High temperature steam valve and steam turbine plant

Abstract

A high temperature steam valve has a valve casing including a main steam inlet, a main steam outlet and a valve chest. The high temperature steam valve also has a valve seat positioned in the valve chest, a valve element facing the valve seat, and a valve rod slidably penetrating the valve casing to drive the valve element. A cooling steam hole is provided to surround a valve-rod penetrating portion of the valve casing. Cooling steam can be poured into the cooling steam hole from outside through a cooling steam inlet hole and steam having finished heat exchange can be exhausted from a cooling steam outlet hole into the valve chest. The sliding portion between the valve rod provided in the valve-rod penetrating portion of the valve casing and bush is cooled to prevent oxidized scale from depositing on the sliding portion.

Dependencies are inferred from the claim text.