| 摘要 |
PURPOSE:To reduce the action of thermal shock on a valve casing by using a system in which an annular steam chamber is provided on the periphery of the downstream region of the valve seat of the casing, the steam chamber is connected with the upstream region of the valve seat by a pipe, and a supply valve through which steam is supplied by an external signal to the pipe. CONSTITUTION:In a casing 11, annular steam chambers 20-22 are formed from a valve seat 13 to a valve outlet, and these steam chambers 20-22 are connected with a steam chamber a and a condenser through pipelines 23-25. Also, supply valves 26 and 27 are provided to the pipelines 23 and 24 and control on the opening and closing of these valves 26 and 27 is made by a command signal. Thus, since the distribution of temperatures in each portion of the casing becomes equalized, thermal shock action is reduced. |
