Hawco 312-300 1/2" 14 NPT Female Hexagonal Retaining Nut for Detect-A-Fire Heat Detectors (Pack of 6)
Detect-A-Fire® (D-A-F) detectors are the cornerstone of many fire protection systems, providing reliable heat detection for over 75 years. They are designed to sense overheat or fire conditions, typically serving as the initial trigger for suppression systems using clean agents, CO₂, inert gases, wet or dry chemicals, or water.
D-A-F detectors are rate-compensated, offering a distinct advantage over traditional fixed temperature or rate-of-rise detectors. Unlike fixed temperature units, which only activate after reaching a specific heat level, or rate-of-rise detectors, which may false alarm from rapid but harmless temperature changes, D-A-F detectors accurately respond to the actual surrounding air temperature, providing fast and reliable activation regardless of fire growth rate.
The sensitivity of the D-A-F detector comes from its unique design:
The outer shell is made from a rapidly expanding alloy that closely tracks changes in ambient air temperature.
The inner struts, made from a slower-expanding alloy and sealed inside the shell, respond more gradually.
During a slow fire, both shell and struts expand together, triggering the alarm at the preset temperature. In contrast, a transient burst of warm air (up to 40°F/min) may expand the shell slightly but will not trigger the detector, minimizing false alarms common with rate-of-rise devices.
For a fast-growing fire, the shell expands quickly, causing the struts to close and activating the alarm or releasing the extinguishing agent. The faster the fire develops, the sooner the D-A-F detector responds, ensuring rapid, accurate protection.
Pack Includes: 6 × 1/2" 14 NPT Female Hexagonal Retaining Nuts compatible with Detect-A-Fire heat detectors.