The PURGEnVENT Model 7950ILV In-Line Automatic Air Venting Valve features a separation chamber engineered to remove air as the fire protection system is filled with water to help prevent pipe corrosion.The separation chamber and air scoop is designed to force a separation of air from the water as the system fills. Since the chamber has a larger diameter than the branch line, water entering the chamber is momentarily slowed allowing the heavier water to drop as the air rises and is scooped into the venting assembly. As water exits the chamber it is reduced back to the branch line's pipe diameter which pushes air back towards the back side of the air scoop through it's Quick Vent Channel where it is released by the M7900AAV. The larger diameter of the M7950ILV separation chamber allows air remaining in the system to be more effectively released by the 7900AAV. When draining the system unscrew the cap and open the purge valve, this will act as a vacuum break helping to drain the system more effectively while reducing the need to reseat gaskets while refilling the system.