JT520 Operator’s Manual Operation Overview - 41
Drilling
CMW
Drilling
1. Start system. See page 73.
2. Prime drilling fluid pump. See page 73.
3. Engage tracker control if desired. See page 99.
4. Drill first pipe. See page 77.
5. Record bore path. See page 80.
6. Add pipe. See page 78.
7. Drill remaining pipes in pipe box and correct direction (page 79) as necessary.
8. Surface drill head. See page 81.
Backreaming
1. Assemble backream string. See page 82.
2. Start drilling unit and adjust throttle.
3. Set drilling fluid flow. Check that fluid flows through all nozzles. See page 94.
4. Remove pipe from bore. See page 83.
5. Remove pullback device. See page 84.
Backreaming Tips
• Plan backreaming job before drilling. Plan bore path as straight as possible. Check bend limits of
pullback material. Check that appropriate pullback devices are on hand.
• Keep all bends as gradual as possible.
• Drilling fluid quality is a key factor in backreaming success. Contact your Ditch Witch dealer for
information on testing water, selecting additives, and mixing drilling fluid.
• Backreaming requires more fluid than drilling. Make sure enough fluid is used.