Which of the following components is NOT part of a fire service main?

A fire service main is a critical part of the water supply system used for firefighting. It typically comprises components such as a water source, pipe connections, and fire hydrants.

The components of a fire service main are designed specifically to deliver water to firefighting equipment effectively. The water source provides the necessary supply, pipe connections are essential for transporting the water, and fire hydrants act as access points for firefighting personnel.

Smoke detectors, however, are primarily fire detection devices used in building safety systems. Their function is to detect smoke and signal an alarm rather than being part of the water delivery system for firefighting. They do not contribute to the physical infrastructure of a fire service main, which is why they are the correct answer in identifying what does not belong in this category.

Understanding the distinct roles of these components helps clarify the structure and function of fire protection systems, emphasizing the importance of each part in responding to fire emergencies.