KSB Aktiengesellschaft successfully tested a high-performance gate valve at the Großkraftwerk Mannheim (GKM) power plant as part of the 725 HWTII project.
The gate valve is designed for a new generation of fossil-fuelled power stations with improved efficiency achieved by using steam temperatures above 700°C. Two prototypes from the ZTS valve range have successfully completed a test period of almost two years, continuously operating at 725°C.
Developed at KSB’s Pegnitz site, the gate valve’s basic design has been in use for decades in a huge number of power plants. It features a billet-forged body, a split wedge serving as a shut-off element and a pressure seal bonnet. The design has been optimised to match the power plant’s specific operating conditions. For example, the new design features a spherical body that helps to reduce thermal stresses. Extended yoke arms protect actuators from the potentially negative effects of the hot fluid. The main valve components are made of nickel base alloy 617 B. Positive experience has already been gained with this material during a previous research project carried out at the GKM plant.
