The BSPT connection is similar to National Pipe Tapered Fuel (NPTF), except the thread pitches are different in most sizes. The thread form and outside diameters are close, but not the same. Sealing is accomplished by thread distortation.
Bsp fitting (BSPP and BSPT) fittings made from Type 316 Stainless Steel for maximum corrosion resistance. Stainless steel bsp multiseal fitting is recommended for marine applications, chemical processing and other harsh operating conditions.