249W Level Sensor
Instruction Manual
Form 5729
May 2006
14
W0654-1/IL
W0145-1*/IL
DISPLACER ROD
ASSEMBLY
ROTARY SHAFT
TORQUE TUBE
OUTER TUBE END
POSITIONING PLATE
DRIER BEARING
REMOVAL OR INSTALLATION OF POSITIONING PLATE
EXPLODED VIEW OF TORQUE TUBE AND DISPLACER ROD ASSEMBLY
Figure 13. Torque Tube and Displacer Rod Assemblies
The vertical lug fits into a hole in the flange of the
torque tube arm (figure 13). The horizontal lug
(hidden behind the screwdriver in figure 13) fits into
a slot in the outer tube end of the torque tube
assembly (the figure 13 exploded view shows this
lug to the right of the outer tube end).
The positioning plate may be pried away from the
torque tube arm and outer tube end if the displacer
already has been disconnected from the displacer
rod. However, if the displacer is still connected to the
displacer rod, place a screwdriver blade in the slots
of the positioning plate and outer tube end as shown
in figure 13. Slowly turn the positioning plate to
release its lug from the torque tube arm. Then,
carefully turn the plate back to allow the displacer to
come to rest and slip the other lug of the plate from
its slot in the outer tube end.
5. Pull the torque tube assembly and tube end
gasket out of the torque tube arm.
6. Install a new tube end gasket and insert the
torque tube assembly into the torque tube arm as
shown in figure 13. Rotate the torque tube assembly
until its socket mates with the driver member on the
displacer rod assembly and so the outer tube flange
rests against the gasket. With a thumb on the upper
portion of the positioning plate and a screwdriver in
the slots as shown in figure 13, rotate the plate and
press the lug on the plate into the hole in the torque
tube arm.
7. Install the retaining flange and secure it with four
nuts (key 18), being sure to tighten all nuts evenly.
8. Install the sensor and controller/transmitter.
Calibrate the controller/transmitter following the
procedures given in the controller/transmitter
instruction manual.
Replacing the Torque Tube Arm and
Changing the Mounting
Looseness of the driver bearing (key 7), wear on its
knife-edged surface, or a bent, worn, or corroded
displacer rod/driver assembly (key 5) may impair
performance. Be especially sure to check the ball on
the displacer rod.
1. After following the proper procedure to remove
the sensor and the displacer from the process vessel
or displacer cage, move the sensor assembly to a
suitable maintenance area.
CAUTION
Support the sensor assembly to avoid
damage to the displacer, displacer
stem, displacer rod assembly, and
associated parts.
2. Remove the controller/transmitter and displacer
(key 4). Then, remove the hex nuts (key 20) that
hold the torque tube arm (key 2) to the wafer body
(key 1). Separate the torque tube arm from the wafer
body.
3. Follow the proper procedure to remove the torque
tube assembly (key 3).
