Flange gaskets are sealing elements used in pipe flange connections. Their main function is to fill the flange gap to prevent media leakage, and they are widely used in industries such as petrochemicals, chemicals, and power generation. Gasket selection requires comprehensive consideration of factors such as media properties, working pressure, and temperature, and must comply with national standards and specifications such as GB4622.2 and GB9126.
Based on material, gaskets can be divided into three categories: non-metallic, semi-metallic, and metallic. Non-metallic gaskets are made of rubber, asbestos, or synthetic resin and are suitable for medium and low pressure applications. Semi-metallic gaskets, such as spiral wound gaskets, consist of alternating V/W-shaped metal and non-metallic strips, combining elasticity and pressure resistance, and are suitable for high-temperature and high-pressure environments. Metallic gaskets are made of materials such as steel and copper and are specifically designed for extreme working conditions. Among these, spiral wound gaskets, due to their multi-layer composite structure and inner and outer metal ring design, effectively balance sealing stress and have become the mainstream choice. Different flange sealing surface forms (such as flat and raised face) require specific gasket types to ensure sealing reliability.