According to connection method classification (1) threaded connection valves: valve with internal thread or externalthread, and pipe thread connection.
按连接方法分类(1)螺纹连接阀门：阀体带有内螺纹或外螺纹，与管道螺纹连接。
2
Both have the same pitch diameter at the top of the hole of internal threads or end of the pipe on external threads, and both have the same thread lengths or depths.
在内螺纹的孔的顶端或者外螺纹的管的端部拥有相同的中径，而且拥有相同的螺纹长度和深度。
3
Germany RBT import externalthread needle valve can be equipped with stainless steel welded pipe, and pipeline butt welding connection, but also through the outer nut removing the valve.