Abstract: A portable, self-contained powered sprayer to produce a foam effluent spray from a liquid. The sprayer includes segregated air and liquid delivery systems that separately supply air and liquid to a mixing chamber. The liquid delivery system may include a pump for pumping liquid from a tank to the mixing chamber via a liquid supply line. The air delivery system may include a compressor for supplying pressurized air to the mixing chamber via an air supply line. The mixing chamber may be defined within a flow controller. In one embodiment, the sprayer includes control circuit for engaging and disengaging the pump and the compressor in response to operation of the flow controller. The control circuit may include a pressure switch operatively connected to the liquid supply line to trigger operation of the pump and the compressor in response to pressure within the liquid supply line.