Usage of AVK butterfly valves with fixed liner

Centric butterfly valves with fixed liner – wafer, semi lug, full lug and double flanged

Our fixed liner butterfly valves are among the very few of its kind and offer superior advantages.

An outstanding seating concept is the heart of the valve. The rubber is vulcanized directly on the valve body forming a permanent bond with an optimal rubber shore hardness. Consequently, there is no risk of deformation or dislocation of the liner. The valves are therefore suitable even under vacuum conditions.

The disc has a profiled sealing edge which requires minimal deformation of the liner to achieve a tight sealing. This gives less wear of the liner and low operating torques.

AVK series 75 centric butterfly valve with fixed liner
Series 75 butterfly valve from AVK

Design features of AVK centric butterfly valve with fixed liner

  • Fixed liner design with vulcanized liner gives:
    • no tolerance problems between body and liner
    • no risk of deformation or dislocation, thus suitable under vacuum conditions
    • optimum shore hardness of the rubber
  • AVK's own rubber liner with excellent ability to regain shape after compression
  • Disc with profiled sealing edge gives less wear of liner
  • Low operating torques due to fixed liner, profiled disc and shaft bearings
  • Streamlined disc prevents turbulence, pressure drops and valve vibration

Wafer, semi lug, full lug, double flanged butterfly valve - with any type of actuation

  • Dimensions: DN40-2000
  • Valve function: Isolating or regulating
  • Actuation: Lever, wormgear, pneumatic and electrical actuators
  • Materials: Shaft of stainless or duplex steel, disc of stainless or duplex steel or rilsan coated ductile iron, and liner of EPDM (for use with drinking water or high temperatures) or NBR 

Where are centric butterfly valves with fixed liner used?

Fixed liner butterfly valves can be used under vacuum conditions as there is no movement and wear of the liner. Furthermore, the fixed liner valve is suitable for high flow velocities and high operating cycles e.g. open/close every few seconds. Fixed liner butterfly valves are typically used above ground, but the double flanged types are also suitable for below ground installations.

The centric butterfly valve with fixed liner can be used in a number of applications within water and wastewater treatment, fire protection and gas supply.

  • Water: water treatment, water distribution, pumping installations, water transmission and HVAC
  • Wastewater treatment: aeration systems, clean wastewater, filter installations, pumping installations and membrane installations
  • Gas supply: natural gas and flare gas
Video displaying the features and installation of the centric butterfly valve fixed liner - thumbnail

Animation

Centric butterfly valves with fixed liner

Animation about the features of our butterfly valves series 75.

Case

Improved water environment and efficiency

The Wastewater Treatment Plant in Czajka, Poland, has been modernised to improve both efficieny and water environment in Warsaw. AVK has delivered 1,200 valves for the project.