Abstract: A chemical spray system includes a nozzle assembly and a suction pipe in flow communication with the nozzle assembly. A waste liquid tank is in flow communication with the suction pipe. A first valve assembly is located in a flow path of the suction pipe between the nozzle and the waste liquid tank. A generator, located in the flow path of the suction pipe between the first valve assembly and the waste liquid tank, induces fluid flow from the first valve assembly to the waste liquid tank. The nozzle assembly is suctioned via the suction pipe when the first valve assembly is in an open position. A cleansing fluid supply assembly is in flow communication with the suction pipe between the first valve assembly and the generator. Thus, a chemical can be cleaned from the generator with cleansing fluid to prevent corrosion and failure of the generator in advance.