Reading the AODD Pump Performance Curve — Antlia Engineering Works Mumbai

Reading the Air Operated Double Diaphragm Pump Performance Curve

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Audio version — Practical Guide to Installing and Operating an AODD Pump

At Antlia, we offer a variety of AODD pumps across our range. In this guide, we focus on the AOD 40 model as a worked example — but the method for reading a performance curve applies to all AODD pump models. Understanding how to read a performance curve allows you to select the right pump and correctly size your compressed air supply for any application.

Antlia AOD 40 — Key Specifications

About the AOD 40 Performance Curve

The performance curve for the AOD 40 model shows the required inlet air pressure to pump a specific volume of liquid at a specific discharge pressure. The pump is capable of the following:

Max Flow: 140 LPM
Max Pressure: 7 bar
Port Size: 40mm (1½")
Fluids: Acids, Solvents, Paints, Lubricants & More

The performance curve may look complicated at first glance — but with a little explanation, it is straightforward to use. Let's break down each component of the graph.

Understanding the Graph Axes

The Three Key Elements of the Performance Curve

X-Axis (Horizontal)

The bottom horizontal axis shows the discharge of liquid in litres per minute (LPM). This is the flow rate output of the pump at any given operating condition.

Y-Axis (Vertical, Red)

The left vertical axis shows the air pressure in bar — measured from 0 to 7 bar. This is the inlet air pressure required to achieve a given flow rate at a given discharge pressure.

Black Point (Reference)

The black point is the air consumption reference point — it shows the pump's air consumption in both m³/hr and SCFM (Standard Cubic Feet per Minute) at any operating condition.

Blue Lines: The solid blue lines on the graph represent different discharge pressure levels. Each line shows the relationship between flow rate (X) and required inlet air pressure (Y) at that specific discharge pressure.
Worked Example

How to Read the Curve — Step-by-Step Example

Let's work through a practical example: We need 60 litres per minute at 4 bar discharge pressure. What inlet air pressure and air consumption (SCFM) do we need?

1

Find 4 bar on the Y-axis. Place your pointer on the 4 bar line on the left-hand (red) Y-axis. This is your required discharge pressure.

2

Find 60 LPM on the X-axis. Locate 60 litres per minute on the bottom horizontal X-axis. This is your required flow rate.

3

Find the intersection point. Draw a vertical line upward from 60 LPM and a horizontal line across from 4 bar. Find where these two lines meet on the nearest solid blue curve on the graph.

4

Read the inlet air pressure. Follow the closest solid blue line up to the left until it meets the Y-axis. This is the inlet air pressure required. In this case: 5 bar inlet pressure.

5

Read the air consumption. Trace the pointer along the nearest blue line from the intersection point to the connected green box (via the black reference point). This gives the required air consumption. In this case: 14 SCFM.

✅ Result: To achieve 60 LPM at 4 bar discharge pressure — you need 5 bar inlet pressure at 14 SCFM air consumption.
Practical Value: Looking at the performance curve tells you exactly what to expect from the pump — including the compressed air line size and compressor capacity required. It is the most reliable way to evaluate whether a pump model is the right fit for your application.
Why Performance Curves Matter

Using the Performance Curve to Select the Right Pump

The performance curve allows you to calculate the air consumption and pressure required to move a specific volume of liquid at a specific discharge pressure — for every operating point the pump can run at.

This is critical for:

  • Verifying the pump can deliver your required flow rate at your system's back pressure
  • Sizing your air compressor and FRL unit correctly for the application
  • Selecting the right pump model from the range (½", 1", 1½", 2" etc.)
  • Avoiding over-pressurising by knowing the exact air pressure needed
  • Estimating operating costs based on air consumption (SCFM)

Need help selecting the right Antlia AODD pump for your flow and pressure requirements?

Share your required flow rate (LPM) and discharge pressure (bar) with our engineers — we will match you to the right AOD pump model from our range and provide the performance curve.

Get Free Pump Selection Help Call +91 9819395995

Frequently Asked Questions

What does the X-axis of an AODD pump performance curve represent?

The X-axis (bottom horizontal axis) shows the discharge of liquid or fluid in litres per minute (LPM) — the flow rate output of the pump at any given operating condition.

What does the Y-axis of an AODD pump performance curve represent?

The Y-axis (vertical axis, shown in red) shows the air pressure in bar — measured from 0 to 7 bar. It represents the inlet air pressure required to achieve a specific flow rate at a specific discharge pressure.

What is the black point on an AODD pump performance curve?

The black point is a reference point that shows the air consumption of the pump — measured in both cubic metres per hour (m³/hr) and standard cubic feet per minute (SCFM). It is used to determine how much compressed air the pump consumes at any given operating condition.

How do you use an AODD pump performance curve to find the required inlet pressure?

Identify your required flow rate on the X-axis and your required discharge pressure on the Y-axis. Find the intersection on the nearest blue curve, then follow the curve to the Y-axis to read the required inlet air pressure. Trace to the black point to read the air consumption in SCFM.