ASME B16.4-2021 PDF
This Standard for gray iron threaded fittings, Classes 125 and 250 covers: (a) pressure-temperature ratings (b) size and method of designating openings of reducing fittings (c) marking (d) material (e) dimensions and tolerances (f) threading, and (g) coatings.
Upon request, the B16 Standards Committee will render an interpretation of any requirement of the Standard.Interpretations can only be renderedin response to awritten request sentto the Secretary oftheB16 Standards Committee.