BENDIX PP-7 User Manual
®
Bendix® PP-7™ Trailer Supply Valve
NUT & THREAD
1/8 P.T.
SUPPLY
EXHAUST
SD-03-3617
FUNCTION AND DESCRIPTION
The PP-7™ trailer supply valve provides in cab control for the
tractor protection system and functions in conjunction with
the park control valve. It is responsible for synchronizing the
tractor and trailer parking and emergency brakes.
It is essentially a combination of two non-modulating, onoff control valves in a single, compact package.
Each of the four pipe tapped ports of the PP-7™ valve are
identified with cast in, raised letters. The supply and control
ports have 1/8 inch N.P.T.F . dry seal pipe threads while the
delivery and exhaust ports have 1/4 inch N.P.T .F. dry seal
pipe threads.
LOCK
WASHER
CAP SCREW
FIGURE 1 - EXTERIOR
(17) PLUNGER
(18) PLUNGER
RETURN
SPRING
HEX LOCK NUT (15)
(12) O-RING
(13) INLET &
EXHAUST
VALVE
1/4 P.T. DELIVERY
(9) O-RING
1/8 P.T. CONTROL
LOCK
WASHER
CAP SCREW
GENERAL OPERA TION
The PP-7 trailer supply valve is a panel mounted, push-pull
operated control valve. The button of the PP-7™ valve must
be manually depressed, but will automatically pop out and
exhaust if supply air is below 40 p.s.i. Fifty p.s.i. or greater
supply air pressure is required for the button to remain in
BUTTON (2)
SPIROL
PIN (1)
THIN NUT
O-RING (19)
BODY
INLET & EXHAUST
(16) VALVE
RETAINING RING (10)
SEALING RING (3)
O-RING RETAINER (11)
INLET & EXHAUST (14)
VALVE SPRING
SPRING (7)
LOWER BODY
PISTON (6)
O-RING (8)
O-RING (5)
FIGURE 2 - SECTIONAL
END PLATE (4)
1
PP-7
Control
Valve
™
TRACTOR DUAL AIR BRAKE SYSTEM
™
TP-3
Tractor Protection
DS-1
Park
Control
LQ-3
Modulator
FIGURE 3 - PIPING DIAGRAM
™
Valve
Double Check
Supply
Reservoir
™
E-7
Dual
Brake Valve
Valve
#1 Service
Reservoir
SR-1™ Spring
Brake Valve
LP-3™ Low
Pressure Indicator
#2 Service
Reservoir
SB-3
R-8
™
SB-3
RELAY
VALVE
SB-3 SB-3
PP-7™ VALVE LESS THAN 50 PSI
SYSTEM PRESSURE
To
Parking
Brakes
Double
Check
Valve
FIGURE 4 - PP-7
™
TRAILER SUPPL Y V ALVE LESS THAN 50 PSI SYSTEM PRESSURE
Park
Control
Valve
#1 Service
Reservoir
#2 Service
Reservoir
Inlet & Exhaust
Exhaust Vent
To Tractor
Protection
Control Port
Supply
Port
Plunger
Control Inlet
and Exhaust
Exhaust
Port
Control
Piston
2
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