Fiberglass vs. CPVC Pipe for Oxidizer Service

[RJB32482]

Hello,
I'm looking at using CPVC pipe for a drain on a heat exchanger that is used in a header for a thermal oxidizer. Currently we have used fiberglass for this drain. The condensibles could have very trace amounts of HCL (20 ppm at most). Temperature of the header at the most is roughly 45 degrees Celsius (highest temperature source on the header). The exchanger is for a booster fan for a pressure control loop. Of course as it cools the air, condensables collect in the tubes (its installed vertically) and needs to be drained periodically.

Does anyone have a sheet for CPVC piping vs. fiberglass to see if I can replace this drain with the CPVC pipe? Or direct me to a source? OR from experience if this would be sufficient?

Thanks.

 

[moltenmetal]

Depends on the size. I don't see a problem with you using CPVC for the service you describe, provided it's not pressurized beyond ~15 psig (sounds like it's almost ducting rather than piping from your description). CPVC, like PVC, has brittle fracture risk and shouldn't be used for pressurized gas piping- but ducting is fine. However, beyond about 4" NPS, you may find FRP piping to be less expensive than CPVC.

 

[RJB32482]

So for heat resistance and chemical compatability, the CPVC and fiberglass pipe are nearly the same? Or are there temperature differences?

Thanks for the reply.

 

[moltenmetal]

CPVC is limited to 80 C, and sags into a heap of goo at 100 C. You can push various FRP resin/reinforcement constructions to perhaps 130 C, but most are not used beyond about 105 C.

Chemical compatibility of the FRP depends on the resin/reinforcement chosen. Most are very acid resistant and completely chloride immune.