Automatic balancing valves are utilised in central heating and cooling systems that rely on flow of water through the system.Pressure independent control valves are used to limit the flow to the fan coil terminal and air handling unit. This flow is not affected by changes in inlet pressure.
source/image(PrtSc): The Engineering Mindset
PICV Pressure Independent Control Valves, in this video we learn how PICV’s work, where we use PICV’s, what they look like, the basic working principles behind them to help you learn mechanical engineering. Watch the video from The Engineering Mindset for more info:
They respond to changes in pressure in order to maintain the desired flow. A diaphragm within the valve keeps the outlet pressure constant, and this delivers a constant flow to the terminal.
The added advantage of pressure independent control valves is that, when fitted with an actuator, they replace the manual balancing valve and motorized control valve with a single valve, thus reducing installation cost.