Customer: Community Boxberg
Products: 2 x VAG EKN® Butterfly Valves DN 2000 PN 6 incl. 1 VAG hydraulic brake-and-lift unit (as pump protection device in the main cooling water system) + safety interlock according to UVV
In Boxberg, a community in Germany’s state of Saxony, the lignite-fired Unit R of the power plant with an electric power output of 675 MW was commissioned in October 2012.
For this newly built unit VAG supplied a number of valves including VAG EKN® and VAG CEREX® Butterfly Valves, VAG RIKO® Plunger Valves, VAG SKR Slanted Seat Tilting Disk Check Valves as well as VAG EKO®plus Gate Valves.
To protect the main cooling water pump from cooling water pressure surges during controlled shut-down but also in the event of a quick shut-down, two VAG EKN® Butterfly Valves DN 2000 with a hydraulic brake-and-lift unit were installed downstream of this pump.
The design of the butterfly valve has been adapted to the pressure surge calculations of the main cooling water system to be able to resist all conditions present in the system.
The VAG EKN® Butterfly Valve must be able to shut off mass flow rates of 10.28 m³/s during a controlled closing procedure.
By way of a two-step closing characteristic, the disk of the butterfly valve is moved from a 90°opening to a 20° opening in nine seconds. It takes another 30 seconds until the valve is fully closed. The opening time for this unit is 45 seconds.
The kinetic energy needed to close the butterfly valve is stored in the three-tonne drop weight.