Manufacturing professional analysing machines. Manual worker is looking at pipe. He is in reflective clothing.


KNF, specialist in specification-compliant oil-free pumps, develops, produces and distributes high-quality diaphragm pumps and systems for neutral and aggressive gases and liquids.

Interview with Stefan Steinhart, Head of Sales Export at KNF’s Product Center Gas Pumps.

Easy Engineering: A brief description of the company and its activities.

Stefan Steinhart: The KNF Group supplies oil-free pumps and pump systems suitable for handling gases, vapors and liquids from lot size 1 upwards. Our customized diaphragm pump solutions are used as equipment components in many industrial and research sectors. As benchtop devices, KNF laboratory pumps and systems support to a range of laboratory tasks on a daily basis. 

The company was founded in Germany in 1946 and since then has steadily grown into an international group of companies with 17 locations and more than 800 employees. We manufacture our dry-running, self-priming pumps at five locations in Europe and the USA. Three competence centers, located in Germany and Switzerland, are responsible for the continuous technical development of our product range. Each competence center has its own clear focus. The competence center based at the founding location in Germany focuses on gas pumps, while the one in Reiden, Switzerland, focuses on micro gas pumps, and in Sursee, just a few miles away, the engineers focus on liquid pumps. As a family-run company, we have the advantage of financial independence, which has a positive effect on our options for decision-making. Our strongest unique selling point is our flexibility. We take our customers’ needs into account at every stage in our partnership with them – all the way from technical specifications to delivery and servicing. 

E.E: What are the main areas of activity of the company?

S.S: Our purpose is to provide pump solutions for the handling of media without contamination. Due to the advantages afforded by the transfer, evacuation, compression and metering of both neutral and aggressive gases, vapors and liquids without impureness, our pumps are sought-after components for equipment used in medical technology, instrumental analysis, gas analysis, emission measurement, the hydrogen value chain, and inkjet and 3D printing systems. The low maintenance requirements of our pumps reduce the cost of ownership of the equipment over the service life of the pump. We see ourselves as a series supplier, as a partner that provides reliable support for the technical development of a device from generation to generation. However, we are also specialists in single-piece production. 

E.E: What’s the news about new products?

S.S: In the field of liquid pumps, our focus is currently on Smooth Flow, i.e. low-pulsation transfer of liquids. Our target audience includes the inkjet market: With many inks, it is particularly important that their properties are not altered by transport. Pulsations and vibrations must be avoided, and our smooth flow pump series provides gentle handling that meets these requirements. 

In the micro gas pump sector, we are working on further optimization of the size-to-power ratio. In 2016, KNF presented what was then the world’s smallest gas pump: measuring just 24.2 mm, it is half the length of a matchstick. 

The issue of efficiency is the main driver behind the trend towards dynamic operating profiles in certain applications. Our response to this trend is parametrization of the pump drive in accordance with the customer’s specific needs. Since KNF began focusing on diaphragm pump technology, we have developed an excellent level of in-house expertise in the production of motors. We design and manufacture durable, brushless motors that can’t be found anywhere else. Thanks to this in-house expertise, we have truly optimized pump head and drive, enabling the unit to handle even complex operating profiles.

We will continue to deliver on this claim with our micro gas pumps and above all, our gas pumps, which are predominantly used in stationary systems. 

In terms of the gas pump sector as a whole, we will keep striving for easy-to-service solutions. Our pumps boast low operating costs because they have long maintenance intervals and low maintenance requirements. 

E.E: What are the ranges of products?

S.S: In terms of flow rate, our gas and liquid pumps cover a range from 0.018 to 250 l/min. The maximum operating pressure of the compressors is 12 bar. The lowest vacuum we achieve with our gas pumps is 0.5 mbar abs.

E.E: At what stage is the market where you are currently active?

S.S: Due to the many advantages of our diaphragm pumps – they are oil-free, self-priming, dry-running and have a long service life – they can be used for a wide range of applications. This means that there isn’t just one single market for them. But what we can say is that our pumps are at the cutting edge of almost all the top technical trends: hydrogen, solar energy, electric batteries, climate research, environmental protection – our diaphragm pumps are used in all these forward-looking areas. This means that we are often involved right from the get-go, right when the technology is being developed at the laboratory scale, and we are also there for further scaling up to the industrial scale. 

E.E: What can you tell us about market trends?

S.S: We are seeing tremendous momentum in all areas that could contribute to a more sustainable use of the resources available to us. And the feedback we get is that that our customizable, efficient and durable pump solutions fit very well into this new way of thinking. 

E.E: What are the most innovative products marketed?

S.S: We have been able to strengthen our portfolio of oil-free ex-proof and non ex-proof vacuum pumps and compressors in an outstanding manner, particularly in the areas of emissions monitoring, gas analysis and the use of low-emission fuels such as LNG, as well as in the production and use of hydrogen. Thanks to this, combined with our in-house expertise in motors, we can also offer exclusive drive solutions that are able to deliver the dynamics that end devices require for the technology of tomorrow on the customer side. 

E.E: What estimations do you have for 2022?

S.S: In light of our very good performance in the past financial year despite the global pandemic, we are looking ahead to 2022 with optimism and confidence.