PERFECCIONAMIENTOS EN SERVOVALVULAS DE MODO DUAL

摘要

A dual mode valve actuator for automatically controlling the operation of a valve comprises a first reversible drive motor and a first planetary drive assembly which operate to move the valve stem axially during a first mode of operation. The actuator further comprises a second drive motor and a second planetary drive assembly which cooperate with the first planetary drive assembly to rotate the valve stem without axial movement during a second mode of operation. A control means is provided to control the operational mode of the actuator.