head loss through nozzles 1

[butli]

Hi

I'm trying to calculate the total head for a pump which i'm designing to pump water through a nozzle, I know the static head and the friction head but i'm just wondering if anyone knows how to calculate the nozzle head. The system is quites simple, the pipe is 150mm NS and the nozzle at the end is 40mm NS.

Assistance or ideas will be appreciated.

 

[katmar]

butli,

There are so many different patterns and brands of nozzles that I would be very reluctant to refer you to any generic pressure drop data. The supplier of the nozzle will be able to give you a curve of pressure drop against flowrate, or maybe he will give the data to you as a K value or a Cv value. Either way, you will be better off getting the right data from the supplier.

regards
Harvey

 

[StephenA]

For a sudden contraction from 150 to 40mm the head loss is approximately 0.5*V*V/(2g) where V is the velocity in the smaller pipe, (or is this too simple?)