ASSE (Plumbing) 1098-2021

ASSE 1098 provides performance criteria for atmospheric vacuum breakers (AVB) installed on vacuum toilet assemblies and galley waste disposal units (GWDU) designed to be installed on passenger aircraft.

Atmospheric type vacuum breakers shall be integral. The purpose of these devices is to provide protection of the potable water supply against pollutants or contaminants that enter the system due to backsiphonage through the outlet. Under backsiphonage conditions, a small amount of water is permitted to exit through the air-ports. The AVB shall:

• a) Have its outlet open to pressure in the cabin;
• b) Not be subjected to backpressure;
• c) Not be subjected to more than twelve (12) hours of continuous water pressure;
• d) Be deck mounted/equipment mounted; and
• e) Be installed with its critical level (CL) not less than 1.0 inch (25.4 mm) above the overflow level of the fixture served.