Steam valve and steam turbine plant

摘要

A steam valve (2) has: a valve casing (5); a valve seat (8); a main valve body (14) slidable to abut to or to detach from the valve seat; a bypass valve body (15) slidably disposed in the main valve body; a cylindrical flow guide (21) surrounding the annular wall (16) of the bypass valve body; and a strainer (9) surrounding the main valve body and the flow guide. The bypass valve body has a steam passage (18) and the annular wall that protrudes out of the main valve body when the bypass valve body is in an open position. The annular wall has steam inlet ports (17). The flow guide guides steam from outside to flow through a space between the annular wall and the flow guide so as to admit steam into the steam passage in the bypass valve body through whole peripheral part of the annular wall.