Working Principle of an AODD Pump

AODD stands for Air-Operated Double-Diaphragm. An AODD pump uses compressed air or nitrogen to alternately move two flexible diaphragms, creating suction and discharge strokes that transfer liquid through the pump. SANDPIPER describes this as a reciprocating pumping process controlled by a main air valve, pilot valve and check valves.

How Does an AODD Pump Work?

The working cycle can be understood in six basic steps:

1. Compressed Air Enters the Pump

Compressed air enters the main directional air valve. The valve directs the compressed air into one of the pump's air chambers.

The air pressure acts across the inner surface of one diaphragm, pushing it toward the liquid chamber. At the same time, air is exhausted from the opposite diaphragm chamber.

2. One Diaphragm Performs the Discharge Stroke

The two diaphragms are connected by a common rod, so movement of one diaphragm causes the other to move in the opposite direction.

As one diaphragm moves inward, it reduces the volume of its liquid chamber and pushes the liquid toward the discharge outlet.

The check valves control the direction of fluid flow.

3. The Opposite Diaphragm Creates Suction

At the same time, the second diaphragm moves outward.

This increases the volume of its liquid chamber and lowers the pressure inside it. The resulting pressure difference allows atmospheric pressure to push liquid through the suction pipe and into the pump chamber.

4. The Pilot Valve Triggers the Next Stroke

As the diaphragm reaches the end of its stroke, its movement actuates the pilot valve.

The pilot valve sends a signal that shifts the main directional air valve, redirecting compressed air to the opposite air chamber.

5. The Diaphragms Reverse Direction

The compressed air now pushes the opposite diaphragm.

The diaphragm that was previously performing suction begins the discharge stroke, while the other diaphragm begins the suction stroke.

6. The Cycle Repeats

The alternating movement continues:

Compressed Air → Diaphragm Movement → Suction → Discharge → Air-Valve Shift → Reverse Stroke → Repeat

This reciprocating action produces continuous fluid transfer.

Contact Details :- APOORVA VALVES | Industrial Pump & Valves

Mob No :-              9810057364

Location :-            NOIDA

E-Mail :-                rakesh@apoorvavalves.com

Website :-             www.apoorvavalves.com

YouTube :-           https://youtu.be/RihIfc-ayuY?si=7rOpbYeWRuIpvzg1