... NECK FLANGE, BLIND FLANGE. Pressure Class: 75, 150, 300, 400, 600, 900 ASME/ANSI B16.36: (ORIFICE FLANGES) WELDING NECK FLANGE, SLIPON FLANGE, THREADED FLANGE. Pressure Class: 300, 400 ... , 2500 MSS SP44: WELDING NECK FLANGE, BLIND FLANGE. Pressure Class: 300, 400, 600, 900 API 6A: WELDING NECK FLANGE, THREAD FLANGE, BLIND FLANGE. Pressure: 2000Psi, 3000Psi, 5000Psi ...