Electric power standard flange standard flange refers manufactured in accordance with the Ministry of standard flanges. The petrochemical, refining shipbuilding, onshore and offshore oil and gas, pulp and paper, fertilizer, chemical fiber, machinery and equipment manufacturing and other industries and other products used in heat exchange. Flange sealing surface with full flat, convex surfaces, uneven surfaces, tongue and groove, ring groove noodles. Name and type of flange sealing surface of different standards of its flange code, code is slightly different. [1] The sealing surface type selection type: Full flat sealing surface: flat welding type often associated with operating conditions to apply to relatively mild (PNg1.0) conditions; commonly used in cast iron or cast iron flanges connected with steel Lan; convex sealing surface countertops: is the most widely used as a type, it is often the butt and socket weld type used in conjunction with the "American-style flange", commonly used in PN2.0, PN5.0 and some PN10. 0MPa pressure rating; and in the "European-style flange" is commonly used in the PN1.6, PN2.5MPa pressure rating; convex surface sealing surface: often associated with the use of butt and socket type, rarely in the "American-style flange" in adopted in the "European-style flange" common in PN4.0, PN6.4MPa hierarchy. But it is not easy to replace the gasket; tongue and groove sealing surface: usage with convex face flanges; ring groove surface sealing surface: often associated with welded connection type (not with socket weld fit) to use, mainly used in high temperature , high or both higher operating conditions.