Abstract: A demand valve for a respirator. A fixed tube directs pressurized air flow from the source into an opening for a mask. The venturi effect caused by directed air flow through the housing acts to draw the diaphragm toward the respirator face mask. A portion of the air directed by the tube escapes and is directed over the tube by a hinged three sided arm. Air flow so directed by the arm creates a low pressure area within the arm thus pulling the arm toward the tube. The arm is in engagement with the stem of an air valve which when the arm is drawn toward the tube opens the valve to provide continued air flow into the mask without continued effort on the user's behalf.