Has anyone had experience designing a plastic tank with ¼” and 1/8” female npt threads or fittings. I would like to be able to install and remove NPT male threaded parts into this plastic tank but I don’t really know how to design these interfaces.  I see that female NPT metal inserts exists but that might require a thicker wall thickness than I’d like.

The tank will be production rotomolded and I would like to rapid prototype the tank with the same or similar features.