Emerson Process Management MICRO MOTION T-SERIES - Manual (Page 16)

5 Supplementary information
5.1 Purge the sensor case
If the sensor has purge fittings, they should remain sealed at all times. After a purge plug
has been removed, the sensor case should be purged with argon or nitrogen and resealed.
Purging the case protects internal components. The sensor is purged of all oxygen and
sealed at the factory. If the purge plugs are never removed, it is not necessary to purge or
re-seal the sensor. For more information, contact Micro Motion Customer Service.
If a purge plug is removed from the sensor case, it will be necessary to repurge the case.
CAUTION!
Take all necessary precautions when removing purge plugs. Removing a purge plug
compromises the secondary containment of the sensor and could expose the user to process
fluid.
CAUTION!
Improper pressurization of the sensor case could result in personal injury. Removing a purge
plug will require the sensor case to be repurged with a dry inert gas. Follow all instructions
provided in the case purging procedure.
Prerequisites
Make sure the following are available before beginning the purge procedure:
• Teflon ® tape
• Argon or nitrogen gas sufficient to purge the sensor case
Procedure
1. Shut down the process, or set control devices for manual operation. Before
performing the case purging procedure, shut down the process or set the control
devices for manual operation. Performing the purge procedure while the flowmeter
is operating could affect measurement accuracy, resulting in inaccurate flow signals.
2. Remove both purge plugs from the sensor case. If purge lines are being used, open
the valve in the purge lines.
3. Prepare the purge plugs for reinstallation by wrapping them with 3–5 turns of Teflon
tape.
4. Connect the supply of nitrogen or argon gas to the inlet purge connection or open
inlet purge line. Leave the outlet connection open.
• Exercise caution to avoid introducing dirt, moisture, rust, or other contaminants
into the sensor case.
Supplementary information
12 Micro Motion T-Series