The low pressure header and each branch shall have a 6 mm minimum, non ferrous shutoffvalve for each instrument requiring an air supply and a compression coupling for each air purge connection.
低压头和每个分支应为6毫米，非铁关断阀在每个送风和空气净化压缩为每个连接耦合仪器最低要求。
2
As the shut-offvalve is seated, a passage 41 in its stem connects with ports 42 in the guide bushing 37 so as to allow inlet air to pass though the valve stem to a housing port 44.