In sprinkler systems, what is the common term for horizontal piping that may have sprinkler heads installed directly on it?

The correct choice is the term commonly used to refer to the horizontal piping that serves multiple sprinkler heads directly. This piping connects individual sprinkler heads within a particular area or zone of a system, allowing water to be distributed effectively from the main supply to the heads. The branch line is crucial in ensuring that water reaches each sprinkler head at the correct pressure and flow rate, providing adequate coverage for fire protection.

The other terms refer to different elements of a sprinkler system. The riser nipple typically refers to a vertical pipe section that connects the main system to the sprinkler heads or other components. The feed main is a larger, main supply pipe that carries water to different branches or zones but does not usually have sprinkler heads mounted directly on it. The cross main connects various feed mains and helps distribute water across a larger area, but again, it is not the section where heads are mounted directly. Understanding these definitions helps clarify the role of each component in a sprinkler system and ensures proper installation and functionality.