This 1 1/4-2 IN bonnet repair kit for the pressure vacuum breaker, series 800, prevents the reverse flow of polluted water from entering into the potable water supply due to backsiphonage. It consists of a float vent, disc assembly and bonnet O-ring. It is ideal in health hazard continuous pressure applications such as irrigation systems and industrial process water systems where the water enters the equipment at or below its flood rim.