Section 4: Maintenance; Sensor Removal; Sensor Maintenance - Emerson Rosemount 385 Reference Manual

Reference Manual
00809-0100-3385

Section 4: Maintenance

4.1

Sensor Removal

Remove the sensor from the ball valve as follows:
1.
WARNING
System pressure may cause the sensor to blow out with great force unless care is taken during removal.
Make sure the following steps are adhered to.
2.
3.
CAUTION
Failure to withdraw the sensor completely may result in damage to the sensor when the valve is closed.
4.
WARNING
Before removing the sensor from the ball valve, be absolutely certain that the ball valve is fully closed.
Leakage from the male connector threads may indicate that the male connector is still under pressure.
Leakage through a partially open valve could be hazardous.
5.
Note:
4.2

Sensor Maintenance

4.2.1 Electrode Cleaning
If the electrode is coated or dirty, clean as follows:
1.
2.
3.
Maintenance
Be certain system pressure at the sensor is below 64 psig (542 kPa) before proceeding
with the retraction. It is also recommended that the personnel wear a faceshield and have
a stable footing.
Push in on the sensor using the top of the J-box and slowly loosen the hex nut (B) of the
process end male connector (A). (Refer to Figure 4-2).
When the hex nut is loose enough, slowly ease the sensor back completely until the
retraction stop collar is reached.
Close the ball valve slowly. If there is resistance it may be hitting the sensor. Double check
that the sensor has been retracted to the retraction stop collar.
The Male Connector Body (A) may now be completely unthreaded from the reducing
coupling and the sensor removed for servicing.
With the ball valve fully closed, some residual process fluid may leak from the connectors
MNPT pipe threads. This leakage is normal and to be expected.
Remove the sensor from process as previously instructed in Section 4.1.
Wipe the glass bulb with a soft, clean, lint free cloth or tissue. If this does not remove the
dirt or coating, go to Step 3. (Detergents clean oil and grease; and acids remove scale.)
Wash the glass bulb in a strong detergent solution and rinse it in clean water. If this does
not clean the glass bulb, go to Step 4.
Maintenance
February 2019
13