Application Success


Make: Voith
Industry: Pulp & Paper


A paper recycling mill had a vertical pulper that was leaking continuously for years. Pulpers are notoriously difficult to seal due to extreme shaft movement, along with abrasive materials in the tub.

Multiple sealing solutions were attempted, including a variety of packing types, but none lasted more than three weeks. The leakage was causing housekeeping and safety issues and required constant oil changes in the gearbox below due to water ingress.


An Inpro/Seal® Air Mizer® shaft seal was installed in April 2016. The Air Mizer seal is a non-contacting, non-wearing shaft seal that utilizes a positive air purge to permanently protect against product loss and contamination. Its unique zero-maintenance design can fully articulate to handle angular, radial and axial shaft movement simultaneously.


After installation, the Air Mizer shaft seal stopped all water and paper stock leakage from the pulper tub. The area below the pulper is now completely dry, making it safe for personnel to perform inspections and preventative maintenance checks. In addition, because there is no leakage, frequent gearbox oil changes have been eliminated.

Vertical recycle paper pulper drive shaft
Vertical recycle paper pulper drive shaft with Air Mizer shaft seal
Air Mizer Food Grade shaft seal

Maintenance-Free Shaft Sealing

Inpro/Seal Air Mizer shaft seals provide permanent protection against product loss and contamination on industrial process equipment. With a unique, non-wearing design, Air Mizer seals are maintenance-free and constructed to last the lifetime of your equipment.

Read More

Air Mizer Smooth Bore shaft seal

Ready to Get Started?

Count on us to improve reliability and process efficiency within your facility. Our experienced sales and engineering team can design custom engineered bearing protection or shaft sealing solutions to fit the exact requirements of your equipment and operating environment.

Contact a Rep