HomeLandscape & TurfProductsDripline Components Dripline Components Low Volume Control Zone Kits Valve, filter and pressure regulator completely assembled for easy, cost effective installation. Pressure Regulators Providing constant outlet pressure. Air Vents Used to control air in irrigation systems for proper watering and accurate flow measurement. Automatic Flush Valves Helps reduce maintenance to your irrigation system and increase dripline performance. In-line Check Valve Prevents backflow of water and drainage of the system into low areas. Operation/Pressure Indicator Stakes Operation flag raises to indicate drip system operation and Fogger indicates operation at required system pressure.