TOFp Systems Procedure:
pVPD Removal


   Description:
This is the procedure to remove an entire pVPD (structure, PMT Assys, electronics) from its present mounting location. This procedure is the same for the removal of the East or West pVPD, as the two are identical.
   Related Documentation:
  1. TOFp Glossary
  2. pVPD CADD Drawings
  3. pVPD Installation Procedure
   Requirements:
  1. Notification & Approval of TOFp Group
  2. Notification & Approval of STAR Operations Group
  3. Two (2) People to perform this work
  4. STAR Area Manlift Training for at least one worker.
  5. STAR Magnetic Field is OFF
  6. CTB High Voltage Supply is OFF.

    7. TOOLS:
  7. Large Ladder
  8. Manlift
  9. Several wrenches for 1/4-20 hex bolts
  10. Several wrenches for XX-XX hex bolts
  11. 6-32 Nutdriver
  12. Cable tie snips and Cable ties
   Procedure:
    ACCESS:
  1. Make sure STAR Magnet is OFF.
  2. Make sure CTB HV Supply is OFF.
  3. Position manlift to face due south(north) at the steel floor rails on the East(West) side of STAR for access to East(West) pVPD.
  4. Position Large Ladder in front of manlift, to allow access to side of pVPD opposite to that accessible from manlift. Use ropes to secure ladder to some solid object nearby for support.
  5. One worker rises to height of pVPD in manlift, and extends floor to within ~4" of pVPD. Insure the manlift floor cannor rock or sway by enough that the manlift railings strike the pVPD, I-beam, or anything else.
  6. The other worker climbs the ladder.

    7. CABLING REMOVAL:
  7. Locate the three detector assemblies (~3" O.D. black steel cylinders wrapped in kapton tape). Carefully remove the BNC cables (Black jacket) from the rear of each detector assembly.
  8. Carefully remove the SHV cables (Red jacket) from the rear of each detector assembly.
  9. Remove Threshold Bus Cable from feedthough connection at FEE box.
  10. Remove LV Bus Cable from feedthough connection at FEE box.
  11. Carefully remove 6 signal cables from 'rear' face of FEE box
  12. Locate Thermocouple (small brown 2conductor) wire. Use 6-32 nutdriver to open FEE box (from below). Carefully snip the cable tie holding this thermocouple wire inside the FEE box. Pull this wire out of the FEE box.
  13. Remove *only* those cable ties needed to free cables from pVPD structure.
  14. Professionally stow, using appropriately-located cable ties, the dangling cables so that they are our of the way and immune to subsequent damage.

    15. UPPER STRUCTURE REMOVAL:
  15. Locate the 4 o'clock Detector Assembly, and the Four (4) 1/4-20 hex bolts that pass through the Delrin Front and Back Plates and through the "Aluminum Boat". The 4 o'clock Detector Assembly is hose-clamped to this Aluminum Boat - do *not* loosen or remove these hose clamps.
  16. Grasp the Detector Assembly, lightly loosen these four bolts, and slide the Boat/Det Assy outwards along the slots in the Delrin Front and Back Plates.
  17. Retighten these four bolts so that this Boat is securely held by the Delrin plates again.
  18. Repeat previous three steps on the 8 o'clock Detector Assembly.
  19. The Upper Structure lifts vertically off of the baseplate, taking the detector assemblies with them. Locate the Four (4) angle brackets that join the baseplate to the Delrin Front and Back Plates.
  20. Locate the Eight (8) 1/4-20 Hex Bolts that pass vertically through the Baseplate and any of these angle brackets.
  21. Use wrenches to remove *only* these eight bolts.
  22. While being spotted by the worker on the ladder, Lift the Upper Structure straight up and into a secure location on the floor of the manlift.

    23. BASE PLATE REMOVAL:
  23. Use the XX-XX wrenches to loosen *only* to 'hand-tightness' the Bolts through each of the Four (4) I-Beam Clamps. Do not loosen all the way and do not remove these bolts.
  24. Locate and remove the single (1) 1/4-20 hex bolt that passes through the I-beam and Base Plate.
  25. While being spotted by the worker on the ladder, hold the base plate up against the bottom of the I-beam, and rotate the four clamps so that each no longer registers on the lip of the I-beam. (No need to remove these bolts).
  26. Lower Base Plate and put in a secure location on the floor of the manlift. Remember that there are fragile electronics in the FEE box.
  27. Lower manlift, unlash Ladder, and remove each in appropriate locations.
  28. Carefully stow Base Plate/FEE box in safe location.
  29. (Both workers) Carefully stow Upper Structure/Det Assys in safe location.
   Testing:
N/A
   Completion:
  1. Notify STAR Operations that job is complete.
  2. Contact TOFp Control to inform that procedure is complete, and with any end-of-procedure comments that are necessary.
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