To find out how much compressed air you need to run an Air Operated Diaphragm (AOD) pump, first learn how to read an AOD Pump curve correctly.

how to read aod pump curve

As one of the safest and easy-to-operate pumps, AOD pumps are used where electricity isn’t available, or in explosive or flammable areas.

AOD pumps are self-priming and have a vastly different pump performance curve than those of centrifugal pumps’.

Understanding the pump curve enable you to specify the AOD pump for optimum life and performance, thus reducing any unneeded downtime.

What is in an AOD pump curve?

In this example, we’ll use Graco Husky 307 AOD pump with PTFE diaphragms.

graco husky 307 pump curve

On the vertical axis (Y axis), it indicates the discharge pressure, which is measured in psi (bar) or feet (metres). This axis also indicates the inlet air pressure.

On the horizontal axis (X axis), it specifies the fluid flow rate, which is measured in gallon per minute (gpm) or litre per minute (lpm).

The darker lines shown above indicate the air consumption, which is measured in standard cubic feet per minute (scfm) or metre cube per minute (m3/min).

How to find air consumption and air pressure?

Let’s imagine that we need to supply 3 gpm (11.4 lpm) of fluid flow at 50 psi (3.5 bar) or 115 feet (35 metres) discharge head pressure.

graco husky 307 pump curve 3gm 50psi

By travelling up the solid curve, it indicates that 70 psi (4.9 bar) or 160 feet (48.8 metres) of inlet air pressure is needed. The air consumption required is 3 scfm (0.084 m3/min).


Have questions about AOD pump curves? Let us know in the comment section below.