In many processes, it may be necessary to minimize dangerous product leakage and maintain effective shutoff of a valve. Valves that satisfy this condition are known as fire-safe.
This term fire-safe is one of the least understood valve specifications. To date, there is no test protocol to establish whether a valve is fire-safe.
The common definition used for a fire-safe valve is when a valve is exposed to fire conditions, it will allow minimal leakage through the seat and stem, and continue to provide effective shutoff during or following a fire or exposure to excessive temperatures.
Gate and globe valves made from metals that do not melt during a catastrophic fire have also been classified as fire-safe.
Their design and construction assured metalto-metal seating before, during and after a fire. Butterfly valves are commonly manufactured with a “tandem” soft seat over metal to achieve a fire-safe application.