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ManualsBrandsBendix Commercial Vehicle Systems ManualsEquipmentTR-3 INVERSION VALVES 8/11

SD-03-4650

Bendix

TR-2

™

& TR-3

™

Inversion Valves

DESCRIPTION

GENERAL

The Bendix

TR-2

™

& TR-3

™

valves are normally open,

pilot-operated, inverting, on-off, two-way valves. As control

pressure is reduced—to the point that the piston return

spring or springs overcomes the force on the control

piston—the valve will deliver full supply pressure at the

delivery port.

BENDIX

TR-2

™

INVERSION VALVE

Referring to Figure 1, the Bendix TR-2 valve was used

primarily in early Bendix

DD-3

™

safety actuator control

systems. It applied air pressure to the emergency

diaphragm of the DD-3 actuators from a protected reservoir

as control pressure is released from the lock mechanism.

The TR-2 valve is available in 1-1/4" bulk head-mount only.

BENDIX

TR-3

™

INVERSION VALVE

Referring to Figure 2, the Bendix TR-3 valve is similar in

function to the Bendix TR-2 valve, but with a die cast body.

Referring to Figure 3, some TR-3 valves have an internal

passage in the body connecting supply pressure to control.

The external control port is permanently plugged in such

valves.

OPERATION

BENDIX TR-2 & TR-3 INVERSION VALVES

When sufﬁ cient air pressure is present in the control cavity

to overcome the setting of the piston return spring, the

piston is held away from the inlet valve which is, in turn,

held closed by the inlet valve return spring. The delivery

lines are vented to atmosphere through the hollow exhaust

stem of the piston. When air pressure in the control cavity

falls to a predetermined pressure—or is vented from the

control cavity—the piston spring forces the piston against

the inlet valve, closing the exhaust passage in the hollow

piston stem. Further travel of the piston opens the inlet

valve allowing the passage of air past the open inlet valve,

and out the delivery port.

FIGURE 1 - BENDIX

TR-2

™

INVERSION VALVE

CONTROL PORT (3)

CAP SCREW

DELIVERY PORT (2)

CAP NUT

SEAL RING

PISTON

MOUNTING NUT

& LOCKWASHER

INLET & EXHAUST

VALVE

PISTON GROMMET

(SMALL)

PISTON GROMMET

(LARGE)

EXHAUST

DIAPHRAGM

COVER PLATE

DIAPHRAGM WASHER

RETAINER RING

PISTON SPRINGS

BODY

INLET & EXHAUST

VALVE SPRING

SUPPLY PORT

EXHAUST

Summary of content (4 pages)

PAGE 1
SD-03-4650 Bendix® TR-2™ & TR-3™ Inversion Valves SUPPLY PORT CAP NUT SEAL RING INLET & EXHAUST VALVE SPRING MOUNTING NUT & LOCKWASHER INLET & EXHAUST VALVE DELIVERY PORT (2) BODY PISTON GROMMET (SMALL) CONTROL PORT (3) PISTON PISTON SPRINGS PISTON GROMMET (LARGE) RETAINER RING EXHAUST COVER PLATE EXHAUST DIAPHRAGM DIAPHRAGM WASHER CAP SCREW FIGURE 1 - BENDIX® TR-2™ INVERSION VALVE DESCRIPTION GENERAL BENDIX® TR-3™ INVERSION VALVE Referring to Figure 2, the Bendix TR-3 valve is similar in funct
PAGE 2
1/4” P.T. SUPPLY O-RING INTERNAL PASSAGE CAP VALVE SPRING VALVE STOP INLET & EXHAUST VALVE 1/8” P.T. CONTROL 1/4” P.T. DELIVERY O-RING SHIM PISTON O-RING DIAPHRAGM RETAINER EXHAUST NUT DIAPHRAGM PISTON SPRING EXHAUST FIGURE 2 - BENDIX® TR-3™ INVERSION VALVE The Bendix® TR-3™ valve, with the internal control passage functions the same as described in the previous paragraph. The only exception is that the control pressure is always the same as the supply pressure.
PAGE 3
NOTE: In the Bendix® TR-3™ valve shown in Figure 3, control pressure is reduced by decreasing supply air pressure because of the internal passage connecting supply and control. ® If the Bendix TR-3 inversion valve does not function as described—or leakage is excessive—it is recommended that it be replaced with a new valve or remanufactured unit. The Bendix TR-2 valve can be serviced with a maintenance kit or replaced with a new or remanufactured valve.