BENDIX R-12DC Service Data - Page 3
Browse online or download pdf Service Data for Control Unit BENDIX R-12DC. BENDIX R-12DC 8 pages. Relay valve with biased double-check
Also for BENDIX R-12DC: Manual (8 pages), Installation Instructions (4 pages)
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BRAKE
CHAMBER
QUICK
RELEASE
VALVE
MODULATOR
Figure 3 – Typical System Schematic
OPERATION
APPLICATION
Under normal conditions, the internal biased double-check
valve ensures that the primary service signal controls
the valve. Air pressure delivered to the primary service
port enters the small cavity above the piston and moves
the piston down. The exhaust seat moves down with
the piston and seats on the inner or exhaust portion of
the inlet/exhaust valve, sealing off the exhaust passage.
At the same time, the outer or inlet portion of the inlet/
exhaust valve moves off its seat, permitting supply air to
flow from the reservoir, past the open inlet valve and into
the service brake chambers. In the event of a loss of the
primary service line, (see Figure 5) the double-check valve
mechanism in the cover of the Bendix
move, shutting off the primary service line, and instead
allow the secondary service line to apply the air pressure
needed to operate the valve.
Note: Secondary service line may leak out of the primary
service at control pressures up to 20 psi when the primary
signal is not present.
PARK
CONTROL
VALVE
BRAKE
VALVE
DOUBLE
CHECK VALVE
#2 SERVICE
RESERVOIR
SUPPLY
R-12DC
valve will
®
®
SLACK
ADJUSTER
BENDIX
®
SR-1
™
VALVE
BENDIX
®
R-12DC
®
VALVE
#1 SERVICE
RESERVOIR
BENDIX
R-12DC
®
®
VALVE
RELAY PISTON
INLET
EXHAUST
VALVE
RESERVOIR
ANTILOCK SENSOR
TONE RING
Figure 4 – Bendix
R-12DC
®
Typical System Components
SPRING
BRAKE
BENDIX
®
R-14
®
RELAY
VALVE
BRAKE VALVE
(DELIVERY
LINES ARE
SHOWN)
ANTILOCK
MODULATOR
EXHAUST
PORT
BRAKE
CHAMBERS
Valve Sectional View with
®
3