Abstract: The present invention relates to a water supply pipe for a steam generator.The supply pipe comprises the following elements in a substantially horizontal portion (3) thereof:A lower baffle plate (4) defining or limiting an upper opening (7),And an upper baffle plate (5) defining or limiting a lower opening (9) and being disposed upstream of the lower baffle plate with respect to the normal flow direction of the water.The horizontal edge (8) defining the upper opening is disposed higher than the horizontal edge (10) defining the lower opening.As a result, the two baffle plates form between them a hydraulic barrier, which, when the water supply is cut off or reduced, prevents or substantially limits the passage of steam coming from the generator.