Valve Operation - BENDIX AD-SP SYSTEM PURGE AIR DRYER Manual

SUPPLY
PORT
GOVERNOR
COMPRESSOR
FIGURE 3 - AD-SP ™ AIR DRYER CHARGE CYCLE
The air dryer will remain in the charge cycle until the air
brake system pressure builds to the governor cutout setting.
To protect against over pressurization of the AD-SP
dryer, the purge valve incorporates an integral relief valve
feature. In the event that the compressor unloader
SUPPLY
PORT
MALFUNCTIONING
GOVERNOR
COMPRESSOR
FIGURE 4 - AD-SP ™ AIR DRYER RELIEF VALVE OPERATION
OIL
SEPARATOR
CONTROL
PORT
TURBO
CUTOFF
PURGE
PISTON
ENGINE
TURBO
OIL
SEPARATOR
CONTROL
PORT
TURBO
CUTOFF
PURGE
PISTON
ENGINE
TURBO
PURGE
ORIFICE
PURGE /
EXHAUST
RELIEF
PORT
VALVE
mechanism or governor malfunctions, at approximately 200
psi supply air pressure the AD-SP
™ will open (without control pressure), and vent excess air
air
pressure to atmosphere (refer to Figure 4).
PURGE
ORIFICE
PURGE /
EXHAUST
RELIEF
PORT
VALVE
DESICCANT
DELIVERY
CHECK
RESERVOIR
DELIVERY
PORT
™
SC-PR
VALVE
™ air dryer purge valve
DESICCANT
DELIVERY
CHECK
RESERVOIR
DELIVERY
PORT
SC-PR ™
VALVE
REAR
FRONT
RESERVOIR
REAR
FRONT
RESERVOIR
3