By nominal pressure:
(1) Vacuum valve: refers to the valve whose working pressure is lower than the standard atmospheric pressure.
(2) Low pressure valve: refers to the valve with nominal pressure PN ≤ 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.
By operating temperature:
(1) Ultra-low temperature valve: valve used for medium working temperature t<-101℃.
(2) Normal temperature valve: valve for medium working temperature -29℃ (3) Medium temperature valve: valve for medium working temperature 120℃ (4) High temperature valve: valve used for medium working temperature t>425℃. By drive mode: According to the driving method, it can be divided into automatic valve, power driven valve and manual valve. By nominal diameter (1) Small diameter valve: valve with nominal diameter DN≤40mm. (2) Medium-diameter valve: a valve with a nominal diameter of DN of 50 to 300mm. (3) Large-diameter valve: a valve with a nominal diameter of DN of 350 to 1200mm. (4) Extra large diameter valve: valve with nominal diameter DN ≥ 1400mm By structural features Valve Structural Features The structural characteristics of the valve can be divided into: (1) Gate shape: the closing member moves along the center of the valve seat; such as a globe valve (2) Plug and ball: the closing member is a plunger or a ball, which rotates around its own centerline; such as a plug valve, a ball valve (3) Gate shape: the closing member moves along the center of the vertical valve seat; such as gate valve, gate, etc. (4) Swing shape: the closing member rotates around the shaft outside the valve seat; such as swing check valve, etc. (5) Butterfly: The disc of the closing member rotates around the shaft in the valve seat; such as butterfly valve, butterfly check valve, etc. (6) Slide valve shape: the closing member slides in the direction perpendicular to the channel.
