Manual balancing valves are calibrated by hand to deliver consistent flow across a system based on full-load condition. They're highly accurate at low flow rates and less costly than automatic balancing valves.

Automatic balancing valves, also known as dynamic balancing valves, are calibrated by the manufacturer and automatically adjust to changing system pressures to deliver consistent flow across the system, regardless of changing pressure conditions. They are easier to use than manual balancing valves.