This is as a part of high-pressure pipes and to as the pressure from 210Kg/cm².
These fittings are bended to 45º and 90º with short Elbow and long Elbow.
This is as a part of High-Pressure pipes and referred to as the pressure from 120kg/cm² to 350Kg/cm². This is a T-shape Fitting and normally referred to as connecting vertically on the pipes. And Plus many types with straight, Reducing, Cross, Lateral and PAD etc.
Full coupling is referred to as connecting straight pipe on the pipe below 1 1/2B. Half coupling is referred to as distribution parts on the pipe below 1 1/2B.