... .Size Flange: 3 / 8 "~ 100" DN10 ~ DN2500 Pressure U.S. Series: CLASS 150, CLASS 300, CLASS 400, CLASS 600, CLASS 900 ... , CLASS 1500, CLASS 2500 EU Series: PN 2.5, PN 6, PN 10, PN 16, PN ... , PN 250, PN 320, PN 400 Flange sealing surface type U.S. Series: Flat (FF), suddenly face (RF), groove (G), convex surface ...