The purpose of the vacuum breaker / anti-siphon system (also called a drain back dam) is to retain water in the header system during shut down and to eliminate air purge and shock to plumbing during start up.
It is necessary to duplicate this arrangement on both the supply and return lines.
The drain-down valve allows header draining for system maintenance and is closed during normal operation.
The vacuum breaker must be located a the highest point in the system nearest to the tank to be most effective. A nipple length of 8 inches minimum is required to create sufficient vacuum to open the Cash Acme breaker valve.
This drawing is supplied to demonstrate a possible piping configuration for the equipment and is general in nature showing pipe sizes and basic routing>
It is not intended to be inclusive of every detail required for specific location and installation.
Consult with a professional engineer to determine specific needs before installation.