BENDIX SR-1 SPRING BRAKE VALVE - Service Application Scenarios; Normal Service Application; Service Application with Loss of No. 2 Reservoir Pressure

3
FIGURE 6 - NORMAL SERVICE APPLICATION
FIGURE 5 - SYSTEM FULLY CHARGED
#1 SERVICE
RESERVOIR
#2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
PARK
CONTROL
SB-3
PISTON B
CHECK VALVE
INLET &
EXHAUST A
PISTON A
INLET &
EXHAUST
B
EXHAUST
#1 SERVICE
RESERVOIR
#2 SERVICE
RESERVOIR
DOUBLE
CHECK
VALVE
PARK CONTROL
SB-3
PISTON B
CHECK VALVE
INLET &
EXHAUST A
PISTON A
INLET
&
EXHAUST
B
EXHAUST
OPERATION - NORMAL SERVICE
RESERVOIRS 1 & 2 CHARGED
When a service application is made by actuating the dual
brake valve, air from the No. 2 delivery circuit is delivered
from the brake valve to the control port, and is stopped at
the closed inlet of valve A. No movement of the internal
components of the SR-1
™
valve takes place. Air from the
No. 1 delivery circuit of the dual brake valve actuates the
service section of the spring brake actuators.
OPERATION - SERVICE APPLICATION WITH
LOSS OF NO. 2 RESERVOIR PRESSURE
In the event air pressure is lost in the No. 2 reservoir, the No.
1 reservoir and the parking control valve will be protected via
the double and single check valves in the air system. A
service application of the foot brake valve in this situation
results in little or no air being delivered from the No. 2 delivery
circuit to the control port of the SR-1
™
valve. No movement
of the SR-1
™
valve internal components takes place. Braking
is assured because the No. 1 service reservoir is protected
by a check valve and the No. 1 delivery circuit of the dual