The color of a sprinkler head rated 135 ° to 170 ° F is

• A. Uncolored or black
• B. Blue
• C. Red
• D. Green

Answer: (A)

Temperature rating is shown on sprinkler heads by color to let you identify the activation temperature at a glance. The 135–170°F range is considered the ordinary rating, and sprinkler heads in this range are typically uncolored or black. This minimal coloring is used so the head’s lower-temperature category isn’t mistaken for higher-rated ones, while higher ratings use noticeable colors to differentiate them. In practice, this visual cue helps installers and inspectors quickly verify the right head is used for the environment, ensuring the sprinkler will activate at the intended ambient temperature. Always cross-check with the manufacturer’s data, but in this context uncolored or black signals the 135–170°F rating.