Abstract: A blanking cover for a pipe comprises a plate able to close the pipe by tilting or rocking under the action of gravity, about a pivot pin to which it is fixed. A part is fixed to the pin, and an electromagnet able to retract the part and fixed to another part rotates on the pin and a jack is provided for actuating the other part. When excited, by attracting the part, the electromagnet makes it possible to keep the pipe open. Its deexcitation leads to the tilting of the plate and consequently to the closing of the pipe. If a tilting or rocking problem occurs, the action of the jack on the other part brings about the tilting by displacing the part. In order to reopen the pipe, the jack is actuated so as to press the excited electromagnet against the part and is then actuated in the opposite direction.