1. How do the pressures of ultra high pressure valves, high pressure valves, medium pressure valves, and low pressure valves differ?

Ultra high pressure valve, nominal pressure PN≥100MPa; high pressure valve, nominal pressure PN10.0MPa-80.0MPa; medium pressure valve, nominal pressure PN2.5MPa-PN6.4MPa; low pressure valve PN≤1.6MPa.

2. How to distinguish the calibers of extra large caliber valves, large caliber valves, medium caliber valves and small caliber valves?

Extra large valve, nominal size DN≥1400mm; Large diameter valve, nominal size DN350mm-1200mm; Medium diameter valve, nominal size DN50mm-300mm; Small diameter valve, nominal size DN≤40mm.

3. How are high-temperature valves, heat-resistant valves, low-temperature valves, and ultra-low-temperature valves distinguished?

High temperature valve, medium working temperature is greater than 450 ℃; heat-resistant valve, medium working temperature is above 600 ℃; low temperature valve, medium working temperature is -29 ℃ ~ -100 ℃; ultra low temperature valve, medium working temperature is less than -100 ℃.

4. How is the opening and closing direction of the universal valve specified?

The opening and closing directions of the universal valve are specified as: clockwise to close and counterclockwise to open.

5. How is the minimum stem diameter and minimum stem diameter specified?

The minimum stem diameter refers to the diameter of the part of the stem that contacts the packing. The minimum stem diameter refers to the diameter of the stem thread undercut.