How does a water flow regulator work

The principle of operation of a direct action flow regulator is based on maintaining a constant pressure drop across the throttling device with a constant hydraulic resistance. A constant pressure drop across the valve with a constant hydraulic resistance ensures a constant flow through it. In water flow regulators capable of maintaining a range of flows, the hydraulic resistance of the throttling element on which a constant pressure drop is maintained is changed during adjustment.

In practice, an automatic water flow regulator combines two devices - a balancing valve and a pressure differential regulator that closes when the maintained value is reached, with impulse tubes inserted before and after the balancing valve.

question : comment : feedback