What is the term for the characteristic where downstream pressure drops as air begins to flow through a pressure regulator?

The term that describes the characteristic where downstream pressure drops as air begins to flow through a pressure regulator is known as "droop." This phenomenon occurs because the pressure regulator is designed to maintain a set downstream pressure, but when flow demand increases, the pressure can temporarily drop until the regulator adjusts to the new flow condition. This behavior is particularly important in pneumatic systems, as it influences the system's performance and response to varying demands.

Understanding droop is crucial for the design and application of pneumatic systems, as it impacts efficiency and operational stability. Engineers must consider this effect when selecting regulators to ensure they meet the requirements of the system under different flow conditions. Properly accounting for droop ensures that downstream applications receive the necessary pressure for optimal performance.