Black Plastic Water Main

[Ian10261]

Hello folks
Not been on here for a good while, been rather busy. To cut to the chase i came accross a black plastic water main sticking up into a stripped-our kitchen today and the kitchen fitter wants it moved back against the wall as opposed to the 14" off the wall it is now. In a nutshell has anyone encountered this type of pipe in 30mm O/D before coz i aint, 3/4" yes but not this one and if so is it possible to fit a stoptap directley to it or second best by adapting it to do so. At the moment it appears that someone has fitted a 22mm stoptap via what appears to be a short length of pipe literally stuck into the plastic. Guess you come accross summat new every day eh?

Cheers

"E"

 

[AWheating]

may get a fitting from bes, or get a transition coupler from plumbing merchants. The reason its not against the wall is for frost protection (750mm inside the building structure).

 

[Joncpi]

Sounds like it is some old 1" black plastic. Be careful this stuff is prone to splitting due to age. It was originally thought to last a very long time, but has been proved now sometimes to last less than 25years. All this pipe has now been superseded by MDPE. Is there any markings on the bit exposed? I think George Fischer do a brass fitting for this with a copper liner, to either 1" or 3/4" BSP. I don't want to be an old granny, but you have checked it is not actually 32mm PE? Do you know the approximate age of the pipe? Also look at water regs as the pipe is supposed to enter the property some distance in, 750mm from the outside skin, to be exact. So the kitchen fitter is asking you to move the pipe and contravene the regs.

 

[Guest123]

Alkathene was originally black but it was changed to blue because it was the same colour as electrical cable.

Adaptors are readily available.

 

[AWheating]

you can still buy some sized black mdpe for above ground work as the blue dont like the sun. bit like a british person on holiday.

 

[Ian10261]

Sounds like it is some old 1" black plastic. Be careful this stuff is prone to splitting due to age. It was originally thought to last a very long time, but has been proved now sometimes to last less than 25years. All this pipe has now been superseded by MDPE. Is there any markings on the bit exposed? I think George Fischer do a brass fitting for this with a copper liner, to either 1" or 3/4" BSP. I don't want to be an old granny, but you have checked it is not actually 32mm PE? Do you know the approximate age of the pipe? Also look at water regs as the pipe is supposed to enter the property some distance in, 750mm from the outside skin, to be exact. So the kitchen fitter is asking you to move the pipe and contravene the regs.

Thanks for the info, i measured it with an adjustable spanner and ruler and it defo came out at 30mm give or take a tiny fraction. I can get a universal type coupling that will convert it to 25mm or 32mm MDPE
but thats not really any good and besides the fitting is so big i'd be back to square one. I think i'm just going to leave it well alone and let the kitchen fitter have the problem of cutting around it.

 

[chris watkins]

Hi Ian
I would try the following -
http://www.philmac.co.uk/wp-content/uploads/3G_Met_Imp_Tech_Manual_V2_email_version.pdf

 

[Bernie2]

It may help to realise why it is 750mm. Frost penetrated the ground in the big 1963 freeze up to about 600mm freezing the incoming main water supplies. So they added on 150mm as a safety factor and made it 750mm. They also found it penetrated outside walls about the same, So they advise keeping it 750mm away from outside walls or insulating it so it does not freeze.

It may be black Alkathene which you can still get for above ground use, as blue MDPE is UV reactive. As I remember though there was quite a few Alkathene's around at the time all with a slightly different size. I think it was class "D" for underground. in reality you often came upon class C or E both low, medium or high density in various places it was crazy.

The type and size was usually stamped on the side of the pipe about every meter or so. But if you can't find it, as said I think they do make multi fit transference couplers that fit a few sizes of pipe.