According to the property website, the standard dimensions of dn200 flange are 615,484,565 center distance, 30 thickness, 26/25 bolt hole diameter and 20 bolt holes. According to GB9 1 19-2000, the outer diameter is 6 15, and the inner diameter has two series, one is 462 and the other is 484, with a center distance of 565 and a thickness of 35.