Abstract: An improved water sprinkler of the impact-arm type is provided in which nozzle reaction forces, impact arm acceleration forces and gravitational forces are completely balanced by the use of at least two diametrically opposed nozzles, and two diametrically opposed impact arms mounted for movement as a single unit.

Abstract: A self-cleaning filter assembly for use in a solenoid-actuated valve of the type having fluid pressure-operated diaphragm to control opening and closing of the valve, the diaphragm operating in response to fluid pressure admitted from the inlet chamber of the valve into a control chamber to maintain the valve in a closed position, and when the fluid pressure in the control chamber is relieved by actuation of the solenoid, to open the valve. The self-cleaning filter assembly filters control fluid admitted to the control chamber, and comprises a filter element cleaned by a brush each time the valve is opened or closed, thereby to prevent clogging of the filter during use.