Ditch Witch JT20 - Manual (Page 105)

Conduct a Bore - 104
JT20 Operator’s Manual
Backream
CMW
®
Assemble Backream String
1. Select backreaming devices. See “Backreamers” on page 126.
2. Determine fluid rate requirements and install appropriate nozzles to provide sufficient flow. See
“Backream Fluid Requirements” on page 127 and “Nozzles” on page 124.
3. Attach backreamer to beacon housing if tracking backream.
4. Install beacon, following beacon instructions for:
• battery replacement
• beacon positioning
5. Install beacon housing lid. See page 125.
6. Follow beacon instructions to check beacon operation.
7. Follow tracker instructions to calibrate beacon.
8. Use quick wrenches to attach transition sub to drill pipe string.
9. Use quick wrenches to attach backreamer/beacon housing assembly to transition sub.
10. Attach additional pullback devices or product to end of backreamer/beacon housing assembly.
Begin Backream
1. After backream assembly is attached to pipe, tracker operator should:
• leave pit and stand away from the exposed drill string.
• if using tracker control, turn on tracker to enable drilling unit thrust/pullback and rotation.
• if not using tracker control, communicate to drill operator that backream string is clear.
2. Turn on drill fluid and pressurize drill pipe. Verify that jets are open.
3. Without rotating, slowly pull back until reamer contacts bore hole opening. Do not lodge reamer in
hole.
4. Begin slow rotation and pullback.
5. Increase drilling fluid flow and rotation as the backream string enters the ground.
6. If tracking backream, tracker operator may continue tracking when the backream string is no longer
visible.