15mm pushfit problem

[borzio]

Hi guys, I've been replacing a sink and worktop and have a problem with the plumbing, the hot and cold feeds come from grey 15mm PB Barrier pipe connected to two stopcocks.

I had to cut the two PB pipes to fit with the different layout of the sink from the original. I've been to Toolstation and bought from their PB Barrier pipe page some elbows, extra grab rings , spacers, pipe inserts and 'o' rings as I live quite far out of town.
I've put the elbows on the cut PB pipe with an insert, pushed in, pulled back to check they are secure and tightened the connector end with a wrench. One PB was going to a 15mm copper tail, the other to grey PB and to a straight connector. I checked the assembly of the fittings before use and they all have grab ring first, teeth facing the body of the connector, spacer, 'o' ring, then the connector screwed end. I mounted them all this way.
They have all blown off the pipe, so obviously I'm doing something wrong. The first time, and first joint blew off with very little pressure in the pipe, actually it was only the build up from the stop cock which allows a small amount past when fully off. I was left with the pipe insert in the fitting and the rest on the pipe. It appeared the grab ring hadn't grabbed.
Separately, a fitting blew off the copper when a bit of mains pressure was applied. Another fitting blew off similar to the first.
As an occasional amateur at this game, the plastic pipe inserts seem loose compared to when I originally used metal ones a few years ago. The PB is fairly old, but in good nick, left over from when we did the house 7 years ago.
I'd appreciate your advice, (call a plumber is a good call but hard to get rurally), and I can't see why these connections should be difficult at all

 

[dreadnoughtheating]

questions, questions, questions.

usually along the length of the grey pipe there will be a name and some details of what the pipe is made of, suggest you take a close look and report back?

Secondly, please inform me/us (?) of the brand name of the fittings you have bought?

Extra grab rings?, why? please do not say the elbows etc that you have bought do no have any? Secondly, did you insert the pipe, with insert, right up to the 'inside' endstop inside the fitting?

It is crucial that the correct insert is used for the pipe. e.g. John Guest (speed fit) for their pipe, Hep2o for their pipe etc.

photo's oh, how we love photo's. Some of those would be helpful.

DH

Oh, and to find a reputable 'Registered Plumber' in your postcode area, take a look at CIPHE.org website 'find a plumber', we all have to abide by codes of practice to be entered on that register.... its nothing like rated-people, checkatrade et al.

 

[borzio]

Hi Dreadnoughtheating, thanks for the reply
I've checked the pipe..Hep2O 15mm Barrier Central Heating
The fittings aren't brand named but have 2006 Class S 15mm PB and are from Toolstation as are grabs, inserts etc.
Extra grab rings etc ? Just for my store in case I reuse the fitting in the future, as I read you shouldn't use the grabs twice. Not for this job.
Yes, I did insert all the way.

I didn't know the pipe was Hep2o (should have looked would have saved much grief) before I went to Toolstation, so from what you have said above, I guess at least the insert is wrong, and probably the elbows as well?

Thanks also for the tip for CIPHE.org, it's appreciated

 

[SandyLyon]

Just had a look on Toolstation site and the Grey Pushfit fittings look like PolyPlumb or PipeLife.

These are an "O" ring first type of fitting that means that the pipe passes through the "O" ring first before passing through the grab ring.

Therefore it's imperative that the pipe is pushed into the socket fully otherwise the teeth will not grip the pipe.

Are you sure the pipe was pushed in fully, you can sometimes tell by looking at the pipe to determine where the teeth have been

 

[borzio]

Hi Sandylyon, thanks, they came assembled, and after the problem of them detaching I checked a spare fitting of the same type to make sure I had them installed correctly. As you say, the pipe goes thru the end of the fitting into the 'O' ring, then into the spacer, then the grab ring, then into the socket of the elbow fitting. I'm sure they were pushed as far as they could go, which I presumed was into the socket. (I've never had a problem seating these in the past). I pulled back to make sure they were secure. When they blew out under pressure, several of them didn't show any indent from the grab rings. I took one fitting that did work correctly apart again to see what the difference was and it was solid with the grab ring immovable and where I would expect it to be on the pipe if it had seated in the socket properly.
I'll get Hep2O elbows and inserts tomorrow and swap them over, unless you can advise that the Hep2O inserts will work inside the Polyplumb fitting.

 

[polesapart]

You match the inserts to the pipe. Pipe manufacturers own inserts only, ever. (ID varies.)

Pipe OD is standard , you can normally get away with using another manu's fittings although not recommended. OK where accessible as in your case IMO.

Pipe must be cleanly cut, unscratched. Messing about with/ disassembling/reusing fittings can cause more problems than they are worth.

I personally like a light smear of silicone grease on the pipe to aid full insertion, but hey that's just aging for you .

 

[borzio]

Thanks polesapart, you're right on all counts. I bought the Hep2o elbows today, took the polyfit ones off, put Hep inserts in, pipe all the way in.... and voila! problem solved! I was talking to a plumber at the store and he said the same thing as you about the problems caused by assembly/dissassembly....he also wasn't that enamoured with Polyfit connectors, saying he had come across more problems with them than any other connector....he wouldn't use them, but that was just his opinion for what it was worth.
So thanks all for the help and advice....great job.