Abstract:
A safety air gap system for an exemplary high volume evacuator having a water-sealed pump to provide suction thereto and including a gray water discharge from the pump to a drain, the system including a closed housing adapted to be mounted at a higher level than the evacuator, a reservoir for fresh water in the housing terminating a predetermined distance below the top, a coaxial pair of inner and outer tubes extending upward from the bottom of the reservoir and terminating above the top of the reservoir, the lower end of the inner tube receiving municipal water for discharge at the top to the outer tube which discharges the water at the lower end to the reservoir as controlled by a float-operated valve between the upper ends of the tubes, the housing having in one sidewall an outlet port connectable to a drain at a level below the top of the reservoir to prevent accidental filling of the housing with water in the event of a malfunction of the system, and an air gap opening positioned in a sidewall of the housing at a level above the outlet opening but no higher than the top of the reservoir to permit any water overflowing from the reservoir to discharge therethrough without creating suction in the event of a stoppage of the outlet opening to a drain.