Continuous Automatic Combination Air Vent by Irritec
Continuous Automatic Air Vent/Vacuum Relief Valves allow air that remains in the system, or enters the system after startup, to escape. These will automatically expel any air which collects in the system once the system is filled up to pressure and flowing. At shut down they will allow air to enter the lines reducing the possibility of dirt and debris entering through the emitters due to back siphoning or back pressure, thus reducing clogging. Continuous Air Vent/Vacuum Relief Valves are commonly used at high points or upstream of manifolds, sometimes along mains or at the end of mains, and recommended every 1,000 feet along mainlines 6 inches and larger. Proper air vent/vacuum relief is essential in sub-surface systems.