2
FIGURE 4 - TYPICAL PIPING SCHEMATIC
FIGURE 3 - E-12
™
DUAL BRAKE VALVE CROSS
SECTIONAL VIEW
26
30
31
32
10
14
25
24
15
LOWER BODY
18
19
UPPER BODY
5
7
6
8
9
15
13
10
17
12
13
14
11
1
2
3
4
4
21
23
22
20
28
27
29
The circuits in the E-12
™
/E-15
™
valves are identified as
follows: The no. 1 or primary circuit is that portion of the
valve between the primary piston (2) and the secondary
piston (18); the no. 2 or secondary circuit portion consists
of the area between the secondary piston and the exhaust
cavity.
The supply, delivery and exhaust ports of the E-12
™
/E-15
™
brake valves are identified by designations cast into the valve
body adjacent to their associated port. (See Figure 1). The
primary supply and delivery ports are located in the upper
body portion while the secondary supply and delivery ports
are located in the lower body portion of the valve.
The primary circuit of the valve is similar in operation to a
standard single-circuit air brake valve and under normal
operating conditions the secondary circuit is similar in
operation to a relay valve.
Both the primary and secondary circuits of the brake valve
use a common exhaust protected by an exhaust diaphragm.
OPERATION
APPLYING: NORMAL OPERATION-PRIMARY
CIRCUIT PORTION
When the brake treadle (26) is depressed, the plunger (27)
exerts a force on the spring retainer (7), graduation spring
(8) and primary piston (2). The primary piston, which con-
tains the exhaust valve seat closes the primary circuit
exhaust valve. As the exhaust valve closes the inlet valve for
the primary circuit moves off of its seat allowing the air from
the supply port of the primary circuit to flow out the delivery
port of the same circuit.
QUICK
RELEASE
VALVE
TP-5
™
TRACTOR
PROTECTION
MV-3
™
MODULE
BRAKE
CHAMBER
SLACK
ADJUSTER
COMPRESSOR
SUPPLY
RESERVOIR
#1 SERVICE
RESERVOIR
#2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
SPRING
BRAKES
SLACK
ADJUSTER
DUAL BRAKE
VALVE
TRAILER
CONTROL
VALVE
BP-R1
™
BOBTAIL
PROPORTIONING
VALVE
AIR DRYER
12
11
