Happy to help !
Depending on the application 5,3, or 2HP would work.
Will show Model 516 as example;
* produces 3 GPM @ 713 RPM, 2HP when pressure is set to 1000 psi.
* produces 3 GPM @ 713 RPM, 3HP when pressure is set to 1500 psi.
* produces 4 GPM @ 950 RPM, 3HP when pressure is set to 1100 psi.
* produces 4.5GPM @ 1070 RPM, 3HP when pressure is set to 1000 psi.
* produces 5 GPM @ 1200 RPM, 3HP when pressure is set to 900 psi.
* produces 4 GPM @ 950 RPM, 5HP when pressure is set to 1850 psi.
* produces 4.5GPM @ 1070 RPM, 5HP when pressure is set to 1650 psi.
* produces 5 GPM @ 1200 RPM, 5HP when pressure is set to 1500 psi.
Re; pressure & nozzle size;
Pressure is created by restriction of the pumped water flow through the spray nozzle(s).
No nozzle(s) or oversized nozzle(s) = Reduced or no pressure.
Pressure is controlled by a pressure regulator (or unloader).
Water delivered from the pump, which is not needed to meet a set pressure, is bypassed through the pressure regulator (or unloader).
Note water flow & size nozzle(s).
Water flow through a nozzle with vary with pressure, refer to Nozzle Performance Chart.
examples;
#5 nozzle passes 2.5 GPM when pressure is set to 1000 PSI.
#5 nozzle passes 5 GPM when pressure is set to 4000 PSI.
#6 nozzle passes 3 GPM when pressure is set to 1000 PSI.
#6 nozzle passes 6 GPM when pressure is set to 4000 PSI.
Insure correct Motor RPM and pulleys.
Electric Motor RPM, Electric motor pulley diameter, & Pump pulley diameter determine Pump RPM.
Pump RPM determines its flow produced.
Helpful tutorial here pertaining to nozzles, HP, & pulleys;
arimitsupumps.com
* click "technical tips"
Happy to help !
Greg @ Arimitsu Pumps