[SML] PVC socket cap

[Dougherty, Jim]

I had to do a fair amount of reducing for a recent project, some thoughts:

- What is your municipal water pressure, or rather what is the specific
pressure you¹re working with?  Here, municipal pressure is ~120psi in
places.  Fire engines use their pumps to reduce, not boost, the pressure
sometimes.

- Have you looked at a bulkhead fitting through the cap?  Pretty clean
looking, pretty short, no questionable threads in PVC. Ends with 1/4² M,
not F, if that¹s an issue.
	http://www.mscdirect.com/industrialtools/brass-bulkhead-fittings.html

- Large changes in diameter tend to need multiple fittings.  2² socket to
1/2² NPTF and 1/2²NPTM x 1/4² NPTF might be your shortest option, which
sounds like it might not work.

- I¹ve faked a bulkhead fitting using a reducer on the outside and a
gasket and coupling on the inside; you¹d have something like a 1/4²F x
1/2² M reducer, and a 1/2² coupling on the inside.  Thicker gaskets help
deal with the curve of the cap.

- Jim Dougherty
ATD, Middlebury College Theatre Dept.