The last post Tiny referred to said
It'll say something like 180psi at 70*F
150psi at 100*f,
100psi at 200*F, meaning that as the temperature goes up, the pressure rating goes down. But that's not the same as saying pex can't handle over 100psi.
The first thing is those numbers do NOT appear to be factory ratings do NOT trust them.
They are still very important - most plastic material pressure ratings fall with increasing temperature.
Since many compressors are set to shutdown at 125 I would say that if PEX is factory rated at 150 F and 150 PSI then it would be all right for 125 psi service. Would be a little leery of 150 psi or would want air to be cooled to below 100.
Dan Bentler
