When it comes to pvc I have personal experience.
I built a filter out of 4" fittings and it wound up as shattered shards of s#&t on the far side of the garage.
On the other hand I run 1\2" pvc from the compressor to my new filter/distribution manifold and have had no trouble at all.
My lesson was that large pipe=large surface area and more psi/square in.
That said, my 1/2" pvc still runs Outside the house/garage up against the soffat where if it were to let go it would do no harm.
On a side note I use a small Aluminium heater core as a condenser before my entry point... so the idea that radiators can't handle any pressure past 15 or 20psi is BS.
JMO
