Cause Analysis of Excessive Closing Time of the Check Valve for Steam Turbine

This paper introduces the structure and working principle of the check valve for steam turbine, and the composition of the closing time of the check valve. Some power plants are selected as the object of analysis, the data of closing time of corresponding valves are counted, and the reason of exceeding time of the valves is analyzed. The reasons for the excessive shutdown time include the control loop delay time and the mechanical delay time. So the optimization suggestions are put forward, including adding ETS and OPC hardwiring circuits, shortening the execution cycle of logic pages in the controller appropriately under the conditions of controller performance, strengthening the quality control of valve installation and maintenance, reforming or adjusting the cylinder spring, increasing the spring rebound which can shorten the delay time and closing time effectively, and have reference significance to treat the problem of the excessive closing time of the check valve for the steam turbine.