GILLIG LOW FLOOR, Руководство по обслуживанию

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Air System
Secondary service line may leak out of the primary service at control
pressures up to 20 psi when the primary signal is not present.
balance
Refer to Figure 6-32. The air pressure delivered by the
open inlet valve is also effective on the bottom area of the
relay piston. When air pressure beneath the piston equals
the service air pressure above, the piston lifts slightly and
the inlet spring returns the inlet valve to its seat. The ex-
haust remains closed as the service line pressure balances
the delivery pressure. As delivered air pressure is changed,
the valve reacts instantly to that change, holding the brake
application at that level.
exhaust or release
See Figure 6- 33. When air pressure is released from the
service port and air pressure in the cavity above the relay
piston is exhausted through the brake valve. At the same
time, air pressure beneath the piston lifts the relay piston
and the exhaust seat moves away from the exhaust valve,
opening the exhaust passage. With the exhaust passage
open, the air pressure in the brake chambers is then per-
mitted to exhaust through the exhaust port, releasing the
brakes.
Figure 6-32, R-12DC Balance Position
Figure 6-33, R-12DC Exhaust Position