[Van Lew]

CS wrote in news:11b8e186-0d18-4d13-8a3b-
:

I am looking at getting some water filters, 20 inch housings, with 3/4
inch NPT female connections in plastic tops. Can I get away with
screwing in 3/4 BSP TAPER male brass compression fittings, using a
good wind of PTFE tape??
Both NPT and BSPT are 14 TPI and the nominal NPT is 1.050 inch OD and
BSPT is
fractionally smaller at 1.041 inch OD, so should fit in. I know that
there is a 5 degree difference between thread angle.

TVMIA

I'm in the hose and fittings business so I deal with this pretty often.
Generally we say not to try it on a hydraulic system, but sometimes you
can get away with it on a pneumatic system because the preasures are much
lower. I'd suggest just finding compression fitings with NPT threads.
VV