Air Operated Pump Curves

[RJB32482]

Hi,
I am trying to read a pump curve for an air operated pump. The curves are for gallons per minute on the x-axis and total head on the y-axis. The lines are for air inlet psi and air consumption in SCFM. How would I design a system for pumping a number of gallons to a system under 5 psi? How can I find out air consumption? Would head just be suction head-discharge head?



Thanks

 

[Artisi]

contact the supplier / manufacturer - always seems to be the best solution.

Naresuan University
Phitsanulok
Thailand

 

[checman]

RJB32482 It is discharge head minus suction head. But remember that AOD pumps do not like pressure on the suction side. I am assuming that you are discharging into a vessel with 5 psi back pressure. If it is a common system you would need to factor line losses at your flow along with the vertical height of the discharge and add your 5 psi to get your discharge head. Plot that on the curve to get the SCFM ect.
Regards checman

 

[RJB32482]

OK I have another question on pump curve determination in general. To plot total head on the diagram what would the suction head be? Would it be just the NPSH? If not how would I calculate the suction head to obtain the total head?
Would it be:

Suction head(in)=NPSH(in)

Discharge Head(in)=[Pressure Drop of Discharge Line(psi)/density of liquid (lb/in^3)]+[backpressure(psi)/density(lb/in^3)]

Total Head(in)=Discharge head(in)-Suction Head(in)

Could someone give me the correct calculation scheme if this is incorrect? Thank You.