Valve & Flow Sizing

Valve and flow sizing calculators help HVAC engineers select and verify control valves and hydronic system components. This collection includes tools for calculating the required Kv (with a selection margin) for a design flow and pressure drop, determining the flow or pressure drop through a valve of known Kv, converting between Cv and Kv, and finding the hydronic flow rate a heat load needs. Correct valve sizing is critical to system controllability — an oversized valve hunts and oscillates, while an undersized valve cannot deliver design flow. These calculators apply standard flow coefficient formulas used by valve manufacturers worldwide so results match published catalog data. Use them during design to specify the right valve for each application, or during commissioning to confirm that installed valves are providing the expected flow characteristics and pressure drops.