| 摘要 |
PURPOSE:To reduce the cost of equipment by providing two discs, driven separately, on the same axis and enabling each disc to be seated on individual valve seat formed around an outflow port so as to furnish one valve body with functions of an adjustment valve and an emergency shut-off valve. CONSTITUTION:In case of using this valve device, equipped in a steam extraction line branching off from an airline between a boiler and a turbine in a steam power plant, as an adjustment valve, the second disc 22 united in one body with a piston 24 is placed in an illustrated position to secure a passage for an entrace side fluid 20 by means of a gap 31. In this condition, the flow of steam is controlled by vertically moving the first disc 18 by means of an actuator 16 through a stem 12. On the other hand, in case of using this valve as an emergency shut- off valve, a pilot valve 33 is opened and the entrance side fluid 20 is introduced into an upper chamber 25 to press down the piston 24. Then the second disc 22 is pressed to be seated on a valve seat 23, and communication between inflow and exit ports 7, 8 is shut-off regardless of a position of the disc 18. |
