| 摘要 |
The invention relates to a device comprising at least one safety shut-off control valve. A safety valve is optionally connected to said safety shut-off control valve, connected in series in the fluid flow path. In the safety shut-off control valve, a sealing valve is returned to a sealing position against a seat by means of a return spring, and is controlled by a linear actuator and a connecting rod for continuous adjustment of the valve opening. The connecting rod comprises two independent segments which are at least partially made from a ferromagnetic material and which are magnetically coupled to a magnetic coupling circuit that is activated by a coil. While electric power is being supplied to the coil, the magnetic field that said coil creates maintains the linking rod segments coupled to one another, such that the linear actuator can control the sealing valve. Once the power being supplied to the operating coil is interrupted, the segments separate and the sealing valve returns to said sealing position regardless of the position of the linear actuator. At the same time, the check valve of the safety valve is pushed back to the sealing position by a return spring. In this way, a continuous control valve with a double safety system is produced.
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