球阀发展演变与工作原理： Evolution and principle of ball valves: 球阀只需要用旋转90度的操作和很小的转动力矩就能关闭严密。完全平等的阀体内腔为介质提供了阻力很小、直通的流道。通常认为球阀最适宜直接做开闭使用，但近来的发展已将球阀设计成使它具有节流和控制流量之用。球阀的主要特点是本身结构紧凑，易于操作和维修，适用于水、溶剂、酸和流水槽钢模具 不锈钢铸件 扭王字块模具 井盖钢模具 标志桩模具 调匝式消弧线圈 风冷控制柜 烤漆龙骨天然气等一般工作介质，而且还适用于工作条件恶劣的介质，如氧气过氧化氢,甲烷和乙稀等。球阀阀体可以是整体的，也可以是组合式的。 The ball valves only need to be closed by spinning 90 degrees and small rotating moments. A fully equal body cavity provides a small, straight flow of resistance to the medium. Ball valves are generally considered to be the most suitable for open and closed operation, but recent developments have designed the ball valves to be used for throttling and controlling flow. Ball valve itself is the main characteristics of compact structure, easy operation and maintenance, and is applicable to water, solvent, acid and gas, such as general work medium, but also is suitable for the working conditions of media, such as oxygen, hydrogen peroxide, methane and PVC, etc. Ball valve body can be integral, also can be combination type