When pumps and valves are connected to pipelines, parts of these equipment are also made into corresponding flange shapes, also known as flange connections. Any connection parts that are bolted at the periphery of two planes and closed at the same time are generally called "flange", such as the connection of ventilation ducts, this type of parts can be called "flange parts". However, this connection is only a part of the equipment, such as the connection between the flange and the water pump, it is not easy to call the water pump a "flange type part". Relatively small ones, such as valves, can be called "flange parts".
A gasket is a ring made of a material that can produce plastic deformation and has a certain strength. Most gaskets are cut from non-metallic plates, or made by professional factories according to specified dimensions. The materials are asbestos rubber plates, asbestos plates, polyethylene plates, etc .; asbestos can also be made of thin metal plates (tinplate, stainless steel) Metal-clad gaskets made of non-metal materials;
There is also a wound gasket made of a thin steel tape wound with an asbestos tape. Ordinary rubber gaskets are suitable for applications where the temperature is lower than 120 ℃; asbestos rubber gaskets are suitable for applications where the water vapor temperature is lower than 450 ℃, the oil temperature is lower than 350 ℃, and the pressure is lower than 5MPa. Medium, the most commonly used is acid-resistant asbestos board. In high-pressure equipment and pipelines, lens type or other shape metal gaskets made of copper, aluminum, No. 10 steel, and stainless steel are used. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the processing finish of the sealing surface and the gasket is high.