| 摘要 |
Existing steam chests having a plurality of valves which are incapable of operation by individual high pressure valve actuators may be modified to provide apparatus for transferring operation of a steam turbine at less than a full load betweeen a full-arc admission mode and a partial-arc admission mode. For those steam chests of the internal bar lift type, the outboard valves are disconnected from the bar and coupled directly to respective servomotors. As such, the pre-existing servomotor utilized to lift the internal bar, as well as the additional servomotors for the outboard valves, are operatively connected to a conventional control means. In those steam chests of the external bar lift type, an additional servomotor is coupled through an actuator rod to the pre-existing pivot point of the external bar, and is thereafter controlled by conventional means for interactively activating the pre-existing servomotor and the additional servomotor.
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