Pressure Protection Valve (Pr-4); Shuttle-Type Double Check Valve (Dc-4); Pressure Reducing Valve Rv-3 - PREVOST H3-41 Maintenance Manual

13.10

PRESSURE PROTECTION VALVE (PR-4)

Maintenance and repair information on the pressure protection valve is
supplied in the applicable booklet, found on your Technical Publications
USB flash drive, under reference number Bendix SD-03-2010.
The air system includes two pressure protection valves. One valve is
installed on the manifold block, and insures at all times a minimum
pressure of 70 psi (482 kPa) in the suspension air system in the event that
a pressure drop occurs in either the suspension air system or accessory air
system. This valve is located in the front service compartment beside the
air filter.
The other valve is installed on the accessory air tank, and insures a
minimum pressure of 70 psi (482 kPa) in the accessory air system in the
event that a pressure drop occurs in either the suspension air system or
braking air system (refer to Figure 2 and Figure 3 for accessory air tank
location).
13.11

SHUTTLE-TYPE DOUBLE CHECK VALVE (DC-4)

Maintenance and repair information on the shuttle-type double check valve
is supplied in the applicable booklet, found on your Technical Publications
USB flash drive, under reference number Bendix SD-03-2202.
The double check valve is located on the pneumatic accessories panel in
the front service compartment. In the event of a pressure drop in either the
primary or secondary system, this unit will protect the emergency /parking
brake control valve and the intact portion of the air system from pressure
loss.
13.12

PRESSURE REDUCING VALVE RV-3

The Bendix RV-3 pressure reducing valve is a normally open pressure
control device. The function of the RV-3 valve is to reduce system air
pressure and maintain a constant specified pre-set pressure below that of
system pressure. A pressure reducing valve is installed upstream of the
AHI module (Aftertreatment hydrocarbon injector).
Maintenance and repair information on the pressure reducing valve is
supplied in the applicable booklet, found on your Technical Publications
USB flash drive, under reference number Bendix SD-03-3515.
SECTION 12: BRAKE AND AIR SYSTEM
PA1621 Maintenance Manual All Series | Revised June 2020 23