The present invention relates to a system for spraying a washing liquid, comprising a washing liquid tank, a plurality of spray members fluidically connected to the tank, a pump configured to supply the spray members with washing liquid, a plurality of valves coupled respectively to the plurality of spray members and configured to selectively transmit the pumped washing liquid to the respective spray members, wherein the plurality of valves are disposed in the form of a distribution block with an inlet of the block being configured to be fluidically connected to the pump and comprising fluidic connectors disposed in parallel and intended to be connected to spray members, and wherein the distribution block also comprises a mechanical overpressure valve disposed in parallel with the fluidic connectors and configured to be fitted on a fluidic connector of the distribution block.