Large diameter flat焊接 flanges possess all the characteristics of flat welding flanges. They are primarily manufactured through CNC lathe, semi-automatic lathe, and drilling machine processing.

Material mainly consists of carbon steel, such as Q235, Q345, 20#, 16Mn, etc. Large-diameter flat welding flanges are mainly in compliance with standards such as Flat Plate Flanged Steel Pipe Fittings - GB9119, Raised Face Plate Flanged Steel Pipe Fittings - GB9119, Flat Flanged Steel Pipe Fittings with Neck - GB9116, and Raised Face Flanged Steel Pipe Fittings with Neck - GB9116. Exported flange products are generally packed in wooden boxes or shock-absorbing film. They are generally suitable for large-scale pipeline systems and large structural mechanical components.

Large-diameter flat welding flanges have holes for bolt passage, securing the flanges together, with a gasket used for sealing between them.

When determining the size of a large diameter flat weld flange, it is necessary to know the nominal diameter and nominal pressure of the flange. The nominal diameter of the pressure vessel flange should be the same series as the nominal diameter of the pressure vessel. For example, a pressure vessel with a DN 1000mm should be matched with a DN 2000mm large diameter flange.

The determination of the nominal pressure for large diameter flat焊接 flanges is related to the operating pressure, operating temperature, and the material of the flange. Because the mechanical properties of 20MnR at 250℃ were used as the basis for establishing the flange size series and calculating the flange thickness. Therefore, the flange sizes determined by this basis are considered to have the nominal pressure at 200℃.