Ball Sector Valves Archives

Ball sector valves

Are used especially for dirty, abrasive, and pasty media in a variety of demanding on/off and control applications. This valve design is characterized by an extremely wide rangeability and a high flow capacity.
The special design of the ball sector valve enables the trunnions to absorb the entire force of the flowing media, which means very little actuating force needs to be generated by the pneumatic and electric drives.

Design principle of ball sector valves

The key element of these on/off and control valves is a ball sector that can rotate by 90° and is used as a flow control element. Even under the toughest operating conditions, the ball sector seals the media using a simple, replaceable seat ring in the body. One part of the ball sector serves to shut off the valve, and the other has a hole with a diameter that normally corresponds to about 80% of the nominal size of the valve. To avoid effects of thermal or mechanical stresses, the bearings and the shaft seal are mounted in swiveling bearing bushings in the body. The shaft is sealed using a self-adjusting PTFE packing with an integrated spring element that protects the bearing against media particles. Ball sector valves have centric bearings and stable trunnions. This allows the ball sector to maintain constant contact with the valve seat seal while it is rotating. Changes in the differential pressure do only have a minor influence on the constant actuation torque.

The advantages of ball sector valves

Minimal wear even with contaminated, abrasive and pasty media
Precise control over a large control range
Low actuation forces due to shaft journals with bearings
High KVS value
Robust and compact design
Long service life, low operating costs
Simple maintenance and repair
No flow deflection
No draining of paper stock due to elliptical flow geometry