| 摘要 |
PURPOSE:To reduce the capacity of a valve drive mechanism and improve centering of a valve by forming a steam control valve comprising a main valve equipped with a guide which fits a stand and a sub-valve slidingly installed in the main valve. CONSTITUTION:A steam control valve which is arranged between the lower side chest 3 of a turbine casing and a nozzle box 5, is composed of a main valve 11 equipped with a guide 12 which fits the external surface of a stand 10 with nicro-clearance and sub-valve 15 movably installed in the sub-valve chamber 11a of the main valve. The sub-valve 15 is driven by a valve spindle 17, fitting on a sub-valve seat 11d. Consequently, it is possible to reduce the capacity of the valve control mechanism and improve the contering of the valve. |
