BENDIX TR-2-TR-3-TR-4 INVERSION VALVE Manual

®
® ™
Bendix TR-2 , TR-3
DELIVERY PORT (2)
CONTROL PORT (3)
™
FIGURE 1 - TR-2 INVERSION VALVE
DESCRIPTION
GENERAL
™ ™
The TR-2 & TR-3 valves are normally open pilot-operated,
inverting, on-off, two-way valves. The TR-4
operated. With normal operating pressure at both supply
and control ports, the delivery port will be exhausted to
atmosphere. 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.
TR-2 ™ INVERSION VALVE
Referring to Figure 1, the TR-2
™
early DD-3 Safety Actuator control systems to apply air
pressure to the emergency diaphragm of the DD-3
actuator's from a protected reservoir as control pressure is
released from the lock mechanism. The TR-2
available in 1 1 / " bulk head mount only.
4
™ ™
& TR-4 Inversion Valves
SUPPLY PORT
EXHAUST
™ valve is lever
™
valve was used primarily in
™
INLET & EXHAUST
VALVE SPRING
BODY
PISTON SPRINGS
RETAINER RING
DIAPHRAGM WASHER
TR-3 ™ INVERSION VALVE
Referring to Figure 2, the TR-3
™
the TR-2 valve, but with a die cast body. Referring to Figure
3, some TR-3
connecting supply pressure to control. The external control
port is permanently plugged in such valves.
TR-4 ™ INVERSION VALVE
Referring to Figure 4, the TR-4
the internal passage connecting supply and control plus a
manual lever control which permits the valve to be locked in
the open position.

OPERATION

™
TR-2 & TR-3
™
When sufficient air pressure is present in the control cavity
valve is to overcome the setting of the piston return spring, the piston
is held away from the inlet valve which is 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
CAP NUT
SEAL RING
MOUNTING NUT
& LOCKWASHER
INLET & EXHAUST
PISTON GROMMET
PISTON
PISTON GROMMET
COVER PLATE
EXHAUST
DIAPHRAGM
CAP SCREW
™
valve is similar in function to
™ valve's have an internal passage in the body
™ valve is a TR-3
™
INVERSION VALVES
VALVE
(SMALL)
(LARGE)
™ valve with
1