法兰连接的阀门，其安装和拆卸都比较方便。
Valve flange connection , the installation and removal are more convenient .
1如果法兰与连接件或阀门构成一个整体，则螺栓孔钻在圆心线两侧。
When flanges are integral with fittings or valves , holes for bolts are drilled to straddle the center line .
法兰连接阀门