space, but you are on a ladder as it is high up on the wall above a door, and a plastic waste pipe does run below it, which makes it a bit restrictive to get spanners on. I'm really beginning to think that not enough tightening is the issue now. I was holding the body of the valve still with an adjustable spanner, and tightening with full sized Moles, which I suppose might actually have been introducing additional friction problems from distorting the compression nut.

I have a chum who is a car man, and has every conceivable spanner type and size, known to man. He has volunteered to come and have a go (he's a proper DIY-er as well). I think that I am still going to go down the route of fitting 15 mm 'tails' to the valve using the B&Q copper reducers and conventional olives. When I did this originally, it actually looked a nice solution. It will also allow us to do the 'grunt' work on getting it to seal, off site using a vice etc. I can then fit it back in using a pair of

15 mm compression couplings, which will at least then make the job of patching the pipe up, just a case of two new olives and a length of pipe, should it have to come back out yet again ... :-)

Arfa

[Arfa Daily]

I've just had another 'outside the box' thought here. What about using a pair of tap connectors ? Those have the same thread, don't they ? I know that the flexible ones do in 15 mm versions, because I've used them to screw straight onto the tops of isolator valves. If I was able to do that, then the seal would be by rubber or fibre washer, straight onto the valve body, with no requirement to get an olive to seal onto the pipe, as well as into the seat in the valve body. Any thoughts ? Good idea ? Crap idea ? Not gonna work ? The area that would be sealed against is chrome plated, but looks ok. In so saying, the olive seat is also chrome plated, so not really any worse.

Arfa

[The Medway Handyman]

Best £7:50 I ever spent was on one of these

you have room to use it the welly you can use is amazing.

[Arfa Daily]

> If you have room to use it the welly you can use is amazing.

Noted, thanks.

Arfa

[Phil Addison]

>

I note you have cut an existing pipe to fit this to. Was the existing pipe possibly force fitted and under a bending force so that when you cut it, the two sides were not parallel? Sounds as if you'd have noticed this though, but if one end is not going in straight that could cause a failure to seal.

The difference between a dry and lubricated olive is amazing, as already pointed out.

You mentioned a fitting that is 'never to come off again'. Was that because the olives where well embedded in the pipe? If so a Dremel with a small cutting disk is how I get these off. Slice NEARLY through the olive so as not to cut into the pipe, then put a screwdriver in the resulting slot, twist and the olive snaps open.

Again something you no doubt checked, but was the pipe pushed right into the fitting? If the olive is too close to the end of the pipe it can leak.

Phil

[Arfa Daily]

It's a long run of pipe that I put in myself a few months back. When I made the cuts to take the short section out, there was no displacement of the pipe ends either side, at all.

This is my best feeling now, about why I didn't get a seal .... :-\

It's not an 'olive' in the traditional sense. It was the 22 mm to 15 mm adapting collar that comes with the PRV to allow it to be used on 15 mm pipe. It is an oddly profiled affair that's difficult to describe (I did try in the post that started the thread). The 15 mm pipe goes into this collar right up to a stop so has to be located in the right place by default. At the rear of this collar is a conical section that forms the piece that you would normally associate with being the 'olive', and it is this that has bitten down onto the pipe, "never to come off". I now have these two adaptors in my hand, and in actual fact, although they are never going to come off the little stubs of pipe that they now have left in them, without being cut off, if you try hard enough, you *can* just turn the pipe stub, which I think further reinforces everyone's suspicion that although the fitting had tightened to the point where it seemed to be as far as it would go, it actually wasn't ... quite ...

Thanks for your thoughts

Arfa