Minimum flow is not the stopped condition
Specify the lowest production flow that still needs valid measurement, such as a recirculation loop, small batch or slow transfer. Describe stopped flow separately. If start-up and shutdown must also be measured, record their flow rates, durations and whether the measuring section remains full.
Normal flow describes the main operating condition
Normal flow is the most common operating point or range; it is not automatically half the maximum. If recipes, batches or seasons differ substantially, provide several typical points and their share of operating time so that comparisons represent real use.
- For a continuous process, provide a representative flow trend.
- For batching, provide the flow profile over time and the target batch quantity.
Separate sustained maximum from short peaks
State the maximum continuous flow and any brief peaks, such as start-up surges. Do not treat a peak as a sustained condition or disregard it solely because it is short. Check pressure loss, velocity and output range at the peak; short batches also require consideration of response and totalisation.
Use consistent units and reference conditions
An example worksheet might list minimum 100 kg/h, normal 1000 kg/h and continuous maximum 2000 kg/h, with peaks recorded separately. These are illustrative entries, not a meter rating. Gas volume needs actual or standard conditions and the reference temperature and pressure. Converting liquid volume to mass requires the density used and its associated temperature.
