Best plastic to use for potable hot water

[quizzical1]

Hi All,

Can anyone recommend a plastic or range of plastics for use as a potable water commercial plumbing valve body / internals that can accept the stress of NPT connections and water pressures up to 200F @ 150 psig?

We were considering PVC, CPVC, PE, PEX, PE-RT, PP, SP, ABS, and 30% Glass-filled Noryl but was hoping you guys could be able to help us hone in on one - or a better one not listed - which could be injection molded easily.

TIA,

~Q

 

[TugboatEng]

Diameter matters.

https://www.corzan.com/en-us/specification/pressure-ratings

However, I don't think you're going to find any plastic that will work reliably at those temperatures and pressures while also using NPT threads. The tapered threads have a wedging effect that elevates the stress into the the creep region. Glass reinforcement will help. If you're working with dissimilar materials, high coefficient of thermal expansion of plastic is also a challenge for NPT connections.

 

[PEDARRIN2]

Other questions are why such a high temp and pressure for a domestic hot water system? Hospitals don't even take them that high when disinfecting.

 

[quizzical1]

Sorry guys, some clarification:

Tug - largest size would be 1" NPT (thanks for the link)

Pedarrin2 - nominal temp ~140F and 180F for disinfection. Or the use of chemical (Chlorine Dioxide)

Working pressures would typically be 50 - 80 psig but am concerned about structural integrity (hence the glass filled option)of the valve assembly in a pipe run.