Removing Safe‑Drive 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

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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.
  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 lock inner casing latch (2).
  4. Open the locking latch on outer casing. Grab outer casing with one hand on the handle and the other hand on the wheel.
    1. Fit outer casing over inner casing.
    2. Turn the handwheel clockwise to get the thread of inner casing running through the handwheel.
  5. Rotate outer casing 60° clockwise to lock the bayonet (1) and 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 four M12 nuts on the bolts holding the sensor to Isolation valve using a 19 mm or ¾ in wrench.
  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 Isolation valve handle locking plate.
    1. Close Isolation valve by turning the handle 90°.
      Isolation valve is properly closed when the handle points away from the sensor and the locking plate drops down over the handle.
    2. Open the blow-out valve under 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).
  11. Lift open outer casing locking latch (1), and rotate 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 retractor with 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 ensure 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 Isolation valve with ½ in (M12) bolts and nuts. A lock can be added to 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 retractor with sensor onto a table or similar surface so that the handwheel has space to turn.