Air Valves Potable Water - Double Air Valve + BFV Isolation

- Air valves should be installed with isolation valves to permit allow repairs or inspections to be completed without stopping the system.
- Wafer lugged Butterfly valves are ideal for this duty as they are retained on the mount flange by the studs fitted through the tapped lugs.
- The butterfly valve should always be fully open when the air valve is in use
- Butterfly valve shown is in the closed position.
Section 4.8