Bendix Commercial Vehicle Systems AD-9si Oil Coalescing Air Dryer - Manual (Page 7)

7
COMPRESSOR
DESICCANT
BED
DELIVERY
CHECK
VALVE
PURGE
VALVE
TURBO
CUT-OFF
VALVE
(CLOSED)
CONTROL
PORT
SUPPLY
PORT
FRONT
RESERVOIR
SAFETY
VALVE
REAR
RESERVOIR
PURGE
ORIFICE
OIL
COALESCING
FILTER
CONTROL
LINE
PURGE AIR
EXTENDED
PURGE
PORT
EXHAUST
DELIVERY
PORT
FIGURE 5 - BENDIX ® AD-9si ™ AIR DRYER WITHOUT GOVERNOR—PURGE CYCLE
TURBO CUT-OFF FEATURE (Refer to Figures 3
and 5)
The primary function of the turbo cut-off valve is to prevent
loss of engine turbocharger air pressure through the
Bendix ® AD-9si ™ air dryer when the dryer is in the purge
mode.
At the onset of the purge cycle, the downward travel of the
purge piston is stopped when the turbo cut-off valve (the
tapered portion of the purge piston) contacts its mating
metal seat in the purge valve housing. With the turbo cut-off
valve seated (in the closed position), air in the compressor
discharge line — as well as the AD-9si air dryer inlet port
— cannot enter the air dryer. By completing these actions,
the turbo cut-off effectively maintains turbocharger boost
pressure to the engine.