What is the primary purpose of riser check valves in a sprinkler system?

The primary purpose of riser check valves in a sprinkler system is to prevent backflow of water into the supply line. These valves are installed on the riser, which is the vertical pipe that supplies water to the sprinkler system from the main supply. By preventing the backflow, riser check valves protect the overall water supply system from contamination and ensure that water only flows in one direction—from the supply to the sprinkler heads.

When a fire occurs and the sprinklers activate, the flow of water is directed down to the sprinkler heads for fire suppression. If there is no check valve in place, water could potentially flow back up the riser into the water supply when there are pressure changes, which could introduce contaminants into the potable water supply. Therefore, ensuring the integrity and safety of the water supply while allowing for the effective operation of the fire control system is a critical function of the riser check valve.

The other options, while relevant to a fire sprinkler system, do not accurately describe the specific function of riser check valves. For example, regulating water pressure is typically managed by specialized pressure-reducing valves, not check valves. Likewise, controlling flow to fire hose connections involves different types of valves within the system, and monitoring system integrity is