GasFree Valve™

Reduced defoamer usage, improved air removal technology

As the pulp mat dries, the drainage channels of a vacuum washer drum fill with air. With a traditional valve, this air is forced down the dropleg, reducing vacuum and increasing air entrainment. The patented GasFree™* Valve segregates this air from the dropleg flow, redirecting it back to the hood or collection system. Mills facing high defoamer consumption can utilize this upgrade to save chemical costs and reduce air entrainment. Additionally, the all-stainless construction makes the GasFree Valve a very durable design.

Our patented opening in the GasFree Valve allows for the separation of the air and filtrate. The air is piped back to the hood (or atmosphere) while the filtrate is piped to the filtrate tank. Additionally, the DrumSafe™* surface is a bolt-on feature which protects the stainless valve body and drum from contact. This upgrade is available for both conical and cylindrical valves.



  • Reduced defoamer usage
  • Increased dropleg vacuum increases effective filtrate tank capacity
  • Increased drainage rate
  • Improved mat formation

* Trademark of the ANDRITZ GROUP. For information regarding ownership and countries of registration, please visit