THREADED FITTINGS

Threaded fittings feature NPT, BSPT, or metric threads for easy installation without welding, making them ideal for maintenance, repairs, and low-to-medium pressure applications in plumbing, instrumentation, and process piping. Offered in sizes from 1/8" to 4" and grades like 304, 316, and 316L, they provide corrosion resistance and versatility across sectors.
NPT (National Pipe Thread) are the most popular type of seal for pressure calibration systems. NPT male adapters have a taper thread that wedges into the female NPT adapter. They seal due to the “out of roundness principle” which means that the male stretches the female fitting until there is so much force that the connection can hold pressure.
BSP (British Standard Parallel Pipe) is most popular in the UK, Europe, Asia, Australia, New Zealand and South Africa. It is a parallel thread fitting that uses a bonded seal ring to do the sealing. This bonded ring seal is sandwiched in-between a shoulder on the male fitting and the face of the female fitting and is squeezed in place.
BSPT (British Standard Pipe Taper) is similar to NPT except there are important differences. The angle across the flanks of threads (if you sliced the fitting in half long-ways and measured the angle from root to crest to root) is 55 degrees instead of 60 degrees as it is for NPT. Another important difference is that for many BSPT pipe sizes the thread pitch is different than NPT. Thus an NPT male will sometimes fit into a BSPT fitting or vice versa but they will not seal.