# Modeling a Device Characterized by a Cv Value

If you have a Cv value for a valve or other device, you can model it as a component having a flow rate vs dP profile.

Use the equation below to calculate values for the component data table

Use the equation below to calculate values for the component data table

dP = \bigg[ \frac{Q}{Cv}\bigg]^2*\bigg[\frac{ \rho}{62.4}\bigg] |

where:

Q = flow rate in gpm

Cv = valve flow coefficient

dP = pressure drop in psi

rho = fluid density (lb/ft

(Ref. Crane Technical Paper No. 410, pg 2-10)

For a particular valve position, take the corresponding Cv and compute the pressure drop over a range of flow rates. It may be easiest to calculate this in Excel. Below is an example.

Then enter the data as a component in your PIPE-FLO model. Below is an example of a component with a Cv = 150.

For reference to older versions of PIPE-FLO see attachments below.

Q = flow rate in gpm

Cv = valve flow coefficient

dP = pressure drop in psi

rho = fluid density (lb/ft

^{3})(Ref. Crane Technical Paper No. 410, pg 2-10)

For a particular valve position, take the corresponding Cv and compute the pressure drop over a range of flow rates. It may be easiest to calculate this in Excel. Below is an example.

Then enter the data as a component in your PIPE-FLO model. Below is an example of a component with a Cv = 150.

For reference to older versions of PIPE-FLO see attachments below.