The flow rate of a gas is the volume of gas passed in a given period of time. Gas flow rates are commonly measured with devices calibrated in units stated in liters per minute or cubic feet per hour. In most processing situations, the gas flow rate must be set to provide a uniform flow. Controlling the flow requires using valves to adjust the rate of flow. Flowmeters incorporating a metering valve are used to measure and control gas flow rates.

This section provides tutorials on the mechanics of and the selection criteria for variable area flowmeters, and mass flow measurement and control devices. A broad selection of models that include direct reading, calibration, blenders, mass flow, and various meters for use in special applications are in stock and available for immediate delivery.