On Thursday 30 January 2014 10:08 RJH wrote in uk.d-i-y:
Either run hot water through it or bend it backwards...
JG Speedfit have a "new" pipe called "Layflat". It does handle pretty well (I used it for underfloor heating).
It is polybutylene (PB) rather than PEX, so I'm not sure if that's good or bad logevity wise...
On Thursday 30 January 2014 10:05 RJH wrote in uk.d-i-y:
I had a couple of short drops of copper for my machines, supported 1.5ft upwards. They were fine, until I replaced my dishwasher with a Miele with one of those big heavy auto-shutoff valves on the hose end.
I added a brass munsen clip[1] just behind the isolator. I'll do the same on the washing machine drop later.
[1] Because a) The screw holes are either side of the pipe so retrofitting is possible; b) They are adjustable for pipe-wall distance.
My parents CH was put in with a plastic microbore system 40 years ago - various sizes from 6mm OD to 12mm OD, pre-calculated, so no balancing required. It lasted a little under 30 years before becoming so brittle that knocking them while vaccing or trying to move them a few inches to reach other pipes behind caused them to snap. Over a period of a couple of years, every single piece had to be replaced; which was done with copper.
Hopefully the stuff on sale now will be longer lasting.
SteveW
Not CH but a while ago I stayed at a guest house with en suite facilites. After I'd used the sink in the morning the water draining from the sink slowed to a crawl - I realised that somewhere along the line the pipework was in plastic and unsupported and the hot/warm water going to waste was causing it to distort.
Yes, I also used brass compression fittings on MDPE, but they are specially made for MDPE as pipe sizes are different from copper. At one end it was an adapter to a 22mm brass stub (which I soldered to a 22mm end-feed fitting, before attaching the MDPE;-), and the other end was a brass compression MDPE to 7lb lead adapter.
I also bought equivalent plastic fittings in case there was a problem with one or other type after I'd gone past the point of no return sawing off the old lead main, but I used the brass compression fittings to reduce usage of limtied life O-rings. (There's an O-ring in the lead connecter, sort of in place of an olive, but it's clamped tight onto the pipe, unlike push-fit O-rings).
If you don't need runs longer than 3m, you can buy straight 3m lengths. However, make sure you store it straight, or it will take on a curve;-) Note that it will sag in use (particularly with hot water) unless you use plenty of pipe supports.
On Thursday 30 January 2014 17:15 Andrew Gabriel wrote in uk.d-i-y:
Indeed - it was quite a large olive. I liked the confidence as it is inside the house where the main enters the stopcock.
Sounds like what I used to make the transition to copper.
I used the universal adaptor for MDPE to 1/2" alkathene (my main) but as was in a hole in the ground, it worried me less. I did turn off the main at the road and pressure test it to 10 bar - it held!
But you're right - those big MDPE joints do clamp down very well.
Yeah. And when they blow, they blow catastrophically and without warning after as little as 10 years whereas with copper, any leaks are rare and typically just drip, drip, drip. Plastic fitting may be ok - *may* be - if they're fitted properly by someone who knows what they're doing and doesn't cut corners, but there are too many wankers around for my liking. I'll stick with copper.
Oh bugger. I just said exactly the same thing before reading your comment!
Istr that inserts are sposed to be used on all placcy pipe fittings? Incl placcy on placcy.
Jim K
I found a similar aerosol coming from a copper pipe in my parents house. That pipe was about 22 years old, so the 28 yo plastic I have used is better from the limited samples.
Yes generally. Speedfit certainly recommend it.
Yup Hep2O too.
Jim K
Yes and you need the correct one for the pipe. A professional I saw doing some work was fitting the wrong ones and said they were universal when I asked why. They were really sloppy and would not have stopped the pipe deforming.
How often do they blow in such a way after such a time? They might leak, due to failure of the o ring seal (though none have in my direct experience) but if the oint is going to come apart it normally does it pretty soon after being made, normally because the pipe isn't properly inserted.
it's the drop, drop leaks that have caused me the problems here.
I'm doing my plumbing, what happens somewhere else isn't of that much concern to me.
But there is no may about it, a properly made plastic pushfit joint is absolutely fine - and that isn't difficult (though like anything else, bodgers will mess it up)
Not that I'm flag carrying for any particular sort of plumbing, I'll use copper, plastic, pushfit, solder, compression depedning on what suits best.
Most of which seemed to have been due to incorrect jointing. Anyone mentioned hacksaws yet?
Most plastic tube will probably outlive all of us.
PEX is good for any where copper tube is liable to be stolen and external stuff; it freezes, but generally stretches and doesn't split. It's crap for any exposed pipes.
I prefer copper, but it costs more, the main reason for the rise of plastic.
My personal bitter experience says otherwise. I had one of these joints blow out and flood my utility room before I could reach the main stopcock and turn it off; it happened that fast. On examination, there appeared to be nothing whatever wrong with the joint! The O ring and the other components were in *perfect* condition and looked like it could have been assembled yesterday (rather than 2 years ago which was the case). I can only guess as to why it decided to suddenly 'let go' so violently, but I do believe the failure arose from my having moved the pipe to one side a couple of times to get access to the wall behind it. Seems this joint was fine all the time it was undisturbed, but couldn't handle temporary re-orientation once it had 'settled in' as it were. It was a lesson, I reckon. I quickly replaced all the plastic unions with proper copper ones. I couldn't sleep at night with the thought of that happening again!
Grab ring wrong way round.
Jim K
little teeth marks left on the pipe suggest that was not the case.
Unless made when pipe inserted (with grab ring reversed)...
Else how do you explain this anomaly then? Seems rather rare unless user error....
Jim K
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