Instruction Manual

Instruction Manual
D102803X012
249W Sensor
December 2012
12
The displacer in this unit is a sealed container. If penetrated by process pressure or liquid, the displacer may hold pressure
or hazardous liquid for an extended period. A displacer that has been penetrated by process pressure or liquid may contain:
D pressure as a result of being in a pressurized vessel.
D liquid that becomes pressurized due to a change in temperature.
D liquid that is flammable, hazardous, or corrosive.
Sudden release of pressure, contact with hazardous liquid, fire, or explosion, which might result in personal injury or
property damage, can occur if a displacer that is retaining pressure or process liquid is punctured, subjected to heat, or
repaired.
Handle the displacer with care. Consider the characteristics of the specific process liquid in use.
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
Note
Except for gaskets (keys 12, 13), trouble symptoms peculiar to specific parts are discussed in the following sections. Each section is
specific to these parts. Regardless of location, gasket failure is indicated by leakage in the gasket area. Every time a gasket is
removed, replace it with a new one upon reassembly.
The procedures below apply to the 249W assembly as shown in figure 14. Refer to figure 14 for key number locations.
Removing the Displacer and Stem
WARNING
Refer to the Maintenance WARNING at the beginning of this section.
The displacer (key 4) is a sealed container. If the displacer has been penetrated by process pressure or liquid, it may
hold pressure or hazardous liquid for an extended period.
Process residue buildup on the displacer and stem (key 11) may change displacer weight or displacement. A bent stem
or a dented or corroded displacer can impair performance.
If the displacer rests against the travel stop, appears to be overweight, or causes output drift or other output
inaccuracies, it may have been penetrated by process pressure or liquid. Such a displacer may contain pressure
because it was in a pressurized vessel, may contain process liquid that becomes pressurized due to a change in
temperature, and may contain process liquid that is flammable or hazardous.
WARNING
Sudden release of pressure, contact with hazardous liquid, fire, or explosion, which may result in personal injury or
property damage, can occur if a displacer that is retaining pressure or process liquid is punctured, subjected to heat, or
repaired.
Handle the displacer with care.
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.