Abstract: A foam generating nozzle is disclosed comprising a cylindrical housing, a first inlet at one end of the housing for connection to a supply of foamable liquid under pressure, a second inlet at the first end for air supply, a foam discharge outlet at the other end of the housing, a diffuser associated with the first inlet and a conical screen of a non-corrosive material disposed in said housing between the ends with its apex directed toward the discharge outlet, to provide a screen surface area larger than the inlet air supply area, such that in operation the foamable liquid is sprayed onto the screen by the diffuser in a pattern which matches the conical shape of the screen, while air is dragged through the screen thereby generating the foam.