Volumetric flow rate, also known as discharge volume or nameplate flow rate in China, is the volume of gas discharged by an air compressor per unit time at the required discharge pressure. This volume is converted to the intake conditions, specifically the volume at the intake pressure, temperature, and humidity at the first-stage intake pipe. In other words, it's the intake volume. According to national standards, an air compressor is considered合格 (qualified) if its actual discharge volume is ±5% of the nominal flow rate.
Theoretically, pressure changes should not affect the discharge volume if the rotational speed remains constant; specifically, they affect the volumetric flow rate, not the mass flow rate. Since the discharge volume we generally refer to is the intake flow rate, it remains unchanged.
