Instruction Manual

Instruction Manual

D102803X012

249W Sensor

December 2012

When fabricating the cage, maintain a minimum clearance of 1/4‐inch between the displacer and the cage wall. Dirty

or viscous fluids may require a larger clearance. Provide sufficient cage length below the displacer to ensure that the

displacer does not hit the bottom of the cage. The A dimension should be sufficient to permit adequate clearance for

installation and to allow access to isolation valves, etc. When installing the cage, it must be vertically plumb so that the

displacer does not strike the side of the cage.

As shown in figure 5, mount the cage by running equalizing lines between the cage connections and the vessel. A

shutoff or hand valve with a 1‐1/2 inch diameter or larger port should be installed in each of the equalizing lines. Also

install a drain between the cage and shutoff or hand valve whenever the bottom cage line has a fluid‐trapping low

point. On fluid or interface level applications, position the displacer cage so that the cage center is as close as possible

to the center of the fluid level or interface level range being measured. Also consider installing a gauge glass on the

vessel, or on the displacer cage.

Mounting the Sensor on the Process Vessel or Displacer Cage

CAUTION

If inserting the displacer into the vessel or displacer cage before attaching to the displacer rod, provide a means of

supporting the displacer to prevent it from dropping into the vessel or cage and suffering damage.

Install the sensor wafer body on the vessel or displacer cage using the following procedure.

You may attach the displacer to the displacer rod before installing the sensor on the cage or vessel. If so, attach the

displacer to the displacer rod as described in step 1. If the displacer diameter is small enough, you may install a long or

sectionalized displacer through the wafer body after it is positioned on the connecting flange. In this case, install the

displacer in step 4.

1. Place the seal on the connecting flange. To install the displacer, insert the displacer in the vessel or cage. Hold the

wafer body above the connecting flange. Connect the displacer as shown in figure 9, locking the assembly with the

cotter springs provided. If a stem extension is used between the displacer spud and the stem end piece, make sure

the nuts are tight at each end of the stem.

2. To position the wafer body on the connecting flange, insert a stud, with nut, through the connecting flange and one

of the eyelets on the wafer body, as shown in figure 10. Screw a second nut onto the top of the stud to hold the

wafer body in place. This second nut may be removed after the top flange is installed.

3. If you installed the displacer in step 1, go to step 5, otherwise continue with step 4.

4. If installing a long or sectionalized displacer:

a. Remove the torque tube arm assembly and displacer rod from the wafer body.

b. Insert the displacer through the wafer body into the vessel or cage.

c. Reassemble the torque tube arm assembly and displacer rod to the wafer body.

d. Connect the displacer as shown in figure 9, locking the assembly with the cotter springs provided. If a stem

extension is used between the displacer spud and the stem end piece, make sure the nuts are tight at each end of

the stem.