Brass stop cock and MDPE pipe

[Forster1993]

Hello,

I am relaying my water pipe to replace the old lead one and I'm also relocating the stop tap in the process.

I have laid my MDPE in a trench and fitted an INSUduct. The MDPE then comes into the house into a brass stop cock with the intention of fitting 22mm copper to the other side.

Now the problem is after I torqued up the compression fitting on the stop tap, the pipe won't pull out of the stop cock but it does spin. Will this cause a problem?

Thanks

 

[BigSnoopy01]

if its compression and spinning the its not going to hold wata.

 

[Forster1993]

Okay I will have to get another stop cock this is the one I have?

http://m.screwfix.com/p/poly-stop-cock-22-x-25mm/97324

Will this style work with MDPE pipe?

 

[Newboy]

It should be OK but there are two reviews on the Screwfix site - the first has exactly the same problem as you

 

[Newboy]

Quick thought - did you use an insert in the MDPE?

 

[Forster1993]

Yes I did use an insert

 

[Newboy]

Sounds like poor product tolerances then

 

[Jackrae]

OD of MDPE is not the same as copper - you need a valve designed to connect to MDPE OD is typically 20 or 25mm as against 18 and 22 for copper

Get an MDPE stop valve and an MDPE to Cu convertor coupling

 

[Forster1993]

That fitting is designed for MDPE.

However the OD is the OD regardless of material, I don't think you can get 25mm copper so a 25mm fitting is pretty much always for MDPE

 

[Echo the husky]

It should be OK but there are two reviews on the Screwfix site - the first has exactly the same problem as you

I fitted one of those from Screwfix here about 8 months ago and it has been fine, the bad reviews were there at the time but I took a chance. Perhaps there was a bad batch.

 

[Forster1993]

It should be OK but there are two reviews on the Screwfix site - the first has exactly the same problem as you

I fitted one of those from Screwfix here about 8 months ago and it has been fine, the bad reviews were there at the time but I took a chance. Perhaps there was a bad batch.

Did you know if yours spun in the fitting?

 

[Echo the husky]

I don't think so, I did the MDPE part first then restored the water before fitting the copper. If it was loose I'm sure I would have noticed.

 

[Forster1993]

It's not loose as such, it doesn't wobble in the fitting just if I grab it I can twist it

 

[Madrab]

Have you made the pipe live? Does it actually leak? Some MDPE fittings can move once they're fully engaged but they have sealing rings that are rubber and plastic and can move without leaking.

Is it fully nipped up? Sounds like it might need that extra 1/4 turn. Is it a brass or copper olive?

 

[Forster1993]

It's not live yet no, severn Trent inspected and approved today so will be in the next two weeks. The fitting is brass the olive is copper