Device for closing an opening of a tank or a tubular conduit

A device for closing an opening of one of a tank and a tubular conduit, the device comprising:

• a plate for closing the opening and movable substantially perpendicular to a plane of the opening toward the opening to be pressed against a wall in which the opening is formed, and away from the opening;
• the closing plate being displaceable, in a position thereof in which it is spaced from the opening, substantially parallel to the plane of the opening;
• a first piston-cylinder unit for displacing the closing plate parallel to the plane of the opening and having a housing with a cylinder bore and at least one piston displaceable in the cylinder bore relative to the housing;
• a second piston-cylinder unit for moving the closing plate toward and away from the opening perpendicular to the plane of the opening and having a cylinder bore and at least one piston displaceable therein and connected with the closing plate for moving the closing plate against the wall in which the opening is formed and away from the wall;
• and
• conduit means for communicating pressure medium to the cylinder bores of the first and second piston-cylinder units for displacing respective pistons in the respective cylinder bores.