Pressure Drop due to CSV Valve

[Bubba]

What is the approximate head loss through a CSV1A valve when it's throttling back a 10 GPM pump to say 6 GPM at 60 psi, and also 2 GPM at 60 psi?

 

[Reach4]

Looks like about 3 psi at 6 gpm per https://cyclestopvalves.com/pages/csv1a-specifications

 

[Sponsor]

 

[Valveman]

Head loss from a CSV is only applicable when using all the water the pump can produce. A 10 GPM pump supplying 10 GPM will cause 4 PSI loss across the CSV1A. When ask to make a 10 GPM pump only produce 6 or 2 GPM, the CSV will put as much head loss as needed on the pump to make it do that. Depending on the size of pump, it may take 40 PSI or 100 PSI restriction to make a 10 GPM pump supply 2-6 GPM. Again, the only time you see head loss through a CSV1A is when trying to get max flow from the pump.