Steam valve apparatus

摘要

In one embodiment, a steam valve apparatus includes: a steam valve (200) passing or blocking a steam to a turbo machine; a piston (202) operated by a hydraulic liquid to open or close the steam valve; a hydraulic cylinder including an internal space sectioned into a first chamber (204) and a second chamber (205) by the piston, the first chamber being on a close side of the steam valve, and the second chamber being on an open side of the steam valve; a first passage (pl9) to supply the hydraulic liquid to the first chamber (204); a second passage (pl7) connecting the first chamber and the second chamber; a third passage (pl8) to drain the hydraulic liquid from the second chamber; an electromagnetic valve (521,522) switched between a first state and a second state based on an input of a signal; a first cartridge valve (29,30) opening the first passage when the electromagnetic valve is in the first state and closing the first passage when the electromagnetic valve is in the second state; and a second cartridge valve (525,526) closing the first passage when the electromagnetic valve is in the first state and opening the first passage when the electromagnetic valve is in the second state.