249W Level Sensor
Instruction Manual
Form 5729
March 2005
10
and be lifted out with the sensor body.
If separating the displacer and
displacer rod, remove the cotter spring
(key 10).
CAUTION
Be careful not to let the displacer slip
and drop into the bottom of the
process vessel or cage, as displacer
damage could result.
1. Support the sensor body (key 1) and the torque
tube arm (key 2). Remove the bolting that holds the
wafer body to the process vessel or displacer cage.
CAUTION
When removing the sensor from a
process vessel or displacer cage, the
displacer may remain attached to the
displacer rod and be lifted out with the
wafer body (key 1) when the wafer
body is removed. If separating the
displacer and displacer rod before
removing the wafer body, remove the
cotter spring (key 10).
Be careful not to let the displacer slip
and drop into the bottom of the
process vessel or displacer cage, as
displacer damage could result.
2. Carefully remove the sensor. If the displacer
comes out with the sensor, be careful not to damage
the displacer or bend the stem when setting the
sensor down.
3. Follow the procedure for replacing the displacer,
displacer rod assembly, cotter spring, stem end
piece, and displacer spud as necessary.
Replacing the Displacer, Cotter Spring,
Stem End Piece, and Displacer Spud
The cotter spring (key 10), the ball on the displacer
rod/driver assembly (key 5), and the stem end piece
or displacer stem connector (key 6) may be either
too worn for a secure connection or so clogged or
corroded that the displacer does not pivot properly.
Replace these parts, as necessary.
CAUTION
If the displacer is to be disconnected
from the displacer rod before being
removed from the process vessel or
displacer cage, provide a suitable
means of supporting the displacer to
prevent it from dropping into the
vessel or cage and being damaged.
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. Support the assembly to
avoid damage to the displacer, displacer stem,
displacer rod/driver assembly, and associated parts.
2. To help support the displacer, install the stem
and stem end piece (or a threaded rod) into the 1/4
inch-28 UNF threaded hole in the displacer spud or
stem connector.
3. Reach the cotter spring, displacer spud, ball end
of the displacer rod/driver assembly, stem end piece,
or displacer stem connector as follows:
4. Remove the cotter spring to free the displacer or
stem end piece from the ball end of the displacer
rod/driver assembly. Lift the displacer or stem end
piece from the ball.
5. Replace worn or damaged parts as necessary.
Return the displacer or stem end piece to the
displacer rod/driver assembly. Install the cotter
spring.
6. Install the sensor and controller/transmitter.
Calibrate the controller/transmitter following the
procedures given in the controller/transmitter
instruction manual.
Replacing the Displacer Rod/Driver
Assembly
The ball on the displacer rod/driver assembly (key 5)
may be either too worn for a secure connection or so
corroded that the displacer does not pivot properly.
Replace the displacer rod/driver assembly, if
necessary.
CAUTION
If the displacer is to be disconnected
from the displacer rod/driver assembly
before being removed from the
process vessel or displacer cage,
