Subsea shut-off device

1. A subsea shutoff device, in particular for use in water depths of more than 30 m for operating a valve with a gate, said subsea shutoff device comprising:

a housing, which is waterproof and oil filled;

a crank mechanism arranged in the housing; and

a rotary actuator,

wherein the rotary actuator is adapted to operate the gate of the valve via the crank mechanism,

wherein the crank mechanism comprises a thrust crank mechanism with a crank, a thrust rod and a joint rod with a first and a second end, wherein the first end of the joint rod is fixed on the crank, and the second end of the joint rod is connected with the thrust rod via a joint, and the thrust rod is adapted to operate the gate of the valve,

wherein the crank comprises a first end stop and a second end stop, and a rotational movement of the crank is only possible between the first and the second end stop,

wherein the first end stop and the second end stop define a maximum angle of rotation for the crank of more than 180°,

wherein the first end stop and the second end stop define a maximum angle of rotation for the crank, and the maximum angle of rotation is less than 240° max, and

wherein the rotary actuator comprises an electric motor and a transmission.

2. The subsea shutoff device according to claim 1 , wherein the valve and the gate are connected with the rotary actuator with the thrust rod.

3. The subsea shutoff device according to claim 1 , wherein the gate shuts off the valve when the joint rod is at the first end stop, and wherein the gate opens the valve when the joint rod is at the second end stop.

4. The subsea shutoff device according to claim 1 , wherein the crank mechanism comprises a first dead center and/or a second dead center, and the first end stop is arranged close to the first dead center and/or the second end stop is arranged close to the second dead center.

5. The subsea shutoff device according to claim 1 , wherein the crank mechanism comprises a linear guiding restricting the thrust rod to a substantially one-dimensional movement.

6. The subsea shutoff device according to claim 1 , wherein the subsea device is configured to withstand at least a depth pressure in 1000 m water depth.

7. The subsea shutoff device according to claim 1 , wherein the subsea shutoff device is used for controlling a fluid in an oil or gas extraction plant in a water depth of at least 30 m.