Soft-seated butterfly valves are suitable for use in hot and cold water systems up to 100°C. If the system requires higher temperatures, a metal-sealed butterfly valve (can be used in systems up to 500°C) can be used.
NBR ≤ 80°C, EPDM ≤ 120°C, PTFE ≤ 150°C.
The maximum operating temperature in acid-alkali media is:
Neoprene: nitric acid (10%) 29°C; Citric acid 29°C; Sodium hydroxide 93°C.
2. Butyl rubber: sulfuric acid (50%) 66°C; Nitric acid (10%) 40°C; Sodium hydroxide 85°C.
F4: sulfuric acid (0-100%) 180 °C; Nitric acid (0-100%) 180°C; Sodium hydroxide 180°C.