Flow Rate Conversion Guide
Flow rate measures the volume or mass of fluid passing through a point per unit time. Volumetric flow rate (m³/s, L/min, GPM, CFM) and mass flow rate (kg/s, lb/h) are distinct quantities linked by fluid density.
Key conversions: 1 m³/h = 4.4029 GPM (US), 1 GPM = 3.78541 L/min, 1 CFM = 1.699 m³/h = 28.317 L/min, 1 m³/s = 35.3147 ft³/s. For mass flow: 1 kg/s = 7,936.6 lb/h.
Flow rate conversion is essential in process engineering (pipe sizing), HVAC (air handling unit selection in CFM), water treatment (plant capacity in MGD), chemical dosing (mL/min), and oil and gas (barrels per day).
Critical pitfalls: confusing volumetric and mass flow rates (they are only approximately equal for water near 4°C), not specifying standard vs. actual conditions for gas flow (SCFM vs. ACFM can differ by 5x at high pressure), assuming GPM means US gallons without verifying (Imperial GPM is 20% larger), and neglecting that gas volumetric flow rate changes dramatically with temperature and pressure.