... 4)standard:DIN,ASME,API THREAD FLANGE specifications Forged Steel Flanges:(1).ASME/ANSI B16.5 : WELDING NECK FLANGE, SLIP-ON ... , 600 , 900(3). ASME/ANSI B16.36 : (ORIFICE FLANGES) WELDING NECK FLANGE, SLIPON FLANGE, THREADED FLANGE.Pressure Class :300, 400 ... Class :300, 400 , 600 , 900(6).API 6A :WELDING NECK FLANGE, THREAD FLANGE,BLIND FLANGE.Pressure :2000Psi, 3000Psi, 5000Psi, 10000Psi, 15000Psi ...