法兰也称法兰盘，通常是指在一种在周边开上几个固定用的孔用于连接的连接件。在机械上应用广泛，形式形状也千奇百怪，只要像就是叫法兰盘，来源于英文flange。用于管件连接中间的介质，是一种能产生塑性变形、并具有一定强度的材料制成的圆环（现在也有非圆形的法兰连接）。大多数垫片是从非金属板裁下来的，或由专业工厂按规定尺寸制作。
Flanges, also known as flanges, usually refer to connectors with several fixed holes in the periphery for connection. It is widely used in machinery and has various forms and shapes. As long as it looks like a flange, it comes from English flange. The medium used to connect the middle of pipe fittings is a circular ring made of a material that can produce plastic deformation and has certain strength (now there are also non-circular flange joints). Most gaskets are cut from non-metallic sheets or are manufactured by specialized factories in accordance with specified sizes.
法兰盖也称盲板法兰、盲板。是中间不带孔的法兰，供封住管道堵头用。作用与焊接封头及丝扣管帽是一样的，只不过盲板法兰和丝扣管帽可以随时卸下来，而焊接封头则不行。密封面的形式种类较多，有平面、凸面、凹凸面、榫槽面、环连接面。
Flange cover is also called blind flange and blind plate. It is a flange without holes in the middle for sealing the pipe plug. The function is the same as that of the welded head and the screw cap, except that the blind flange and the screw cap can be removed at any time, while the welded head can not. There are many types of sealing surface, such as plane, convex, concave and convex, tenon and groove surface, and ring connection surface.