News & Announcements


New Pump Rotor Design Released

Posted August 30, 2022

At ONLINE we are committed to a culture of both collaboration and continuous improvement. Each change in our equipment is designed to improve ease of use and performance. In some cases, change is directly related to concerns raised by our partners in the diagnostic culture media production industry. Recently, some of our colleagues raised questions about the buildup of silicone tubing particulate in the pump heads. Our engineering team took up the question, and the study has resulted in the design of a new rotor assembly for our proprietary pumps. 

The center hub, or half-shaft, rotor design maintains the offset roller design but reduces friction by eliminating the exposed roller shafts that exists in the full shaft design. As a result, tubing wear and the consequent silicone particulate is reduced as well. In tests at a partner site, the new design was shown to increase process capability across the life of the tubing as well.

The new center hub rotor is a drop-in replacement for existing ONLINE rotors. It eliminates the need for grip rings, reducing the maintenance requirements of the pump heads. It also reduces or eliminates the need for lubrication on the rollers, reducing pump setup time.

We are pleased to be able to make the new rotor design available to our customers for both the primary and additive pump heads. For more details about the new rotor design, you can download the PDF below, or you email us at

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New center hub rotor assembly. Primary pump assembly shown.