Which 25mm MDPE fittings?

[-rick-]

My flat is fed from a 32mm OD (25mm ID???) MDPE pipe. Today the water maintenance company were here to disinfect the tank on the roof and as part of that isolated the supply. When the supply came back on the right angle MDPE fitting in my ceiling started letting a lot of water out of it.

 

Seems like the fitting loses its seal when the pressure is off and then is at risk of blowing off the pipe when the pressure comes back. Managed to isolate at the meter and with extra hands reintroduced pressure while holding the fitting in place and now pressure is back on with no leaks.

 

However, my confidence in these fittings is now shot and I want to replace them. I assume I need to get compression type fittings.

 

Should I favour any specific brand? Any gotchas I should look out for?

 

 

[Nickfromwales]

There’s no way that should have pulled / blown off, unless it wasn’t seated fully into the fitting (Plasson?) properly.

 

Don’t choose compression onto MDPE as that’s garbage compared to a proper MDPE fitting + insert.

 

If you’re not sure, replace like for like, and mark on the blue pipe the depth of the fitting to the internal stop point (like a shelf that the pipe insert butts up against and then can’t go in any further) so you know the pipe is fully ‘home’ in the fitting.

 

I’d say it was poorly installed or being not fully home that caused this. 

[ProDave]

Check it has the proper insert into the end of the pipe.  Often missed out.

 

 

[-rick-]

51 minutes ago, Nickfromwales said:

There’s no way that should have pulled / blown off, unless it wasn’t seated fully into the fitting (Plasson?) properly.

 

Certainly once the pressure was off and I felt the pipe it was possible to push the fittings on by another inch with zero resistance. Pipe was completely free to move. When the pressure was turned back it pushed the fitting back out with some force as I was trying to hold it tight. Shouldn't the joint seem stiff/tight even with no pressure?

 

Just had a look on the Plasson site, nothing that matches these fittings on there (at first glance).

 

51 minutes ago, Nickfromwales said:

Don’t choose compression onto MDPE as that’s garbage compared to a proper MDPE fitting + insert.

 

I meant compression MDPE like this, in case that wasn't clear: 

https://www.pipestock.com/mdpe/mdpe-pipe-fittings/mdpe-elbow-90

[-rick-]

Looks like the existing are Talbot:

 

https://www.plumbingforless.co.uk/plumbing/atplas-talbot-mdpe-fittings/talbot-elbows/talbot-pushfit-90-degree-elbow-32mm-e2784

[-rick-]

FWIW these fittings are approx 20 years old. Google suggests a known failure of them is o-rings failing due to age (15-20 years).

[Nickfromwales]

5 minutes ago, -rick- said:

 

Certainly once the pressure was off and I felt the pipe it was possible to push the fittings on by another inch with zero resistance. Pipe was completely free to move. When the pressure was turned back it pushed the fitting back out with some force as I was trying to hold it tight. Shouldn't the joint seem stiff/tight even with no pressure?

 

Just had a look on the Plasson site, nothing that matches these fittings on there (at first glance).

 

 

I meant compression MDPE like this, in case that wasn't clear: 

https://www.pipestock.com/mdpe/mdpe-pipe-fittings/mdpe-elbow-90

Ah! Gotcha. Yes, that type of fitting is also robust.

 

Being able to push the pipe an inch means it wasn’t past the o ring, so you were living on luck there!!

 

 

yup. Just found the bugger lol. 

[Nickfromwales]

Just now, -rick- said:

FWIW these fittings are approx 20 years old. Google suggests a known failure of them is o-rings failing due to age (15-20 years).

I know the feeling. Some of my seals are less robust these days   

 

Sounds like an issue to put back on the leaseholder? Or have you signed your life away? 

[-rick-]

Just now, Nickfromwales said:

I know the feeling. Some of my seals are less robust these days   

 

😆

 

Just now, Nickfromwales said:

Sounds like an issue to put back on the leaseholder? Or have you signed your life away? 

 

I am the leaseholder. Would dearly like not to be but stuck here until the cladding issue on this building is fixed (even then flats in London are not in high demand right now so I'm likely stuck here for a while).

 

So what should I do? This is the second time this fitting has leaked after tank maintenance. Trust it, despite it being very loose (even after pushing back on as best I could with the access)? Replace with same fitting? Or something else?

[Nickfromwales]

31 minutes ago, -rick- said:

 

😆

 

 

I am the leaseholder. Would dearly like not to be but stuck here until the cladding issue on this building is fixed (even then flats in London are not in high demand right now so I'm likely stuck here for a while).

 

So what should I do? This is the second time this fitting has leaked after tank maintenance. Trust it, despite it being very loose (even after pushing back on as best I could with the access)? Replace with same fitting? Or something else?

Replace with new, I’d go Plasson. 

Edited 2 hours ago by Nickfromwales
My phone is dyslexic

[ProDave]

I would replace with this. https://www.screwfix.com/p/floplast-492015-mdpe-elbow-25mm-x-25mm/14096

 

Part of the locking mechanism when you tighten the compression bit is they physically dig into the pipe so there is no way they will pull out without dismantling the fitting.  You First push the pipe into the fitting and you can check it has pushed properly into the O ring seal only then do you tighten the compression bit which ensures it is not coming out, pressure or no pressure.

 

All my mdpe pipe is connected with that type of fitting.

[Alan Ambrose]

>>> Should I favour any specific brand?

 

+1 Plasson

[-rick-]

Right so Plasson it is.

 

Plasson Compression or Push fit?

 

For the elbow:

 

https://www.pipestock.com/plasson/pushfit-fittings/plpf-elbow-90 (350107 - 32mm push-fit)

https://www.pipestock.com/plasson/compression-fittings/plmf-elbow-90 (352354 - 32mm compression)

 

For the copper connection:

 

https://www.pipestock.com/plasson/pushfit-fittings/coupling-pe-x-copper (350068 - 32mm to 28mm push fit)

https://www.pipestock.com/plasson/compression-fittings/adaptor-male-bsp (352288 - 32mm to 1 1/4"/28mm compression)

 

Plus 32mm pipe liners x 3:

 

https://www.pipestock.com/pipe-liners

 

The order process recommended a Boa Strap Wrench as well for the compression fittings.

 

This will be my first time doing something like this so a few more questions:

 

1. Will I need to/should I be prepared to trim the ends off these MDPE pipes to get a good end?

2. If so, I assume I need pipe cutters. Deburring tool? Probably try and find a short length of pipe as well as a straight connector as there isn't much slack anywhere.

3. If using compression to the copper side, do I need PTFE/thread sealant? New olive?

4. If using push-fit, should I plan to cut the pipe and make a new fresh end? So pipe cutters and wire wool?

5. No pipe liner required for the copper end if using push-fit, right?

5. Anything else I'm not thinking of?