What size MDPE?

[hiccup]

Hi all

I'm in the middle of a major patio renewal project (160 sq m of paving) and am keen to get the right pipes in place for a future rainwater harvesting project.

All the downpipes will feed into one place where the Wisy filter will be positioned and then on to the tank.

But I also need to get some MDPE into the ground to connect the existing mains to the tank for top-up and then from the tank to the irrigation system and into the house for WC's and washing machine.

So am I OK with 20mm or should I use 25mm. I'm guessing the resistive losses are what counts.

(The existing mains is via 15mm copper.)

Hic!

[guydewdney]

as long as the runs are relativly short, and the mains pressure is OK - then 20 is fine - considering the incoming mains is 15mm.... mdpe fittings are bloomin' expensive.

[solar_cambridge]

25mm, but DO NOT use regular blue or black MDPE pipe for rainwater. Its against water regs and in the future when you've moved on some poor soul might see nice clean water and assume its ok to drink. I think the correct colour is green/orange coloured pipe which also has identification for recycled water on it.   

[guydewdney]

I Thought blue = potable, black = non potable - but I'm wrong - blue is below ground potable, black is above ground potable - but its often sold as non-potable!

Get some sticker saying not drinking water, and use black as its cheap, just wrap the ends in the tape....

[solar_cambridge]

I Thought blue = potable, black = non potable - but I'm wrong - blue is below ground potable, black is above ground potable - but its often sold as non-potable!

Get some sticker saying not drinking water, and use black as its cheap, just wrap the ends in the tape....

Something like this would probably meet the regs, but I def would try and find some pipe. I'm trying to find some mention of WRAS that stats the correct colour for the pipe.  Its a growing market so someone must be making it.
http://www.rainwaterharvesting.co.uk/proddetail.php?prod=RWH-ST01&cat=21
http://www.combinedharvesters.co.uk/productcart/pc/viewPrd.asp?idproduct=1140&IDCategory=8

[hiccup]

Thanks all

I'm going with black 20mm and will label it now and again as suggested.

Regards

Hic!

[Philip R]

Interesting one on the pipe colour code and the need to label it to show it is not carrying potable water.

Whilst on a recent plumbing course, one of the students, an expat in Kenya, produced a length of MDPE pipe from Polypipe in Kenya. It looked like seaside rock, colour coded correctly for rainwater.

I have been onto various polypipe websites to look for this product, but to no avail.

I will be following up with my expat friend and with polypipe to see if such a product exists in the UK or can be manufactured.

I can guess their response: No it is not ours, we will not make it.

In the meantime use the black MDPE with labels.