Diaphragm pumps, also known as membrane pumps, diaphragm pumps are positive displacement pumps that utilize a flexible diaphragm to move fluids. Their robust design and ability to handle a wide range of fluids make them indispensable in various industrial and domestic applications.   

How They Work:

The core of a diaphragm pump is the flexible diaphragm, typically made of rubber, thermoplastic elastomer (TPE), or Teflon (PTFE). This diaphragm is connected to a reciprocating mechanism, often driven by compressed air (air-operated double-diaphragm pumps or AODD), an electric motor, or a hydraulic system.   

The pumping action occurs in a cyclical manner:

Suction Stroke: As the diaphragm retracts, it increases the volume of the pumping chamber, creating a vacuum. This vacuum pulls fluid into the chamber through an inlet valve.
Discharge Stroke: As the diaphragm moves forward, it decreases the volume of the pumping chamber, pressurizing the fluid. This pressure forces the fluid out through an outlet valve.   
Two check valves, one at the inlet and one at the outlet, ensure unidirectional flow. These valves prevent backflow and maintain the pump's efficiency.   

Key Advantages:

Handling Diverse Fluids: Diaphragm pumps can handle a wide range of fluids, including corrosive chemicals, abrasive slurries, viscous liquids, and even shear-sensitive fluids. This versatility stems from the diaphragm's ability to isolate the fluid from the pump's internal mechanisms.   
Dry-Running Capability: Unlike many other pump types, diaphragm pumps can run dry without damage. This makes them ideal for applications where the fluid supply may be intermittent or unreliable.
Self-Priming: Diaphragm pumps are typically self-priming, meaning they can draw fluid from below the pump's inlet without needing to be filled with liquid beforehand.
Leak-Free Operation: The sealed diaphragm design minimizes the risk of leaks, making them suitable for handling hazardous or environmentally sensitive fluids.
Variable Flow and Pressure: The flow rate and pressure of a diaphragm pump can be easily adjusted by controlling the speed of the reciprocating mechanism or the air pressure in AODD pumps.   
Simple Maintenance: Diaphragm pumps generally have a simple design, making them relatively easy to maintain and repair.