BC Transit – Air Brake Course

Automatic Drain Valve (“Spitter(
Spitter” Valve)
Safety Valve
Low air warning device
Wet tank
Dry Tank
Automatic
Drain Valve
Drain Valve
Drain Valve
The Automatic Drain Valves (“Spitter” Valve) are optional devices which aid in reducing the
amount of moisture and contaminants that collect in the air brake system. These valves are
installed on some or all of the reservoirs, or connected to the compressor/governor, or the foot
valve on some air brake systems.
Most are self-contained and momentarily open each time reservoir pressure falls (typically
following a brake application) or each time the compressor cycles.
Some Automatic Drain Valves are equipped with an electric heating element to prevent
freezing in cold weather.
110