When Precise Vacuum Is Key: The New Diaphragm Gas Pump N 938

New KNF diaphragm gas pump for vacuum control in fuel cells, medical devices, and other applications

New KNF diaphragm gas pump for precise vacuum performance in fuel cells, medical devices, and other applications.

Whether for fuel cells, laboratory and medical applications or measurement technology, the new N 938 diaphragm gas pump is the first choice when the process requires precisely controlled vacuum performance.

Customizable Vacuum Performance Increases Efficiency

One key feature of the N 938 pump is its process-compliant vacuum performance. With its ability to adapt to changing vacuum requirements, the N 938 is designed to meet the needs of different stages of a process. Whether it is the start-up ramp, full-load operation, partial-load operation, or cool-down – the N 938 pump can deliver the required performance.


Performance-determining parameters, including motor speed, acceleration, starting curve or current limit, can be individually defined thanks to a wide range of possibilities offered by in-house developed KNF BLDC motors. The result is a pump characteristic curve tailored to the customer's specific needs. This increases productivity while also saving energy.

Precisely control of vacuum performance makes the N 938 ideal for fuel cells, medical devices and many other applications.
Precisely control of vacuum performance makes the N 938 ideal for fuel cells, medical devices and many other applications.

Reliability Meets High Performance

With flow rates of 7 to 35 l/min as a single head version or 11 to 53 l/min as a dual head standard version, the N 938 series can achieve a final vacuum of up to 140 mbar abs. Its maximum operating pressure is 1 bar g. The standard version features an aluminum pump head, EPDM diaphragm and FPM valves for reliable and efficient operation.


In addition to the parameterization options, the chemically resistant N 938 pump offers project-specific options for further customization. Available pump head materials include anodized aluminum, PPS or stainless steel, providing flexibility for various applications. The diaphragm and valves can also be made of PTFE-coated EPDM or FFPM to further enhance chemical resistance. Depending on specific requirements, the pump’s maximum media temperature can be increased up to 60° C. If required, the pump can be configured for even lower vacuum levels.

Flexibility for a Wide Range of Applications and Processes

Due to its ability to provide vacuum on demand, the N 938 is best suited due to these applications:

  • Use as a Medical Suction Pump

During surgical procedures, it is essential to dynamically aspirate blood and other body fluids to ensure clear visualization of the surgical site. The N 938 can be used as a medical suction pump to effectively remove blood during surgical procedures.

  • Durable Diaphragm Pump for Laboratory Liquid Waste

Vacuum handling of liquids is a proven technique in the laboratory. The chemical composition of sample waste and wastewater can vary widely. These problematic substances require professional disposal. The N 938 is recommended as a durable component for indirect disposal of sample waste via collection containers. When the pump head is made of anodized aluminum or PPS, constant contact with moisture and condensation does not affect the robustness of the pump. As a central vacuum pump, it can evacuate multiple collection containers simultaneously.

  • Contamination-Free Vacuum for Histology

The N 938 vacuum pump operates oil-free, a requirement in histology to keep tissue samples free from contamination. Equipped with a PPS pump head and PTFE-coated diaphragm, the N 938 also offers a material combination that is critical for solvents used in this field and is capable of safely transferring solvents from the storage tank to the processing tank via a stable vacuum.

  • Versatile Gas-Tight Feed Pump for Engine Exhaust Measurement

Whether as a feed component in engine test benches or for the Real Drive Emissions (RDE) method, the gas tightness and chemical resistance of the N 938 is a selection criterion for transferring engine exhaust gases. Another application for the N 938 in engine exhaust gas measurement is the handling of purge air to reliably calibrate the measurement system for a subsequent analysis.

  • Powerful Vacuum for Vacuum Gripping Systems and Vacuum Lift

Vacuum lifters and grippers are another area of application for the N 938. It is necessary to have a targeted and reliable vacuum so that the suction pressure holds the object securely during the respective movement of the gripper or lifter.