If a sprinkler is color coded Red, what color bulb does it use?

• A. Purple
• B. Blue
• C. Orange/Red
• D. Yellow/Green

Answer: (A)

Sprinkler heads use color coding to quickly show their activation temperature. The body color and the glass bulb color are paired to indicate this rating. When a sprinkler has a red body, the corresponding bulb color used for that rating is purple. So the purple bulb is the correct visual match for a red-coded head. The other bulb colors map to different body colors, so they don’t fit with a red body. This system helps inspectors and firefighters quickly identify which heads will operate at what heat level and choose replacements that match the intended rating.