... Large Diameter Steel Flanges> ,B16.36 etc.. a,Nominal pressure: 150psi (2.0Mpa), 300psi (5.0Mpa), ... GB 1) Nominal pressure: 0.25Mpa ~ 42.0Mpa a, Series 1: PN1.0 PN1.6, PN2.0, PN5.0 ... .0, PN15.0, PN25.0, PN42 (main series) b, Series 2: PN0.25 PN0.6 PN2.5, PN4.0 ... 4000mm 3) The flange structure: Integral flange Unit flange a, threaded flange b, welding flange, welding neck flange, welding ...