A siphon guard includes a housing having an inlet and an outlet. A primaryflow path is disposed within the housing and is in fluid communication withthe inletand the outlet. A secondary flow path is disposed within the housing and is influidcommunication with the inlet and the outlet. The secondary flow path has ahigherresistance to fluid flow than the primary path. A valve is disposed within theprimary flow path. The valve has a valve seat and a first ball and a secondball. Thefirst ball is movable by gravity between a valve closed position, where thefirst ballis in contact with the valve seat, and a valve open position, where the firstball isspaced from the valve seat. The first ball is disposed between the second ballandthe valve seat. The second ball is movable by gravity between a valve closedposition and a valve opened position.
