The opening directions of the two non-return valves produce a displacing direction of the high pressure pump according to the invention from the feed to the outlet or from the first non-return valve to the second non-return valve.

The non-return valve (40) comprises a ducks beak check valve.

The invention relates to a piloted, blockable non-return valve and a hydraulic drive of a moulding unit, in which a non-return valve of this type is used.

The first check valve adapted to receive an input from the second check valve.

The second check valve and the third check valve are in opposite directions.

The check valve is adapted to sealingly engage the check valve seat.

The second check valve and the first check valve are connected and are in the same direction.

The check valve composed of a check ball supported by a check valve spring installed in a check valve cover is installed on a check valve sheet installed at the lower end of the piston.