PVC and CPVC boiler piping

MICHAEL HAERTSCH

I RECENTLY SAW A MUNCHKIN BOILER PIPED 100% WITH PVC AND CPVC. THE BOILER SUPPLIES HEAT TO A RADIANT MIXING VALVE AND 5 FAN COILS. WHAT DAMAGE WILL BE DONE TO THE TACO CAST IRON CIRCULATORS OR THE BOILER? AS FAR AS I KNOW NEITHER MATERIAL WILL PREVENT OXYGEN DIFFUSION. WILL THE STAINLESS SCALE UP OR FOUL?

John_82

I would have to imagine any ferrous metals in the system would oxydize. not too good.....

Brad White_46

PVC/CPVC

PVC has a maximum temperature rating of 140F and CPVC higher, approaching if not over 200F. The ratings are dependent on pipe size, coincident temperature and coincident pressure.

Both would seem to fall in line with a really low temperature hydronic radiant application. I use CPVC for pool heating sections when using a PoolPak or similar pool water cooled dehumidifier.

The coefficients of expansion are higher and support spacing would be greater. The material was often used in developer-based water source heat pump systems in the 1980's. First-cost motivated.

I cannot speak to O2 diffusion and cannot think of any damage that can be done short of shavings and other debris which should be cleaned out of any piping system anyway.

On the whole though, I would have to as, "why?"

Just seems too "cheap" for some reason. May work technically (except for the O2 diffusion issue perhaps) but I just like metal that I can push against if I so choose.

My $0.02

Brad