Bypass Valve On Heater

[mas985]

Here are one set of pressure deratings for both PVC and CPVC. 2" schedule 40 PVC has a rating of 200 PSI at 110 deg F which much more than what is needed for a typical pool system.

It is true that PVC is more easily deformed at higher temperatures but according to this reference, PVC really doesn't start to significantly soften until 54 degrees C or 129 degrees F and that is with a lot of loading. The derating for pressure drops much sooner but the rigidity isn't affected as quickly unless of course there is a large load on the pipe but given the short sections of pipe, it is unlikely that the pipe would ever sag.

From my personal experience, I have never had a problem with heat deformation of the pipe exiting my heater. I also have had experience bending PVC pipe with a heat gun and you have to get it much hotter than what a heater could do before it even starts to bend.