Power plants ASME N-stamp

Shut-off valves – what counts

We would like to illustrate the things that set high-quality butterfly valves apart from the rest of the market, taking the example of the classic VAG EKN® Butterfly Valve in the cooling circuit.

The following design details guarantee durability and functionality according to the VAG standard:

1. Coating

Whether drinking water, water with strongly abrasive contents or salt water: The right coating protects the components in the interior of the valve against corrosion and damage. The selection of the surface coating is partly decisive for the service life of a valve.

 2. Seat weld deposit

Unlike the bolted-on or rolled-in sealing systems, weld overlays bonded permanently to the body material offer a sealing seat that is absolutely resistant to infiltration by corrosion. Corrosion and the associated detachment from the valve body are thus fully excluded.

3. Safe connection

Only a secure connection between the valve shaft and the disk guarantees a long service life of shut-off valves. It prevents play arising in the shaft connection, which can lead to the loss of water, a high resistance and thus and increase in energy consumption.

4. Shaft seal

To prevent corrosion and dirt, the sealing of the shaft bearing with multiple O-rings is indispensable. The seal prevents the penetration of water and abrasive particles into the bearing and thus also increased wear of valve shafts and bearing bushes. 

5. Circumferential seal

To prevent seals on the disk being pulled out, VAG uses exclusively seals with a pronounced profile, sufficient hardness and shearing resistance. VAG seals are also usable at high gap flow velocities and support the sealing effect irrespective of the direction of flow.