Bendix Commercial Vehicle Systems AD-IP INTEGRAL PURGE AIR DRYER 5/07 - Manual (Page 4)

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FIGURE 5 - AD-IP ™ INTEGRAL PURGE AIR DRYER PURGE CYCLE
The actual reactivation of the desiccant drying bed begins
as dry air flows from the purge volume through the purge
orifice in the desiccant cartridge bolt, then through the center
of the bolt and into the desiccant bed. Pressurized air from
the purge volume expands after passing through the purge
orifice; its pressure is lowered and its volume increased.
The flow of dry air through the drying bed reactivates the
desiccant material by removing the water vapor adhering to
it. Generally 30 seconds are required for the entire purge
volume of a standard AD-IP
™ air dryer to flow through the
desiccant drying bed.
The delivery check valve assembly prevents air pressure in
the brake system from returning to the air dryer during the
purge cycle. After the 30 second purge cycle is complete
the desiccant has been reactivated or dried. The air dryer is
ready for the next charge cycle to begin. However the purge
valve will remain open and will not close until air brake
system pressure is reduced and the governor signals the
compressor to charge the system.
TURBO CUTOFF FEATURE (Refer to Figure 6)
The primary function of the turbo cutoff valve is to prevent
loss of engine turbocharger air pressure through the AD-IP
™
air dryer in systems where the compressor intake is
FIGURE 6 - AD-IP ™ INTEGRAL PURGE AIR DRYER TURBO
CUTOFF
DESICCANT
BED
PURGE
VOLUME
DISCHARGE
PORT EXHAUST
PURGE
VALVE TURBO
CUTOFF
VALVE
ENGINE
TURBO
COMPRESSOR
GOVERNOR
PURGE
CONTROL
LINE
CONTROL
PORT
SUPPLY
PORT
OIL
SEPARATOR
PURGE
ORIFICE
SUPPLY
PORT
TURBO
CUTOFF
VALVE
CONTROL
PORT
PURGE
VOLUME
PURGE
VALVE
DELIVERY
CHECK VALVE
(OLD STYLE
SHOWN)