pinholes in hep2o plastic pipe

[dextrous]

Remember reading in some Hep literature along time ago that pipe was not suitable for secondary return applications. Something to do with not being able to withstand very high temperatures for very long periods of time, 24 hours a day in this case. Maybe wrong, worth checking though. On a different note, a friend of mine had a couple of Polytpipe fittings blow off. Polyplumb technical told him that their systems should be tested to EIGHTEEN bar. How many of us do that? Seems that the guarentee is totally worthless if that is the case.

I'm enjoying this

 

[mickyg]

I wouldn't consider the temp of dhw generally "very high"

 

[avidfan]

http://www.hep2o.co.uk/v2Onottouse1.htm

Refer to secondary circuit as 'Ring main', but there you have it in black and white.

 

[doitall]

Remember reading in some Hep literature along time ago that pipe was not suitable for secondary return applications. Something to do with not being able to withstand very high temperatures for very long periods of time, 24 hours a day in this case. Maybe wrong, worth checking though. On a different note, a friend of mine had a couple of Polytpipe fittings blow off. Polyplumb technical told him that their systems should be tested to EIGHTEEN bar. How many of us do that? Seems that the guarentee is totally worthless if that is the case.

Not a lot to do with high temperature, but constant temperature.

Plastic pipe looses it's properties and needs a cooling period every 24hr period to regain its factory condition.

Continuous 24hr operation is a big No No, and that is why they say its unsuitable for secondary circuit, the same would apply if it were a heating system, running 24/7.

 

[Onetap]

Not a lot to do with high temperature, but constant temperature.

Plastic pipe looses it's properties and needs a cooling period every 24hr period to regain its factory condition.

Continuous 24hr operation is a big No No, and that is why they say its unsuitable for secondary circuit, the same would apply if it were a heating system, running 24/7.

I hadn't heard of that before.

I've never heard of a DHW secondary water circulation system called a ringmain before either.
I looked at the Speedfit Installation guide and it has almost the exact same wording. The constant temperature explanation can't be entirely correct, since plastic pipe is used for UFH which often does operate 24 hours a day. Is it something to do with hot & chlorinated water?

 

[doitall]

Underfloor heating is a different pipe.

We had a very difficult job at a nursing home, and a 100m coil of 22mm pipe would have been ideal to thread through the building as a secondary circuit.

Hep Technical would not advise running their pipe 24/7 at 62c as the pipe needs to recover.

Whether that has changed over the last couple of years I don't know.

 

[Onetap]

Underfloor heating is a different pipe.

I don't think it is a different pipe. HEP2O is polybutylene (I think) Speedfit is PEX, both are used for UFH. There's no major difference, except maybe an oxygen barrier.

 

[doitall]

Underfloor heating is a different pipe.

I don't think it is a different pipe. HEP2O is polybutylene (I think) Speedfit is PEX, both are used for UFH. There's no major difference, except maybe an oxygen barrier.

Speedfit make Pex barrier pipe and Polybutylene barrier pipe, the later for underfloor heating.

 

[muggles]

Remember reading in some Hep literature along time ago that pipe was not suitable for secondary return applications. Something to do with not being able to withstand very high temperatures for very long periods of time, 24 hours a day in this case. Maybe wrong, worth checking though. On a different note, a friend of mine had a couple of Polytpipe fittings blow off. Polyplumb technical told him that their systems should be tested to EIGHTEEN bar. How many of us do that? Seems that the guarentee is totally worthless if that is the case.

Same with Hep2o http://www.hep2o.co.uk/v2Otesting1.htm

They measure the depth of the grooves in the pipe where the grab rings are to ensure testing has been completed properly.