What color bulb indicates high temperature ratings in a sprinkler system?

The bulb that indicates high temperature ratings in a sprinkler system is identified by the color blue. In the context of fire protection systems, sprinkler heads are equipped with glass bulbs that contain a liquid which expands when heated. This expansion causes the bulb to shatter, allowing water to flow from the sprinkler head and suppress the fire.

The coloration of the bulbs serves as a quick reference for determining the activation temperature. Blue bulbs are specifically designed for high-temperature settings, indicating that they will activate at higher temperatures than the other colors. This is crucial in environments where higher ambient temperatures are present or where processes generate significant heat.

Understanding the color coding of sprinkler system components is essential for proper system installation and maintenance. Each color represents a different temperature threshold for activation, ensuring that sprinkler systems can effectively respond to varying fire risks.