Vermeer D20x22 Series II, Operator'S Manual

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50-38 Operation D20x22 Series II Navigator HDD
G
AUGES
- M
ONITOR
D
URING
P
ULLBACK
Monitor gauges during drilling operation to ensure a good pilot bore. Watching the
gauges will help establish a baseline for rotation and thrust/pullback pressures.
Ideally, the pullback pressure will remain low while the reamer mixes drilling fluid
with the soil to form a good slurry flow through the annular space.
Rotation Pressure (1)-- If rotation pressure is spiking, you may be pulling back too
fast for the ground conditions. A rise in rotation pressure can also mean that the
reamer has encountered harder ground.
Thrust/Pullback Pressure (2)-- A steady rise in pullback pressure could indicate a
loss of fluid flow through the annular space, causing the product to become stuck or a
frac-out to occur.
Drilling Fluid Pressure (3)-- The drilling fluid pressure gauge is best used as an indicator that flow is
occurring. Pressure can vary based on flow rates and nozzle sizes used in the tooling. A maximum indication on
the drilling fluid pressure gauge could be an indicator that flow has become restricted. Drilling fluid pressure is
approximately 50% of hydraulic pressure shown on gauge.
D
RILL
R
OD
- R
EMOVE
Refer to “Drill Rods - Remove from Drill String,”
page 30-41.
Rod Box - Changing
Refer to “Rod Box - Remove,”
page 30-35.
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