Production of large flange, large flange factory price large flange butterfly: easy to install, flexible position; the body Chenjiao-seat, extend the service life; valve plate can be bi-directional pressure, excellent sealing performance; applies to both liquid media , also applies to gas medium; can be used for the emptying pipe end use; configure a variety of materials, application of different media; performance of anti-erosion, to adapt to the environment of the more harsh conditions; center plate structure, hoist torque small; may be used for medium truncation and adjustment. The large flange butterfly apply as the opening and closing devices such as air, water, steam and oil industrial pipeline. Large flange connecting the two pipes, pipe fittings or equipment, between the first respective fixed on a flange, the two flanges, plus flange gasket, fastened together by bolts to complete the connection. Fittings and equipment already comes with a flange, also belongs to the flange connection. The large flanges points the threaded flange connection (wire connected) and welded flanges. Low voltage small diameter wire connected to the flange, the high and low pressure large diameter are used the weld flange, the thickness of the flange and the connection of the bolt diameter and number of the different pressures is different. Large flange gasket according to the different levels of pressure, there are different materials, from a low pressure asbestos pad pressure asbestos pad to the metal pad has. The flange connections easy to use, able to withstand greater pressure. Large flange nominal pressure determine the maximum operating pressure of the flange, operating temperature and flange material. Because formulated flange dimension series calculated flange thickness mechanical properties 16MnR 200 ℃ benchmarking. Therefore, the provisions flange dimensions determined on this basis, 200 ℃, its maximum allowable operating pressure is considered to have the size flange nominal pressure. The so-called the nominal pressure PNO.6MPa the flange means having such a specific size of the flange, the flange is manufactured with 16MnR at 200 ℃, its maximum allowable operating pressure of 0.6MPa. If this PN0.6MPa flange is used under conditions of higher than 200 ℃, then its maximum operating pressure will be less than its nominal pressure 0.6MPa. Conversely, if it is used under the condition of lower than 200 ℃, based upon the 200 ° C to determine the maximum working pressure. If the material of the flange is replaced by Q235-A, then the mechanical properties of the Q235-A steel 16MnR worse than this a nominal pressure PN0.6MPa flange, even at 200 ℃ operation, its maximum allowable operating pressure will also be lower than its nominal pressure. Conversely, if the material of the flange is replaced by 16MnR 15MnVR, then, because of the mechanical properties superior 15MnVR 16MnR the nominal pressure PN0.6MPa of the flange, in the operation of 200 ° C, and its maximum allowable operating pressure will be higher than the its nominal pressure. In short, as long as the nominal diameter of the flange, nominal pressure determined flange will determine the size. As for this flange allows maximum operating pressure is, it depends on the operating temperature of the flange and what materials manufacturing. The large flange connection so