At the heart of KNF pumps is the diaphragm, which moves media with precision, prevents contamination and provides excellent sealing. When handling gaseous media, diaphragm pumps are resistant to moisture and condensate. Used as liquid pumps, they are self-priming and dry run safe. These characteristics combine to make diaphragm pumps both versatile and reliable.

Low Maintenance Requirements

All KNF diaphragm pumps are designed without moving seals to eliminate friction and leakage for a long, low-maintenance service life. This, together with their low noise emissions, makes diaphragm pumps particularly suitable for medical or laboratory applications, for example, and underscores their vital role in demanding environments.


Each KNF series model can be customized to meet individual requirements. The use of different materials for the wetted parts of the diaphragm pumps ensures chemical compatibility and resistance to moisture, condensation and chemicals.

Energy Efficiency

As we continue to innovate with the dedication to precision for which KNF is known, we are also constantly working to offer our customers even greater flexibility – for example, by making even more of our diaphragm pumps digitally customizable.

Other Benefits of Diaphragm Pump Technology Include:

Precision transfer: Provides accurate transfer of liquids and gases.
Contamination prevention: Oil-free operation and gentle media handling maintain product integrity and prevent contamination.
Excellent sealing: Minimizes the risk of leakage.
Self-priming & dry-run safety: Ideal for liquid applications.
Moisture resistance: Can operate with wet or humid gases and condensate.
Quiet operation: Produces low noise levels suitable for noise-sensitive environments.
Versatility & reliability: Proven in a wide range of industrial and research applications.

How a Diaphragm Pump Works

Diaphragm pumps operate as positive displacement pumps in which a drive mechanism causes a connecting rod to reciprocate, moving an elastomer diaphragm up and down. This pumping action, in which the medium is drawn in through the inlet valve on the downward stroke and then discharged through the outlet valve on the upward stroke, provides an efficient transfer of gases and liquids. In liquid applications, self-priming and the ability to safely run dry are key features of KNF diaphragm pumps.

Double Diaphragm Technology for Demanding Applications

The introduction of the double diaphragm was a significant milestone in the history of KNF and provides a reliable and safe solution for pumping valuable or explosive substances in chemical or pharmaceutical applications or for use in potentially explosive environments. For maximum safety, these diaphragm pumps feature both a working diaphragm and a safety backup diaphragm to separate the compression chamber from the drive. The space between the working diaphragm and the safety diaphragm also prevents gas leakage in the unlikely event of a working diaphragm failure.

Expert Diaphragm Support

KNF products and solutions utilize a variety of diaphragms tailored to specific applications, including flat, molded, structured, zone, convoluted and oval diaphragms. We are committed to helping our customers find the ideal diaphragm to ensure optimum performance and maximize the benefits of the diaphragm pump operating principle.

In addition, the size and performance parameters of our diaphragm gas and liquid pumps can be customized with a range of motor types, electrical components and mechanical options to meet the needs of any application, including the selection of complementary diaphragm pump accessories.

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