There are reasons not to use PVC for through hull connections, although it is certainly easy to fabricate, cheap and impervious to corrosion.
It is much more brittle than stainless, or bronze or the original copper. It can fail it something hits it or someone steps on it or from long term vibration. I know, I know, such a thing is very unlikely, but the first rule of sailing is to keep the water out of the boat--always.
In the event of a fire, PVC would have a very short life span before it fails and water floods the boat. PVC begins to seriously soften at temperatures as low as 140F, which is not that far above an Amel engine room on a hot sunny day in the tropics with the engine running.
If plastic still seems like a good idea, use schedule 80 pipe AND fittings for extra strength and use CPVC, not PVC, for it's higher temperature rating. Also, if you use plastic hose barbs be sure they meet the same strength and temperature specs--they are not easy to find. I have had too many PVC and nylon hose barb adapters break off while removing hoses to ever trust them on through hulls.
There are plastics that can be reliably used in through hull applications (Marelon comes to mind) but PVC? Not so sure...
Rose Island, Bahamas
---In amelyachtowners@..., <onboardaphrodite@...> wrote :
I made a new manifold out of PVC