Historical
ASME B16.39-2014
Malleable Iron Threaded Pipe Unions: Classes 150, 250, and 300
This Standard covers threaded malleable iron unions, classes 150, 250, and 300.It also contains provisions for using steel for NPS 1/8 unions. This Standard includes requirements for design, pressure-temperature ratings, size, marking, materials, joints and seats, threads, hydrostatic strength, tensile strength, air pressure test, sampling, coatings, and dimensions.
American Society of Mechanical Engineers [asme]