Sheep

Hi, I am trying to estimate the flow rate of a closed loop hydraulic system. I know the pump speed, static pressure and pump pressure/flow curve in set rpm. I assume that the liquid is water. Is this valid method to estimate the flow rate? If i can measure the pressure in the pipe with pressure gauge i would convert that to head and compare it to the pump head/flow curve? For example: Pressure in pipe(measured with pressure gauge):3 bar converts to 30,6 m of head. total head would be 30,6m ? Now if i read the flow rate from pump curve i should get some kind of estimate of the flow rate?