法兰为带凸缘的零件。法兰可以是单独的，叫做法兰盘，也可以是组合型的，如阀门两端的法兰，便于安装螺栓。 Flanges are flanged parts. Flanges can be separate, called flanges, and can also be composite, such as flanges on both ends of the valve, to facilitate the installation of bolts. 一、钢制管法兰中国机械行业阀门连接法兰标准 One, steel pipe flange China machinery industry valve connection flange standard JB/T 74 管路法兰 技术条件 JB/T 74 pipeline flange technical conditions JB/T 75管路法兰 类型 JB/T 75 line flanges JB/T 79.1 凸面整体铸钢管法兰 JB/T 79.1 integral cast steel pipe flange JB/T 79.2 凹凸面整体铸钢管法兰 JB/T 79.2 integral cast steel pipe flange JB/T 79.3 榫槽面整体铸钢管法兰 JB/T 79.3 on the whole cast steel pipe flange JB/T79.4 环连接面整体铸钢管法兰 Integral cast steel pipe flange for JB/T79.4 ring JB/T 81 凸面板式平焊钢制管法兰 JB/T 81 convex flat steel pipe flange JB/T 82.1 凸面对焊钢制管法兰 JB/T 82.1 convex welded steel pipe flange JB/T 82.2 凹凸面对焊钢制管法兰 JB/T 82.2 concave to weld steel pipe flange JB/T 82.3 榫槽面对焊钢制管法兰 JB/T 82.3 mortise groove face weld steel pipe flange JB/T 82.4 环连接面对焊钢制管法兰 JB/T 82.4 ring joint welded steel pipe flange JB/T 83 平焊环板式松套钢制管法兰 JB/T, 83 flat welded ring-plate steel pipe flange JB/T 84 凹凸面对焊环板式松套钢制管法兰 JB/T 84 concave facing the welded ring flat steel pipe flange JB/T 85 翻边板式松套钢制管法兰 JB/T 85 flanging sheet steel pipe flange JB/T 86.1 凸面钢制管法兰盖 JB/T 86.1 convex steel pipe flange cover JB/T 86.2 凹凸面钢制管法兰盖 JB/T 86.2 concave steel pipe flange cover 二、钢制管法兰中国国家阀门连接法兰标准 Two, steel pipe flange China national valve connection flange standard GB/T 9112 ~ GB/T 9124-2000 钢制管法兰，整体钢制管法兰的法兰密封面形式有平面、突面、凹凸面、榫槽面和环连接面。 GB/T 91112 ~ GB/T 9124-2000 steel pipe flanges, integral steel pipe flanged flanged flanged cover in the form of flat, surface, concave convex, mortise and ring. GBT 9112 钢制管法兰 类型与参数 GBT 9112 steel pipe flange type and parameters GBT 9113.1 平面、突面整体钢制管法兰 GBT 9113.1 plane, integral steel pipe flange GBT 9113.2 凹凸面整体钢制管法兰 GBT 9113.2 integral steel pipe flange GBT 9113.3 榫槽面整体钢制管法兰 GBT 9113.3 mortise steel pipe flange GBT 9113.4 环连接面整体钢制管法兰 GBT 9113.4 ring joint integral steel pipe flange GBT 9114 突面带颈螺纹钢制管法兰 GBT 9114 flanged flanged flanged flange GBT 9115.1 平面、突面对焊钢制管法兰 GBT 9115.1 plane, face welding steel pipe flange GBT 9115.2 凹凸面对焊钢制管法兰 GBT 9115.2 concave and convex to face welded steel pipe flange GB/T 9115.3 榫槽面对焊钢制管法兰 GB/T 9115.3 tenon for welding steel pipe flange GB/T 9115.4 环连接面对焊钢制管法兰 GB/T 9115.4 ring welded steel pipe flange GB/T 9116.1 平面、突面带颈平焊钢制管法兰 GB/T 9116.1 flat, flanged flanged steel pipe flange GB/T 9116.2 凹凸面带颈平焊钢制管法兰 GB/T 9116.2 concave convex and flanged steel pipe flanges GB/T 9116.3 榫槽面带颈平焊钢制管法兰 GB/T 9116.3 tenon with neck flat welded steel pipe flange GB/T 9116.4 环连接面带颈平焊钢制管法兰 GB/T 9116.4 ring joints with neck flat welded steel pipe flange