5
NORMAL SERVICE APPLICATION (FIGURE 7)
During a service brake application, the valve remains in the
lap position. The SR-7
™
valve monitors the presence of air
pressure in both primary and secondary delivery circuits.
FIGURE 7 - NORMAL SERVICE APPLICATION
PARKING (FIGURE 8)
Actuating the park brakes (by pulling the dash valve button
out) exhausts spring brake air pressure through the SR-7
™
valve exhaust port.
FIGURE 8 - PARKING
INLET VALVE SEATED
SECONDARY RESERVOIR
CONSTANT PRESSURE
CONTROL LINE PRESSURE
AIR EXHAUSTS FROM
SPRING BRAKES
CONTROL PORT
MAIN AND CONTROL PISTONS MOVE UP
à
à
à
à
à
à
BALANCE PORT
à
à
à
à
SECONDARY RESERVOIR
CONSTANT PRESSURE
CONTROL LINE PRESSURE
BALANCE PORT - PRIMARY
CIRCUIT PRESSURE
CONTROL PORT - SECONDARY
CIRCUIT PRESSURE
INLET / EXHAUST VALVE SEATED
DELIVERY TO SPRING BRAKES
à
à
à
à
à
à
à
à
à
à
