Italian
In industry, butterfly valves are divided into two main categories based on the sealing material, which determines how much "temperament" (temperature and pressure) they can withstand:
| Character | Soft-sealed | Hard-sealed |
| Sealing material | Rubber, Fluoroplastics(PTFE) | Metals, Graphite, Alloys |
| Leakproofness | Excellent (achieves zero leakage at the bubble level) | Slightly inferior to soft seals |
| Character | Soft-sealed | Hard-sealed |
| Temperature Resistance | Poor (usually less than 150°C, as the rubber will melt) | Extremely strong (can withstand temperatures of several hundred degrees Celsius) |
| Dielectric Strength | Low- and Medium-Voltage | High Voltage |
| Applicable Scenarios | Drinking Water, Wastewater, Air Conditioning Systems, Food and Beverages | Metallurgy, Thermal Power and Steam, Petrochemicals, Natural Gas |