# A Relation between Headloss Coefficient and Discharge Coefficient

1. Jun 24, 2016

Hi
Have a look at this formula:
Cv=((39.693*D^4)/K)^0.5
It correlates Discharge Coefficient (Cv) for a valve with Headloss coefficient (K) of the valve.
Please explain this formula and let me know:
1- Is K fixed for a valve in every situations of it?
2- Assume an area of a valve is changed during the time. Which are Cv, K or D fixed and which are changed?
3- Is K fixed during valve's area changing?
Thank.

2. Jun 29, 2016