Classification of valves

According to nominal pressure: (1) Vacuum valve: refers to a valve with a working pressure lower than standard atmospheric pressure. (2) Low pressure valve: refers to a valve with a nominal pressure PN ≤ 1.6Mpa. (3) Medium pressure valve: refers to valves with nominal pressure PN of 2.5Mpa, 4.0Mpa, and 6.4Mpa. (4) High pressure valve: refers to a valve with a nominal pressure PN of 10.0Mpa to 80.0Mpa. (5) Ultra high pressure valve: refers to a valve with a nominal pressure PN ≥ 100.0Mpa. According to working temperature: (1) Ultra low temperature valve: used for valves with medium working temperature t<-101 ℃. (2) Room temperature valve: used for valves with medium working temperature -29 ℃<t<120 ℃. (3) Medium temperature valve: used for valves with medium working temperature of 120 ℃<t<425 ℃. (4) High temperature valve: used for valves with medium working temperature t>425 ℃. According to the driving mode, it can be divided into automatic valves, power driven valves, and manual valves. According to nominal diameter (1), small diameter valves: valves with nominal diameter DN ≤ 40mm. (2) Medium diameter valve: a valve with a nominal diameter DN of 50-300mm. (3) Large diameter valve: a valve with a nominal diameter DN of 350-1200mm. (4) Extra large diameter valve: valves with nominal diameter DN ≥ 1400mm