According to American national standards, where must shut off valves be installed for pumps below the waterline?

Shut off valves are critical components in pool systems that control the flow of water. According to American national standards, when pumps are positioned below the waterline, the requirement is to install shut off valves on the discharge lines. This is because the discharge line is where water is expelled from the pump, and having a shut off valve in this location allows for the easy isolation of the pump for maintenance or repairs without draining the entire system.

Installing valves on the discharge lines ensures that the water can be directed appropriately, and it prevents backflow into the pump when maintenance is needed. By installing these valves in the correct location, it provides a safer and more efficient way to manage the system during those necessary maintenance periods, aligning with standards set for safe operational practices in commercial pool management.