Steam turbine control valve

摘要

A control valve for use in the steam chest of a steam turbine is provided. Considerable stiffness is imparted to the valve by employing a large diameter spring housing which encloses the valve springs. In addition, the bonnet of the valve is oversized and the screws attaching the bonnet to the steam chest are arranged in a circle inside the spring housing, thereby allowing the spring housing to be attached to the bonnet by a plurality of screws arranged in a large circle around the outside of the spring housing. The spring housing lower flange engages a spigot on the bonnet in a tight fit. The spring seat slides within the spring housing and has integral lugs which extend through windows in the spring housing. The lugs allow the spring seat to be restrained to the upper flange of the spring housing so that the coupling connecting the valve actuator piston rod to the valve steam can be assembled and disassembled during installation and maintenance.