Bendix Commercial Vehicle Systems PP-3 TRAILER SUPPLY VALVE 3/04 - Manual

1
®
Bendix ® PP-3 ™ Trailer Supply Valve
SD-03-3613
FIGURE 2
MOUNTING
NUT
PP-3 ™
CONTROL
VALVE
DELIVERY
PORT
NO. 2
RESERVOIR
TC-2 ™ VALVE
FIGURE 1 - PP-3 ™ TRAILER SUPPLY VALVE EXTERIOR
SUPPLY
PORT
BUTTON
TP-3 ™
TRACTOR
PROTECTION
VALVE
DOUBLE
CHECK
VALVE
COMPRESSOR
TRAILER SERVICE
LINE
TRAILER
EMERGENCY LINE
BRAKE
VALVE
NO. 1
RESERVOIR
DESCRIPTION
The PP-3 ™ trailer supply valve, installed in the cab, operates
in conjunction with a TP-3 ™ tractor protection valve to supply
air under pressure to the trailer and protect the tractor air
supply in case of a break-away or an air leak on the trailer
which would reduce the pressure in the trailer supply line
below the design trip point of the PP-3
™ valve.
With reference to Figure 2 the supply port of the PP-3 ™
valve is supplied from the towing vehicle reservoir. Its
delivery goes directly to the supply port on the TP-3
™ tractor
protection valve.
OPERATION
The PP-3 ™ control valve is a push-pull operated valve. The
button must be pushed in to open the valve. The button will
not stay in unless there is 50 psi or more in the supply line.
Once the pressure is enough that the button will remain in,
air flows through the tractor protection valve to the trailer.