Main water supply pipe

[RussellS]

Hi everyone, I hope someone can help me,

I am in the process of refitting my downstairs cloakroom and wish to move the mains water stop tap that is in this room. The pipe coming into the house from the mains pipe outside is, I believe, black imperial 3/8 bore (approx 17mm OD diameter) Alkathene pipe. I need to extend this pipe so that I can put the stop tap in a more convenient place. I will obviously need to couple this pipe to 15mm pipe and I have seen suitable couplers in the YorkshireFittings catalogue, hovever I'm not sure about the inserts required. The catalogue mentions various different copper liners of different classes (class B red, class C blue & class D green) and was wondering what the differences are and, more importantly, which I should use and for what reason.

Also, does it matter what type of 15mm pipe I use to extend the existing pipe to stay within regulations. I was just going to use 15mm plastic pipe with comression fittings (NOT speedfit). Will this be ok.

Many thanks for any help and if anyone has any further suggestions I would be gratefull.


Best regards


Russell

 

[Slugbabydotcom]

Cant you just put another stoptap after the existing one. Best to avoid messing about with the pipe before the stoptap if possible.
If its not possible then I do believe that you are dealing with class C alkathene. It used to be black and since 1988 its blue in colour.
I know its not usually practical to dig it out to find out but there is usually some info on the details of the pipe printed on it.

If the rest of your system is copper then its best to use copper again for earthing purposes in this case.

 

[RussellS]

Thanks for the reply,

Unfortunately, the existing tap needs replacing and it is right down at floor level with only about 20mm of the black alkethene pipe above floor level. Also, the pipe comes up between a floor joist and the wall with only about 25mm gap and the pipe has a sharp bend below the joist to go through the solid wall. While the pipe may have been quite flexible when it was installed in 1964 I am afraid to bend it around too much now as it may be brittle. For this reason I wanted to cut it off further back where it is on a straight run under the floor and couple it to some new pipe and I can then place the new tap where I want it. The reason I wanted to use plastic pipe was because it is flexible and I would need to push it through under a floor that is inaccessible.

The existing black pipe has no markings on it at all from what I can see and I can get to about a three foot length of it under the floor but as stated earlier it is about 17mm OD diameter and is black.

Is there any special pipe I should be using because it is the supply pipe or would the normal white plastic pipe you get in B&Q or Screwfix be ok.

Any further advice on type of pipe used or what I'm doing in general would be gratefully received.


Many thanks

Russell

 

[Lagerkhan]

The pipe you have could be 17,18 or 20mm ? and i suggest you cut off a small piece and take it with you.
The inserts vary according to the pipe wall thickness so it is best to have it with you.
The fitting you will need will/could look something like this...this is a 20 x15mm push fit and if it was me i would use copper up to your new stop tap but that is up to you.

 

[RussellS]

Thanks for all your help. After looking around everywhere for the required fitting I eventually found one at Plumb Centre just half a mile from where I live. It's not like them one in your picture, it is a brass fitting but is specifically for my Alkethene pipe.


Russell