Quote:
Originally Posted by Rusty
That depends on the plastic used. At work, I've seen PVC hold hydrogen gas with no problems, then seen it leak through the wall of the PVC using plant air. Go figure.  |
One is likely to run into only two grades of PVC pipe at the local hardware store: building grade and piping grade. As far as gas permeability goes, there's not much difference between the two. Both are pretty much airtight when put together properly. If it will hold Hydrogen (I have my doubts but will take your word for it), it will hold anything you or I are likely to put in it.
FWIW, I would consider PVC pipe to be a very poor choice of materials to use in a car. It becomes brittle when cold and soft when warm (max working temperature is only 140F for building grade PVC). If one must use PVC, the method that uses two large caps looks like it would be the strongest.