Abstract: An applicator for applying chemical treating fluid to equipment, such as pump-sucker rod equipment, being run into a well includes a housing capable of being mounted on a wellhead and having an opening to permit passage of the equipment therethrough. A series of circumferentially spaced apart nozzles are arranged in the housing for directing flow of the chemical radially onto said equipment. Valve means are provided for controlling the flow of the chemical to the nozzles. A movable actuator which operates the valve means has a first position at which flow of the chemical through the valve is prevented and a second position at which flow of the chemical through the valve is permitted. The actuator includes spring means for urging the actuator to the first position thereof and means supported on the housing, which is responsive to the weight of the suspended equipment in the well to move the actuator to the second position thereof.