Popular couplings British Standard Pipe (BSP) threads, also known as Whitworth threads.
The BSPP (parallel) male will mate with a BSPP (parallel) female or a female port. The BSPP male has straight threads and a 30° seat. The BSPP female has straight threads and a 30° seat.
The female swivel BSPP has a tapered nose which seals on the cone seat of the male.
The BSPP (parallel) connector is similar to, but not interchangeable with, the NPSM connector. The thread pitch is different in most sizes, and the thread angle is 55° instead of the 60° angle found on NPSM threads.
This is a dryseal thread, the National pipe tapered thread for fuels. This is used for both male and female ends. This connection is still widely used in fluid power systems, even through itiIs not recommended by the National Fluid Power Association (N.F.P.A.) for use in hydraulic applications.
The NPTF male will mate with the NPTF, NPSF or NPSM female.
The NPTF male has tapered threads and a 30? inverted seat. The NPTF female has tapered threads and no seat. The seal takes piace by deformation of the threads. The NPSM female has straight threads and a 30° inverted seat. The seal takes piace on the 30° seat.
The NPTF connector is similar to, but not interchangeable with, the BSPT connector. The thread pitch is different in most sizes. Also, the thread angle is 60° instead of the 55° angle found on BSPT threads.
A metric standpipe is comprised of three components attached to a male f tting. The components are: a Standpipe, Bite Sleeve and Metric Nut. The nut is placed over the Standpipe, followed by the Bite Sleeve. For DIN light assemblies, a DIN light metric nut is used. For DIN heavy assemblies, a DIN heavy metric nut is used. The Bite Sleeve and Standpipe are selected on the basis of tube O.D.