Common 07 – Cv or Kv Control Valve Coefficients
There are many different types of components and control valves on the market. Each may have different flow / pressure loss characteristics. Control valve manufacturers usually publish a Cv flow coefficient or a Kv flow coefficient that defines the flow / pressure loss characteristics of the valve. Cv or Kv flow coefficients are also sometimes used to specify the flow versus pressure drop characteristics of a partially closed balancing valve.
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.
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.
The Component object is used to model a control valve with Cv or Kv characteristics.
Three ways to add a Component with a Cv or Kv flow coefficient to a pipe:
a) Click on the pipe to highlight it and then click the Add/Edit Component button on the pipe pane
to display the 'Component Pressure Loss' screen.
b) Click on the pipe to highlight it and then Right Click and select the Add/Edit Component from
the Popup Menu.
c) Select the Add Component button from the tool bar (the component cursor appears) then click
the pipe where the component is to be added.