CPVC for a hot water heating system?

[carlosgw]

Have you used CPVC piping for a baseboard or fintube hot water heating system? (design temperature of say 170 deg)

 

[dbill74]

No, and I would not.
CPVC is generally only rated to 180°F. Having a constant 170°F is just too close to the limit for my comfort. IMO, too much risk of pipe failing.

 

[RossABQ]

Good succinct "rules" for CPVC here:

http://www.harvel.com/piping-systems/gf-harvel-cpvc-industrial-pipe/temperature-derating

30% of nominal pressure ratings at 170F, no glued joints over 150F, etc. Imagine a failure with 170F water... That could be really ugly in an occupied space.

 

[rconner]

[fyi while I certainly share the others opinions/unease of mixing plastic pipes and hot water, if you read the linked article closely I believe you will see that "solvent cemented" (aka' "glued") joints are actually promoted at the higher or "maximum" temperatures. (This probably means other joining means are in general even more risky business.)]

 

[lukaiENG]

The expansion of the pipe would be a nightmare as well. steer clear!

 

[317069]

Check the CPVC product literature, discuss your question with the manufacturer if his product is certified to serve a hydronic heating system.
From Wikipedia, the melting temperature of CPVC is about 395(not F), and vacate softening point is more than 106C(222F)
in Europe and middle east they widely use nonmetallic piping for hydronic heating systems but I am not sure if CPVC pipe is one of them. If the CPVC expansion is a nightmare, what about cooper pipes or the baseboard itself.?

 

[rconner]

The website at

http://www.engineeringtoolbox.com/thermal-expansion-pvc-d_782.html

indicates cpvc has even more thermal expansion than regular pvc pipe, and I believe the latter has more than three times the expansion or contraction of copper (for the same delta T's).

 

[lukaiENG]

The pipes used in the UK and Europe have better properties than PVC & cPVC. Here is a product I am familiar with, it is not by any means the only one available.

http://www.aquatherm.com/

I believe pipework expansion is still higher than copper, but it is better than PVC.

 

[collosus]

Your talking about PEX Tubing I believe. Theres a type called PEX-AL-PEX which comes with an aluminum lining. It is specifically designed for heating applications. Take a look at this thing.

http://www.canarsee.com/pex/pipe/1-2-in-x-300-ft-pex-al-pex-tubing?___SID=U