Hello,

I am at the water works plumbing stage and need to run a few lengths of 32mm tubing to accomodate my cooling requirements. After a quick visit to B&Q I now know that plastic plumbing pipe is cheap at that diameter. However, I was wondering if that would be suitable for use in a 7 before I buy it. Any ideas?

Plastic softens with heat. Car coolant is hotter than domestic hot water or central heating. Can you not get copper plumbing pipe at a reasonable diameter?

We've used some plastic push fit pipe on ours and its held up ok full of water for the last 6 months and done about 200 miles some of which were very hot as we were trying to tune the engine.

We used it to get under the steering column to the lowest rad connection, Rather than crushing a hose we decided to warm and then squash the plastic pipe in the hope that it would retain its volume and flow well.

as above soil pipe is only able to take hot temps for short times like pouring out hot water from the pan not for extended use. plus prob look nasty i say remove the cobwebbs out the wallet

AFAIK, the highest spec'd plastic pipe available for domestic central heating applications is cross-linked polyethylene (PEX) but like Smart51 says, the coolant temperature at times will far exceed the maximum designed limit for this type of pipe.

Stick with copper or aluminium tubing for the coolant plumbing.

Phil

28mm copper with solder ring fittings on the end is about as near as you could ask to get to 32mm with a bead.

tom

After witnessing what a failed heater pipe did to Hicost's leg at donnington, I urge you not to take any safety risks with the water plumbing.

It's right up there on my list of "things not to do wrong" along with brakes, propshaft and lightened flywheels.

I've used the stuff labelled as 'high temperature' plastic 32mm pipe on my radiator return.

It doesn't go soft and worked absolutely fine on my CVH.



Stu

Stu

[Edited on 3/3/08 by whitestu]

[Edited on 3/3/08 by whitestu]

Much like the OP I have concidered using 32mm plastic pipe as its easy to get hold of compared to metal alternatives. Where have people found copper or alu 32mm pipe? I am especially after a 32mm 90 deg elbow peice.
I guess I could use 28mm gas pipe, which is easily sourced and flare the ends manually again but dont like the idea of yet more flow restrictions.
Sorry for a little hijack OP but it was my guess a supplier would be of use to you too.

Straight 32mm OD aluminium tube is £10 per meter from CBS
http://www.cbsonline.co.uk/aluminium-tube-262-c.asp

32mm ID elbow in siliconne is £8.89 from RallyDesign.
http://www.rallydesign.co.uk/product_info.php?products_id=3696

Merlin also do alli tube and will bend if for you.
http://www.merlinmotorsport.co.uk/SHEETS-AND-TUBING/c321/index.html

Good links chaps, just the stuff.

Yep, I'm sold too. Thanks.