Pressure Regulating Valve or Pressure Regulator, more commonly known as pressure-reducing valves, keep the output pressure as per set value while input pressure or output flow keep changing.
A general purpose PRV is the simplest form that consists of spring-loaded diaphragm, and actuator. The spring is compressed or decompressed by rotating the knob to exert pressure on the diaphragm. The desired output air pressure is achieved by a stem gradually opening or closing the orifice balancing against the diaphragm pressure.
Pressure Regulators typically require a force load pressure to move their internal spring before they can even begin to control. Also, when operating under full capacity flow they have a characteristic known as “droop”. Droop is the term used to quantify the degree the controlled outlet pressure will fall off as the flow through the regulator increases. Since the regulator spring balance is non-linear, the higher the actual outlet operating pressure is from the designed ‘53% Rule’, the poorer the regulator will perform.
