In conventional power plants, such as coal-fired or gas-fired power plants, water is heated in the steam generator by combustion. The resulting steam is used to drive turbines at very high pressure and temperature. A generator is coupled to these turbines, which converts the mechanical power into electrical power.
For this purpose, the KLINGER Schöneberg ball valve with welding ends type INTEC K211-S-HT DN40 PN160 is used. The ball valve has been specially designed for the application of venting and draining superheated steam in conventional power plants with process conditions of 325°C and an operating pressure of 27.5 bar. To protect the automation unit (consisting of single-acting pneumatic actuator and Topworx limit switch box) from excessive temperature, mounting bridge and two stem extensions with total height of approx. 300 mm were built in combination.
The variant used is a trunnion-mounted metal-seated ball valve with both side spring loaded seat rings. Ball and seats are made of Superduplex material (1.4980) and coated with nickel-based hard alloy (SC4) by thermal spraying with subsequent melting to produce a non-porous hard material. This results in the highest resistance of the ball-seat system during thermal cycling.
This ensures a reliable tight seal and maintenance-free operation even in applications with high operating cycles, which is crucial in power plants.