Air operated diaphragm pumps (AOD pumps) are versatile, reliable pumps used across numerous industries for transferring various fluids. Their simple design, self-priming capability, and ability to handle viscous or abrasive liquids make them popular in chemical processing, wastewater treatment, food production, and more. This guide will walk you through proper operation and maintenance procedures.

Understanding Your AOD Pump Components

Before operating your diaphragm pump, familiarize yourself with its key parts:

• Air motor section: Contains the air valve that controls reciprocating action

• Diaphragms: Flexible membranes that create pumping action (typically two)

• Pump chambers: Where fluid is drawn in and expelled

• Ball valves: Check valves that control fluid direction (usually four)

• Air inlet: Connection for compressed air supply

• Inlet/outlet ports: For fluid intake and discharge

Step-by-Step Operation Guide

1. Pre-Operation Checks

• Inspect the pump: Look for damage, loose bolts, or worn components

• Verify diaphragm condition: Check for cracks, tears, or excessive wear

• Confirm ball valves move freely: They should rattle when shaken

• Check air supply: Ensure you have adequate clean, dry compressed air (typically 20-120 PSI)

2. Installation and Setup

1. Mount the pump securely using appropriate brackets or fasteners

2. Connect fluid lines:

   • Use proper hose/pipe size matching pump ports

   • Install suction strainer if pumping liquids with particulates

3. Connect air supply:

   • Use appropriate air hose (typically 3/8" or 1/2")

   • Install air filter/regulator/lubricator (FRL) unit if recommended

4. Prime the pump (for some applications):

   • Fill chambers with liquid if dry-start could damage diaphragms

3. Starting the Pump

1. Open fluid supply valve fully

2. Adjust air regulator to lowest pressure setting

3. Open air supply valve gradually

4. Observe flow and adjust air pressure to achieve desired flow rate

5. Check for proper operation:

   • Listen for steady reciprocating rhythm

   • Watch for consistent discharge flow

   • Monitor for unusual vibrations

4. Shutdown Procedure

1. Close fluid supply valve

2. Shut off air supply

3. Drain pump if needed (especially for freezing conditions or corrosive liquids)

4. Clean exterior if pumping hazardous materials

Performance Adjustment

• To increase flow rate: Raise air pressure (within pump's rated limits)

• To decrease flow rate: Lower air pressure or install flow control valve

• For thicker fluids: Reduce pump speed (lower air pressure) to prevent ball valve sticking

Maintenance Tips

• Daily: Check for air leaks, unusual noises, and proper flow

• Weekly: Inspect diaphragms and ball valves

• Monthly: Check all bolts and fittings for tightness

• As needed: Replace worn diaphragms, balls, or seats

Troubleshooting Common Issues

Safety Considerations

• Always wear appropriate PPE when operating or servicing

• Never exceed maximum rated air pressure

• Lock out/tag out air supply before maintenance

• Use proper ventilation when pumping volatile liquids

• Follow all manufacturer safety guidelines

By following these operational procedures and maintenance practices, your air operated diaphragm pump will provide reliable service with minimal downtime. Always consult your specific pump's manual for model-specific instructions and specifications.