ASME B16.1 - 2015 Gray Iron Pipe Flanges and Flanged Fittings

ASME B16.1-2015 Gray Iron Pipe Flanges and Flanged Fittings Classes 25, 125, and 250

ASME B16.1covers Classes 25, 125, and 250 Gray Iron Pipe Flanges and Flanged Fittings. 

It includes (a) pressure–temperature ratings (b) sizes and method of designating openings of reducing fittings (c) marking (d) materials (e) dimensions and tolerances (f) bolting and gaskets (g) pressure testing

Material Class

In those sizes and pressure-rating class designations, where ASTM A 126, both Classes A and B iron, can be used, see para. 6.1, letter A or B shall be cast on both flanges and fittings in the proximity of the numerals. Flanges and fittings with no A or B Class iron marking shall be considered as Class A iron for rating purposes.

MATERIALS

Castings shall meet the requirements of ASTM A126 for both flanges and flanged fittings, as follows:

Bolting ASTM A307 Grade B bolting material is recommended for gray iron flange assembly. Where gray iron flanges are bolted to steel flanges, see ASME B16.5 for bolting limitations.