Which component is a two-piece link that melts or fuses when heated and is used in sprinklers, fire doors, dampers, and ventilators; held together by a metal that melts or fuses at a specific temperature?

Which component is a two-piece link that melts or fuses when heated and is used in sprinklers, fire doors, dampers, and ventilators; held together by a metal that melts or fuses at a specific temperature?

• A. OS&Y
• B. Fusible Link
• C. Thermocouple
• D. PIV

Answer: (B)

The main concept is a temperature-sensitive device used to hold fire-protection components in place and release them when heat is present. This two-piece link is held together by a metal that melts at a specific temperature, so exposure to the design heat causes the link to fuse apart and activate the connected mechanism. This is exactly what a fusible link does: it keeps sprinklers, fire doors, dampers, and ventilators in their resting positions until the fire heat reaches the melting point, at which point the linkage fails and the system can operate to control the fire or smoke. The other options describe equipment that serves different purposes—valves or a temperature sensor—not a heat-activated, melting connection.

The main concept is a temperature-sensitive device used to hold fire-protection components in place and release them when heat is present. This two-piece link is held together by a metal that melts at a specific temperature, so exposure to the design heat causes the link to fuse apart and activate the connected mechanism. This is exactly what a fusible link does: it keeps sprinklers, fire doors, dampers, and ventilators in their resting positions until the fire heat reaches the melting point, at which point the linkage fails and the system can operate to control the fire or smoke. The other options describe equipment that serves different purposes—valves or a temperature sensor—not a heat-activated, melting connection.