Which bulb color would indicate the highest activation temperature in a sprinkler system?

The color of the bulb in a sprinkler system is indicative of the temperature at which the sprinkler will activate. In this context, the blue bulb is designed to indicate the highest activation temperature among the options provided.

The different colors correlate to specific temperature ratings: red generally signifies a low activation temperature, yellow corresponds to a moderate range, green indicates a higher temperature, and blue is associated with the highest activation temperature commonly found in such systems. This hierarchy ensures that sprinklers can be appropriately chosen based on the environmental conditions they will be exposed to, enabling effective fire suppression.

In applications requiring higher temperature thresholds (such as areas that may experience warmer ambient conditions), the use of blue bulbs ensures that the sprinklers will only activate under the appropriate fire conditions, thus preventing nuisance activations while still providing the necessary protection.