Removing sensor - PR-23 - PR-23-AC - PR-23-AP - PR-23-GC - PR-23-GP - PR-23-M - PR-23-RP - PR-23-SD - PR-23-W

PR-23 Series User Guide
Document code
IM-EN-PR23
Revision
K
Language
English
Product
PR-23
PR-23-AC
PR-23-AP
PR-23-GC
PR-23-GP
PR-23-M
PR-23-RP
PR-23-SD
PR-23-W
Document type
User guide
  1. Switch off the DTR to cut off power from the sensor. Close wash valve.
    1. Unscrew and remove sensor nameplate.
    2. Loosen the cable gland.
    3. Unscrew the wires.
    4. Remove the sensor cable and cable gland.
      If another in-line sensor is connected to the same DTR, disconnect the loose cable from the DTR and turn on power again.
    5. Check that all safety features are correctly in place. See Safe‑Drive safety features for an overview of the features.
      CAUTION Safety features must be always secured in place in the instructed steps. Not having the safety features in place can result in equipment damage or injury.
  2. Lift up the latch of inner casing to unlock it. Lift inner casing over the sensor head. The latch of inner casing should be slightly to the left.
  3. Rotate inner casing 60 ° clockwise to lock it onto the flange (1), and then lock the inner casing latch (2).
  4. Open the locking latch on the outer casing. Grab outer casing with one hand on the handle and the other hand on the wheel.
    1. Fit the outer casing over the inner casing.
    2. Turn the handwheel clockwise to get the thread of the inner casing running through the handwheel.
  5. Rotate the outer casing 60° clockwise to lock the bayonet (1), and then lock the outer casing latch (2).
  6. Insert the safety pin (1) and lock the safety pin with the safety clip (2).
    WARNING Do not proceed until you have completed this step.
  7. Open and remove the 4 M12 nuts on the bolts holding the sensor to isolation valve using a 19-mm or ¾ in wrench.
    CAUTION Check that the safety latch (see item 3 in Safe-Drive safety features) is engaged.
  8. To remove the sensor from the process, turn the handwheel clockwise until it stops. At this stage about 140 mm (5.5 in) of the thread should stick out from the middle of the wheel.
    WARNING If you detect leaking, revert immediately to the previous step. Do not proceed with removal until the reason for leakage has been cleared and fixed.
  9. Lift up the isolation valve handle locking plate.
    1. Close the isolation valve by turning the handle 90°. Ensure that the locking plate drops down the handle, so that the handle locks to the closed position. See item 3 in the illustration.
      The isolation valve is properly closed when the handle points away from the sensor and the locking plate drops down over the handle.
      CAUTION Use a pin or a lock to secure the isolation valve locking plate in the locked position if there is a chance that the handle is opened by accident.
    2. Open the blow-out valve under the isolation valve for box cleaning to get rid of any process liquid inside the isolation valve.
      WARNING Beware of splashing. Some process liquid will leak out through the small ball valve.
      WARNING Do not proceed until you have completed this step.
  10. Remove the safety clip (1) and pull out the safety pin (2).
    1. Check that the valve handle has pushed the safety latch open, so that it is possible to rotate the outer casing open.
  11. Lift open the outer casing locking latch (1), and rotate the outer casing 60° counterclockwise so that the handle comes up on top (2).
  12. Take a firm hold on the handwheel and the handle, and pull out the retractor with the sensor inside.
    WARNING A firm hold of the tool is essential as the combination of the tool and the sensor is noticeably heavier than retractor alone.
    To secure the isolation valve after the Safe‑Drive tool with the sensor has been removed, you can bolt a standard ANSI 1.5 in 105 lbs blind flange to the isolation valve with ½ in (M12) bolts and nuts. A lock can be added to the isolation valve handle.
    WARNING The sensor tip is hot and may be covered with liquor. It is recommended to rinse the sensor tip and isolation valve with hot water.
  13. Put the retractor with the sensor onto a table or similar surface so that the handwheel has space to turn.
    1. Turn the handwheel counterclockwise to drop the thread, that is, until the outer casing is no longer connected to the parts inside.
    2. Pull off the outer casing.
  14. Open the latch on the inner casing (1).
    1. Keep the sensor steady with one hand and rotate the inner casing counterclockwise with the other hand to unlock the inner casing from the sensor (2).
    2. Pull off the sensor (3).