Circuit balancing valves for hydronic heating and chilled water, 1/2" through 2", in sweat, threaded, FIP and flanged.
Balancing valves solve the problem that water takes the easiest path. Without them, the loop nearest the pump gets most of the flow and the far zone stays cold, no matter how large the circulator is. The valve introduces a deliberate, adjustable restriction so each circuit receives its design flow.
Manual balancing valves are set once at commissioning, using the pressure ports and the manufacturer's chart to read actual gpm rather than guessing from the handle position. Automatic (pressure-independent) valves hold their set flow as system pressure changes, which is what a variable-flow system with zone valves needs — a manual valve balanced at full flow goes out of balance the moment zones start closing.
Body material is bronze and brass for closed hydronic; cast iron appears in larger flanged sizes. Some models integrate a Y-strainer, which saves a fitting and a joint.
Brands include Taco, Jomar and Caleffi.
