What is a kv value?
Kv-value The Kv-value is a parameter defining the flow rate of valves. It describes the amount of water from 5° to 30°C which flows through the valve at a pressure loss of 1 bar. The Kvs-value describes the Kv-value when the valve is 100% open.
Mathematically it is easy to see how, as the authority of a control valve is defined as: N = DPv / (DPv + DPc). Where: DPv = Pressure drop across a fully open control valve DPc = Pressure drop across the remainder of the circuit.
What is meant by valve authority?
Valve authority is a term used to describe the basis on which a Control Valve is selected. To calculate the authority, the pressure drop across the Control Valve in fully open position has to be considered, as the pressure drop across the valve is at its minimum in the fully open position.
How does PICV valve work?
By changing the open space through which the water flows within the valve, the flow rate can be adjusted and set. The pressure across the seat of the PICV is held constant by the differential pressure controller. Whilst setting, the open area around the disk will change resulting in a change to the flow rate.
How do you measure a control valve?
When sizing a control valve, the rule of thumb is to size it so that it operates somewhere between 20-80% open at maximum required flow rate and whenever possible, not much less than 20% open at the minimum required flow rate.