MDPE to 15mm or Speedfit

[PeterC]

My neighbour bought a hose and reel so I landed the job of fastening it to the wall for her. The supply comes out through the wall in blue MDPE of about 15.3mm OD. It's just a bit big to go into the Speedfit Wall Plate Elbow that I have and a

15mm olive won't quite go on. Even if these would go on I'd need an insert and that'd push the OD up to about 16mm or so (I daren't try one in as I've about 10cm of pipe!).

Really, I'd like to plumb it properly but access inside is almost zilch and the pipe is ½", so it would be quite a job on it's own.

Now, looking on SF etc., I see mention of 20mm and 25mm MDPE, so what's this 15.3mm stuff?

There's some sort of tap inside (I can just see that it's the pipe-cutting sort) that she can operate but the gaps a bit small for my hand, so if necessary I can use a hose-hose adaptor on it :-(

Cheers.

[Tim Watts]

PeterC wibbled on Tuesday 06 July 2010 20:57

What you probably need for a pukka job is an MDPE-copper adaptor. I got one from BES for the next size MDPE up to yours, through to 22mm copper. I expect if you have a rummage that there is a 15mm version.

It's a bit of brass, insert, MDPE large olive and nut that does a compression fit to the blue. The other side needs to be soldered to a bit of

15mm pipe, to which you can plumb as required. The main thing about this type of adaptor is that it's very solid and the least bulky of all the types.

The next option might be to look at their universal adaptors - those are the bigh black lumps and convert most things to most things. I *think* speedfit is an option in one side - based on the way they work (grap spikes and a big fat doughnut washer) I don;t see why not...

[fred]

In article , PeterC writes

I think 15.3 is within tolerance for a 15mm nominal plastic pipe, you just need to try harder ;-). As you say you should use an insert for compression but it's only recommended for pushfit, not compulsory, so that would be the best bet.

Try putting a smooth 45deg chamfer on the end of the pipe to give it a bit of a lead in. For a good seal on the push fit O-ring, the pipe will need to be clear of longitudinal scratches. Compression would be more tolerant of scratches if there are any.

It's a bit weird to just have the bare end of pipe coming out of the wall, is it possibly a butchered install of something like this:

but with a 15mm pipe?

[PeterC]

OK, thanks. That looks like the 'proper' way to do it but as I don't have a torch (needed one about 15 years ago and borrowed it - not needed one since) it'll be the choice if all else fails.

[PeterC]

Even without an insert I can't get it in - although there's not really sufficient pipe to grip very well.

Yes, I cut a chamfer and used silicone grease and it still wouldn't bottom out. As for scratches, I can't do anything as it's already been bodged about (it had a hose coupling to female socket on it; I didn't realise until it blew apart due to the new hose not leaking!).

Yes, but just the bigger pipe. It did go down to a tap but was, for some 'reason', disconnected (her last BF is an electrician and I encountered his 'plumbing' when replacing the shower - also had to rewire!).

[fred]

Hmmn, you seem to have tried all the reasonable options.

Did you really mean 10cm of avail pipe? It sounds more like 10mm. If it's 10mm I think you're stuffed. If 10cm, can you grip the pipe at the wall with water pump pliers and push/turn for all you're worth with a pushfit fitting? (Bet you've tried that already).

Absolute bodge and last resort might be to try and reduce the diameter of the pipe by radial rubbing with wet & dry to get an olive to fit then chimp up a compression fitting to get bite on the pipe. Also wipe the pipe with liquid ptfe type pipe fitting sealant to seal any scratches on the pipe under the olive. I would still try to use an insert, I don't think the pipe will expand as much as you suggest.

[Chris J Dixon]

Where in the system is the mandatory check valve?

Chris

[dennis]

If you have a gas hob you can solder on the first bit of pipe using the hob and then use speedfit.

[dennis]

A lot of the self fit taps that self drill and come with "pipe" use washing machine hoses. Is it a piece of washing machine hose and not a proper pipe you have through the wall?

Can you see if its got a washing machine connector on the tap that you can unscrew and fit a new pipe?

The tap end would have had an insert and a clip, something like a jubilee clip and a brass push in fitting.

[PeterC]

Ah - somewhere, in a box, is a Camping Gaz stove :-) Plenty of solder (cored and plain) and flux. Bit of lead won't matter for a hose pipe.

[PeterC]

Didn't try gripping the pipe with a tool as I'm acutely aware that Plan B is limited and involves removing built-in kitchen units!

An insert, just in so that the first 'barb' is showing, increases the diameter to ~16.5mm; as the 15.3mm won't quite go in... Even a hose coupling won't go on, so that's out :-(

Actually, your suggestion of reducing the OD, whilst possibly making the surface too uneven for Speedfit, might well work for a hose coupling as that seals on the inside and only grips on the outside. I'll see how little needs to be done. Thanks.

[PeterC]

It'll be on the new tap, if I can get that far!

[PeterC]

Yes! Never though of that. It does have a sort of faint braided appearance. A spare w/m hose is 15mm OD. Thanks for that.

Needs a torch and possibly a mirror. I can't really get even 1 hand in there and she won't have the grip to do it. Even if I could get the unit out without wrcking anything, it'd be very disruptive in a busy household.

[Roger Mills]

Eh? Can't be the right insert for the pipe! Come to that, it can't be any of the usual sorts of plastic pipe if it's capable of being expanded that much by an insert.

[fred]

Agreed, it sounds way too floppy for MPDE, more like a washing machine or irrigation hose intended for use on barbed pipe fittings (LDPE).

Given that, it might be better for the o/p to mate the existing hose with barbed irrigation elbow (suitably braced with jubilee clip) which in turn could mated to something else. Pretty dubious for extended mains operation though.

Possible source:

[PeterC]

usual. It is washing machine hose (the 'braiding' pattern is rather worn/faded).

Managed to do a temp. lash-up with an old fitting from ~40 years ago that had a coiled spring as the clamp. Works quite well but isn't reliable, so I'll suggest a new tap set and hole through the wall in an accessiblr place (SDS here we come!).