| 摘要 |
A valve unit for controlling the delivery of a fuel gas through a delivery duct (3) comprises a valve seat (6) in the duct, a closure member (5) associated with the seat, a motor-driven actuator (7) acting on the closure member in order to control it so as to open/close the valve seat, as well as an electromagnetic unit (22) with a first portion (23) carrying a magnetizin g winding (24) and a second portion (25) which can be fixed firmly to the firs t portion by magnetization. The electromagnetic unit (22) is associated with t he actuator in order to act on the closure member (5) so as to close the valve seat (6), irrespective of the operative position of the actuator (7), upon t he occurrence of a predetermined condition which requires the valve seat to be shut off, and the actuator means (7) is movable, together with the second portion (25) of the electromagnetic unit, during the movement to control the closure member (5) so as to open/close the valve seat, the first portion (23 ) of the electromagnetic unit being connected to a stationary structure of the valve unit.
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