randall977 Apr 30, 2012 5:03 pm
Subject: Heater pipes...

I'm trying to source new water heater pipe (the ones which run under the car to the rear heater). LDPE pipe, the type used in irrigation systems, is identical in size and look but...

'For common commercial grades of medium- and high-density (M/HDPE) polyethylene the melting point is typically in the range 120 to 130 °C (248 to 266 °F). The melting point for average, commercial, low-density polyethylene (LDPE) is typically 105 to 115 °C (221 to 239 °F).'

I think they would have used something readily available and LDPE would have been, plus it can easily be thermally set to a metal pipe joint... My original pipework has sagged between the retaining clips showing that it has obviously distorted so it suggests LDPE?

Any ideas greatfully recieved!

David Apr 30, 2012 6:13 pm
Subject: Re: Heater pipes...

Hi Christian, I'd have thought pipe designed to carry hot water rather than cold would be a better option?

randall977 Apr 30, 2012 10:45 pm
Subject: Re: Heater pipes...

Tested a sample upto 125 degrees and it only got very slightly softer...so must be HDPE or simular. Shame as LDPE looks perfect, getting hold of small bore non rubber black pipe is difficult

alecrb May 01, 2012 1:11 am
Subject: Re: Heater pipes...

You can quickly check to see if the pipe is polyethylene or polypropylene by seeing if a piece will float in water. These are the only two common plastics that will. ABS and PVC can handle a bit higher temperatures (and can be solvent-bonded, unlike PE and PP). If you can find CPVC, that would be the best.
Alec

randall977 May 01, 2012 8:26 am
Subject: Re: Heater pipes...

Thank you Alec for that helpful advice. It doesn't float...

randall977 May 02, 2012 11:23 am
Subject: Re: Heater pipes...

Pipe is Nylon semi-flexible 5/8 o.d. available from a few places, has various industrial uses.

randall977 Nov 29, 2012 10:27 am
Subject: Re: Heater pipes...

The pipes required for the fuel line and heater pipes are as follows;

Fuel Line - ID 5/16" OD 3/5" Black Nylon
Rear Heater Pipes - ID 1/2" OD 5/8" Black Nylon

If you want to know where to obtain these get in contact.