There are many different types of Components and Control Valves. Each may have different flow / pressure loss characteristics. Manufacturers of control valves usually publish a Cv flow coefficient or a Kv flow coefficient to describe the flow versus pressure loss characteristics of their control valves in a standardized manner. 


A Cv flow coefficient specifies the volume of water in US gpm at 60°F (15.55°C) that will flow through a valve with a 1.0 psi pressure drop across the valve.


Thus, a Cv flow coefficient of 10 indicates that a 1.0 psi pressure drop will occur with a flow of 10 US gpm of water through the valve. Pressure drop for the different fluids and different flow rates can be calculated from the Cv flow coefficient. 
See Section: Calculation Theory and Methods of Solution section for further information.


A Kv flow coefficient specifies the volume of water in m3/hour at 20°C (68 °F) that will flow through a valve with a 1.0 bar pressure drop across the valve. 


Thus, a Kv flow coefficient of 10 indicates that a 1.0 bar pressure drop will occur with a flow of 10m3/hour of water through the valve. Pressure drop for the different fluids and different flow rates can be calculated from the Kv flow coefficient. 
See Section: Calculation Theory and Methods of Solution section for further information.


The Component object is used to model the flow rate / pressure loss of control valves with Cv or Kv flow coefficients.