- #1
TheRedDevil18
- 408
- 1
Hi all, I have a positive displacement (diaphragm) pump that I am looking to use to supply spray nozzles. The pump has a max pressure rating of 69 bar at 30.6 L/min (1450 rpm). I however want my nozzles to spray at 15 bar pressure and from the nozzle performance data sheet that equates to 0.68 L/min per nozzle. If I have a total of 4 nozzles that gives a total flowrate of 4*0.68 = 2.73 L/min.
I know that to vary the flow in a PD pump, you vary the rpm of the motor, however my rpm is fixed at 1430 rpm and from the pump curve that's about 30 L/min.
My questions: (Pump datasheet is attached below)
So I need to shunt the excess 27.27 L/min back to the tank through a relief valve ?
I'm a bit confused on the pressure output. From my understanding, a PD pump is like a plunger or syringe. If I put my thumb on the output, the force I need to push down increases the more I close the output. Which means the pressure seen by the pump is dependent on the load or in my case nozzle resistance.
So would the pressure output on the pump vary depending on the nozzle ?, or would it still push 69 bar regardless ?
I know that to vary the flow in a PD pump, you vary the rpm of the motor, however my rpm is fixed at 1430 rpm and from the pump curve that's about 30 L/min.
My questions: (Pump datasheet is attached below)
So I need to shunt the excess 27.27 L/min back to the tank through a relief valve ?
I'm a bit confused on the pressure output. From my understanding, a PD pump is like a plunger or syringe. If I put my thumb on the output, the force I need to push down increases the more I close the output. Which means the pressure seen by the pump is dependent on the load or in my case nozzle resistance.
So would the pressure output on the pump vary depending on the nozzle ?, or would it still push 69 bar regardless ?