20
Air System
Pressure Protection Valves
Pressure protection valves (see Figure 6-20) are used to limit the
amount of air pressure taken from the air brake system to oper-
ate auxiliary devices. The pressure protection valves are mount-
ed on the accessory air tank delivery ports. They are used to
supply the air suspension, seat, and air-operated doors. If a leak
occurs in any of the systems supplied by the pressure protection
valves, the PPV will automatically block the flow to the leaking
accessory system when the pressure in the accessory tank drops
to around 70 psi. This will protect the brake system by maintain-
ing at least 70 psi in the primary and secondary air reservoirs.
Figure 6-19, Pressure
Regulator
Pressure Regulator
This adjustable valve (Figure 6-19) is used to limit air pressure delivered to
the brake interlock system to about 23 psi. This prevents damage to brake
components caused by repeated brake application by the interlock system
at full brake system pressure.
Figure 6-20, Pressure
Protection Valve
Summary of Contents for LOW FLOOR
Page 18: ...Specifications 18...
Page 58: ...Preventive Maintenance 58...
Page 110: ...Engine 110...
Page 138: ...Transmission Driveline Rear Axle 138...
Page 182: ...Suspension 182...
Page 260: ...Air System 260...
Page 420: ...Electrical System 420 Deutsch DT Series Connectors...
Page 421: ...Electrical System 421...
Page 422: ...Electrical System 422 Deutsch HD 10 Series Connectors...
Page 423: ...Electrical System 423...
Page 424: ...Electrical System 424 Deutsch HD 30 Series Connectors...
Page 425: ...Electrical System 425...
Page 442: ...Heating Air Conditioning 442...
Page 492: ...Body and Interior 492 Figure 11 33 USSC Seat Assembly...
Page 493: ...Body and Interior 493 Figure 11 34 USSC Seat Suspension Assembly...
Page 495: ...Body and Interior 495 Figure 11 37 Seat Air Connections...