Ball sector valves by Schubert & Salzer

Ball Sector Valves

The valve for abrasive and slurry on/off and control applications.

Ball sector valves from Schubert & Salzer

The ball sector valves of Schubert & Salzer 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.

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Long service lives with abrasive media and maximum precision over a large control range are the speciality of Schubert & Salzer's ball sector valves.

Design principle 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.

Design principle ball sector valves

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

Wear resistance

Ball sector valves are frequently compared to rotary globe valves due to their design. The key difference between ball sector valves and rotary globe valves is the type of bearing. In general, rotary globe valves are equipped with an eccentric bearing. This causes the shut-off element to lift off the valve seat when the valve is opened. The result is that the sealing surfaces are continuously exposed to abrasive media when the valve is partially or fully open. For suspensions containing solid particles, the medium can get between the ball or plug and the seal ring, damage the surfaces, and cause leaks. Ball sector valves have centric bearings, which means the ball sector does not loose contact with the valve seat when rotating. Deposits on the surface of the ball sector are wiped off by the seat ring, and solids cannot get stuck between the valve seat ring and ball sector when the valve is closed.

Wear resistance ball sector valves

Life span

The intelligent design of the seals in our ball sector valves, in combination with various materials and surface treatments for the ball sector and valve seat, form the basis for long life spans and reliable operation, especially in applications with abrasive, highly viscous, or fibrous media.

Life span ball sector valves
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