The  British Standard Pipe  (BSP) is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external (male) with an internal (female) thread. Two types of threads are distinguished: BSPT : British Standard Pipe Taper -also known as “R” or “Rc” threads BSPP : British Standard Pipe Parallel -also known as “G” or “Rp” threads Parallel (‘straight’) threads, British Standard Pipe Parallel thread (BSPP; originally also known as British Standard Pipe Fitting thread/BSPF and British Standard Pipe Mechanical thread/BSPM), which have a constant diameter; denoted by the letter G. Taper threads, British Standard Pipe Taper thread (BSPT), whose diameter increases or decreases along the length of the thread; denoted by the letter R. These can be combined into two types of joints: Jointing threads: These are pipe threads where pressure-tightness is made through the mating of two threads together. They always