Historical
ASME B16.3-2006
Malleable Iron Threaded Fittings: Classes 150 and 300
This Standard covers malleable iron threaded fittings, Classes 150 and 300. It also contains provisions for using steel for caps and couplings in class 150 for NPS 3/8 and smaller. This standard includes pressure-temperature ratings, size and method of designating openings of reducing fittings, marking, material, dimensions and tolerances, threading, and coatings.
American Society of Mechanical Engineers [asme]