ARAB-Abwasserreinigungsanlagen Betreiber GmbH is a joint venture owned by the two wastewater associations of Wörgl-Kirchbichl and Surrounding Areas and Brixlegg and Surrounding Areas. For many years, the company has relied on Spaans Babcock screw pumps, distributed in Austria by ACAT. In 2024, ARAB approached ACAT to request a quotation for a screw pump for Stormwater Overflow Basin II at the Söcking pumping station. At the time, the station was equipped with a Purator pump. During the inspection of the facility, it also became apparent that the existing pump, installed in 1987, was in poor condition, both in terms of the trough and the screw body.

Cost-effective solution

Refurbishment was initially considered, but following close consultation with the experts at ACAT, it was decided to purchase two new compact trough screw pumps, as refurbishment would not have been significantly cheaper than buying new pumps. “At the end of February 2025, we were awarded the contract to install and commission the two pumps, each with a diameter of 1200 mm and a flow rate of 265 litres per second,” explains Dietmar Strecker of ACAT watertech. When planning the new pumping system, the necessary VEXAT measures also had to be taken into account to ensure safe operation in potentially explosive atmospheres.

Rapid implementation

Just a few months later – at the end of September – work began on dismantling the existing pumps and installing the new systems. The new pumps were handed over and commissioned at the end of October. “The system has been running flawlessly from the very first minute, to the customer’s complete satisfaction,” Dietmar Strecker concludes.

The company also commissioned ACAT to carry out maintenance and servicing on the existing screw pumps in the wastewater treatment plant, specifically two inlet screw pumps, three screw pumps in the intermediate pumping station and two return sludge screw pumps with diameters of 1300 mm and 1100 mm respectively. “We were able to successfully complete all maintenance work in 2025. I would like to take this opportunity to thank the wastewater association and ARAB for their excellent cooperation, in particular the mayor of Kirchbichl, Herbert Rieder, ARAB’s managing director Kurt Dornhofer and technical manager Johann Kitzbichler,” says Dietmar Strecker. “This project underlines our commitment to working with our customers to deliver the best solution for every challenge.”

ARAB also views the outcome positively: “We would like to thank Dietmar Strecker of ACAT for his excellent cooperation and dedication. This enabled the project to be successfully implemented and completed,” emphasises ARAB’s managing director Kurt Dornhofer.

A strong partnership

With more than 35,000 installed screw pumps, the Dutch company Spaans Babcock is the world’s largest manufacturer of screw pumps. Every second system comes from the company, which was founded in 1897. Since 2010, ACAT has been the authorised representative in Austria and is therefore the first point of contact for this efficient and robust technology. Particularly advantageous for operators: ACAT not only sells brand new systems, but also takes care of the maintenance and servicing of existing systems.

ACAT’s product range includes wastewater pumps, return sludge pumping stations, rainwater pumping systems and industrial wastewater systems. Screw pumps are available in three configurations: in a traditional concrete trough, with a steel trough or in a prefabricated compact unit for immediate installation. “Screw pumps can be used economically within a flow rate range of 15 l/s to 12 m^³/s,” explains Dietmar Strecker. Generally, screw pumps are made of mild steel with a special epoxy coating. The required coating is selected for each application. Optionally, the screw pumps can be made of stainless steel.

Beratung ist das Fundament für eine erfolgreiche Lösung: Ing. Johann Kitzbichler, technischer Leiter der ARAB (li) und Dietmar Strecker von ACAT (re).

Long service life and easy maintenance

As Dietmar Strecker explains, screw pumps have many advantages: “A key selling point is their long service life of between 20 and 40 years. Added to this are their high operational reliability, efficiency and low wear.” A screw pump can run dry without damage and does not require a pump sump. Coarse materials such as plastic, wood, and stones do not affect the conveying process or efficiency. This distinguishes them from axial-flow or centrifugal pumps. At the same time, biological substances such as sludge flocs are handled particularly gently, for example in return sludge. The simple maintenance of screw pumps also makes them an economically and technically compelling solution for long-term operation.

ACAT has made a conscious decision to focus on this technology. “We sell screw pumps because they are currently the best product on the market for pumping wastewater and return sludge. In Spaans Babcock, we also have an experienced and internationally leading partner with whom we have been working very successfully for many years.”

“This project underlines our commitment to working with our customers to deliver the best solution for every challenge.”

Dietmar Strecker, ACAT watertech