According to the nominal pressure:

(1) Vacuum Bai valve: refers to the valve whose working pressure is lower than the standard atmospheric Du pressure.

(2) Low pressure valve: refers to the valve with nominal pressure daopn ≤ 1.6Mpa.

(3) Medium pressure valve: refers to the valve with nominal pressure PN of 2.5MPa, 4.0Mpa and 6.4Mpa.

(4) High pressure valve: refers to the valve whose nominal pressure PN is 10.0mpa-80.0mpa.

(5) Ultra high pressure valve: refers to the valve with nominal pressure PN ≥ 100.0mpa.