Diaphragm Vacuum Pump

A diaphragm vacuum pump is a type of diaphragm pump designed to create vacuum without using oil. It works by flexing a diaphragm to move air through the pump chamber, producing clean, dry vacuum for laboratory and industrial applications.

Because diaphragm vacuum pumps operate without oil, they require minimal maintenance and eliminate the risk of oil contamination. They are commonly used for filtration, degassing, rotary evaporation, vacuum drying, aspiration systems, desiccators, and vacuum ovens.

Typical performance:

• Ultimate vacuum: 75 to 150 mbar
• Flow rates up to 8.3 m³/h (4.87 CFM)

A diaphragm pump creates vacuum through the repeated movement of a flexible diaphragm. As the diaphragm moves, the volume inside the pump chamber changes, drawing air in and expelling it through outlet valves.

This oil-free pumping principle provides reliable vacuum generation while helping maintain sample purity and reducing maintenance requirements.

Learn more: How Do Diaphragm Vacuum Pumps Work?

Welch diaphragm vacuum pumps are designed for clean vacuum applications where oil-free operation is critical.

Common diaphragm pump uses include:

• Laboratory filtration
• Solvent evaporation and rotary evaporation
• Vacuum ovens and desiccators
• Degassing liquids
• Aspiration systems
• Analytical instruments
• Sample preparation
• Chemical processing applications

Standard Duty Diaphragm Pumps

Reliable oil-free vacuum pumps for routine laboratory applications including filtration, aspiration, and sample preparation.

Chemical Duty Diaphragm Pumps

Designed for applications involving aggressive chemicals and solvent vapors. Chemically resistant materials help improve durability and process reliability.

Laboratory Vacuum Systems

Integrated vacuum systems optimized for rotary evaporation, gel drying, filtration, and other laboratory workflows.

To learn more about Dry Fast products, take a look at the Dry fast Catalog on our knowledge base page.

• Oil-free operation
• Low maintenance requirements
• Clean, contamination-free vacuum
• High chemical resistance
• Reliable continuous-duty performance
• Lower cost of ownership compared with oil-sealed alternatives