We can supply American standard, British standard, EN Standard, and other special requirements . Both CAST IRON class 150# and class 300# available, and size ranges from 1/8" to 6". The brief introduction as follows :
AMERICAN STANDARD
           MATERIALS : ASTM A-197, ASTM A47
           DIMENSIONS : ASME B16.3, B16.14, B16.39 (UNION DIMENSIONS)
           THREADS : ANSI B1.20.1
BRITISH STANDARD
           MATERIALS: ASTM A-197, ASTM A47 
           DIMENSIONS: BS EN 10242, BS 143 & 1256
           THREADS: ISO 7/1
EN STANDARD
           MATERIALS : ASTM A-197, ASTM A47, EN10242
           DIMENSIONS : ISO49, DIN2950
           THREADS: DIN 2999