Diaphragm liquid pumps are positive displacement pumps that use a flexible diaphragm to move fluid. There are several types of diaphragm pumps, each with its own design and application advantages. Here are some of the most common types:

 

1. **Membrane Diaphragm Pumps**:

   - These pumps use a flexible membrane instead of a diaphragm. They are often used for corrosive or aggressive fluids and are suitable for high-purity applications.

 

2. **Air-Operated Diaphragm Pumps (AODP)**:

   - These pumps are actuated by compressed air. They have a simple design with no valves or electric motors, making them ideal for hazardous environments or where electrical components are not permitted.

   - There are two main types of AODP:

     - **Double-Acting Air-Operated Diaphragm Pumps**: Have two diaphragms and two air inlets, allowing for continuous flow.

     - **Single-Acting Air-Operated Diaphragm Pumps**: Have one diaphragm and one air inlet, with flow that stops when the air supply is cut off.

 

3. **Diaphragm Metering Pumps**:

   - These pumps are designed for precise and consistent dosing of fluids. They can handle a wide range of viscosities and are often used in chemical processing, pharmaceuticals, and water treatment.

 

4. **Peristaltic Pumps**:

   - While not a traditional diaphragm pump, peristaltic pumps use a flexible tube that is compressed and released to move fluid. The action is similar to a diaphragm pump in terms of positive displacement, and they can be considered a type of diaphragm pump due to their function.

 

5. **Bellow Diaphragm Pumps**:

   - These pumps use a flexible bellows instead of a diaphragm to move fluid. They are often used in high-pressure applications and can handle fluids with a high viscosity.

 

6. **Crankcase Diaphragm Pumps**:

   - In these pumps, the diaphragm is mounted in a cranked casing, which provides a larger area for the diaphragm to move, allowing for high flows at low pressures.

 

7. **Solenoid-Operated Diaphragm Pumps**:

   - These pumps are electrically operated and use a solenoid to control the flow of fluid. They are compact and can be easily integrated into automated systems.

 

Each type of diaphragm pump has its own set of features and benefits, and the choice of pump depends on the specific requirements of the application, such as the type of fluid being pumped, flow rate, pressure, viscosity, and the presence of solids or chemicals.