An American National Standard. The American Society of Mechanical Engineers (ASME). Revision of ASME B16.4-1998. Date of Issuance: March 30, 2007 . 30 р. This Standard for gray iron threaded fittings, Classes 125 and 250, covers
(a) pressure–temperature ratings
(b) sizes and method of designating openings of reducing fittin
(c) marking
(d) material
(e) dimensions and tolerances
(f) threading
(g) coatings.