Bendix Commercial Vehicle Systems RV-1 User Manual

Bendix® RV-1™ Pressure Reducing Valve

SD-03-3510

ADJUSTING CAP

LOCK WIRE

DELIVERY

PORT

MOUNTING

HOLES

SUPPLY

PORT

& SEAL

DESCRIPTION

The RV-1™ pressure reducing valve is used to reduce air
pressure and maintain it at a constant specified pre-set
pressure below that of the supply pressure. The pressure
reducing valve has a 1/4" delivery port on the side and a 1/4"
supply port on the bottom. Two 9/32" mounting holes are
cast into the body. A lockwire and seal are optional for a
tamper proof setting.

OPERATION

The pressure setting of the pressure reducing valve is
determined by the setting of the adjusting cap, which exerts
a force on the spring on top of the piston. Compressed air
enters the supply port and passes out the delivery port.
When the air pressure on the bottom of the piston overcomes
the force of the spring on top of the piston, the piston moves
upward and the inlet valve spring forces the inlet valve on its
seat, closing off the supply of air. As the pressure in the
delivery line drops, the force of the spring above the piston
becomes greater than the air pressure below the piston,
allowing the piston to move downward, moving the inlet valve
off its seat and allowing air to pass out the delivery port.

If pressure in the delivery line exceeds the pressure setting
of the pressure reducing valve, the force exerted by the air
pressure below the piston will be greater than the spring
force above the piston. The piston will move up from the
exhaust valve, permitting air to pass by the exhaust valve,

PRESSURE

REGULATING

SPRING

EXHAUST

VENT

PISTON
O-RING

INLET &

EXHAUST

VALVE

CAP

LOCK

NUT

PISTON

VALVE GUIDE

WIRE

INLET VALVE

SPRING

through the hollow piston and valve guide and escape through
the slot in the adjusting cap. When the force of the spring
above the piston overcomes that of the air pressure below
the piston, the exhaust valve is seated, and the pressure in
the delivery line is the same as the setting of the pressure
reducing valve.

Note: The RV-1™ valve should be used in light duty
applications where the supply and delivery pressure is stable
and constant. A rapid or pulsed supply and/or delivery
pressure is not recommended. Please consult Bendix
Engineering with specific application requirements.

OPERATING AND LEAKAGE TESTS

Connect a 120 psi pressure source to the supply port and
connect an accurate test gauge to the delivery. Observe the
gauge with the supply pressure applied, this is the delivery
pressure (the inlet valve is closed). If the pressure delivered
is more than ±5 psi from the pressure indicated on the tag
attached to the valve or vehicle manual, the valve can be
readjusted. Momentarily bleed off some of the delivery
pressure. Discontinue bleed off and recheck the delivery
pressure. The delivery pressure should again be within ±5
psi of the pressure indicated on the tag.

Check for leakage at the adjustment cap base with soap
solution. Leakage should not exceed 100 SCCM or a 1"
bubble in 5 or less seconds. Excessive leakage may indicate
a leaking piston o-ring or inlet/exhaust valve.

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VALVE ADJUSTMENT

If the RV -1™ valve does not deliver as described, and leakage
is minimal, the valve can be readjusted as follows.

1. Remove lockwire (if used).

2. Loosen the cap lock nut while holding the adjusting cap
stationary.

3. Turn the adjusting cap clockwise to increase pressure,
counter clockwise to reduce pressure.

4. The lock nut should be tightened after readjustment, while
holding the adjustment cap stationary .

5. Recheck the delivery pressure as described.

6. Reattach the lockwire and replace the seal if used.

If the RV-1™ valve does not function as described or if
excessive leakage occurs, it is recommended that it be
repaired/replaced with genuine Bendix parts.

PREVENTIVE MAINTENANCE
Important: Review the Bendix Warranty Policy before

performing any intrusive maintenance procedures. A warranty
may be voided if intrusive maintenance is performed during
the warranty period.

No two vehicles operate under identical conditions, as a
result, maintenance intervals may vary. Experience is a
valuable guide in determining the best maintenance interval
for air brake system components. At a minimum, the R V-1
valve should be inspected every 6 months or 1500 operating
hours, whichever comes first, for proper operation. Should
the RV-1™ valve not meet the elements of the operational
tests noted in this document, further investigation and service
of the valve may be required.

WARNING! PLEASE READ AND FOLLOW
THESE INSTRUCTIONS TO AVOID
PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following
general precautions should be observed at all times.

1. Park the vehicle on a level surface, apply the

parking brakes, and always block the wheels.
Always wear safety glasses.

2. Stop the engine and remove ignition key when

working under or around the vehicle. When
working in the engine compartment, the engine
should be shut off and the ignition key should be
removed. Where circumstances require that the
engine be in operation, EXTREME CAUTION should
be used to prevent personal injury resulting from
contact with moving, rotating, leaking, heated or
electrically charged components.

3. Do not attempt to install, remove, disassemble or
assemble a component until you have read and
thoroughly understand the recommended
procedures. Use only the proper tools and observe
all precautions pertaining to use of those tools.

4. If the work is being performed on the vehicle’s air
brake system, or any auxiliary pressurized air
systems, make certain to drain the air pressure from
all reservoirs before beginning

ANY work on the
vehicle. If the vehicle is equipped with an AD-IS
air dryer system or a dryer reservoir module, be
sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s
recommended procedures, deactivate the electrical
system in a manner that safely removes all
electrical power from the vehicle.

6. Never exceed manufacturer’s recommended
pressures.

7. Never connect or disconnect a hose or line
containing pressure; it may whip. Never remove a
component or plug unless you are certain all
system pressure has been depleted.

8. Use only genuine Bendix® replacement parts,
components and kits. Replacement hardware,
tubing, hose, fittings, etc. must be of equivalent

™

size, type and strength as original equipment and
be designed specifically for such applications and
systems.

9. Components with stripped threads or damaged
parts should be replaced rather than repaired. Do
not attempt repairs requiring machining or welding
unless specifically stated and approved by the
vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make
certain all components and systems are restored
to their proper operating condition.

REMOVAL AND INSTALLATION

REMOVAL

1. Block and hold the vehicle by means other than air brakes.

2. Drain the service and isolated reservoirs.

3. Disconnect the air lines from the pressure reducing valve.

4. Loosen the valve mounting bolts and remove the valve.

INSTALLATION

1. Check and clean air lines to valve.

2. Mount the valve securely with bolts and lockwashers.

3. Reconnect the lines to the valve.

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