Soil Exit Of Drill Bit; Re-Expanding And Back Towing; Re-Expanding Steps; Define Mud Flow Requirements - XCMG XZ320 Operation Instructions Manual

Manual of XZ320 Horizontal Directional Drill
reject due to super-low success rate.

6 Soil exit of drill bit

Drill bit shall be led to target pit or protrude out of the ground upward. Pay
attention that deformation of auger stem shall be within the minimum
bending radius. Mud pump switch shall be closed instantly once drill bit is
exposed.
Warning： Ask drill operator to close the engine then replace
the drilling tool when using the combination pliers. It is
strictly prohibited to start up the engine when connecting
and replacing drilling rigs.

7 Re-expanding and back towing

Bore can be expanded and materials shall be drawn after finishing
directional drilling.
Warning： All persons shall keep far away from materials and
movable parts which are in installation. Re-expanding or
back towing is not allowed until confirmation that
re-expanding head is installed and relevant persons are far
away from them. Back towing is required firstly until drill bit begins to
enter into the soil then it shall be rotated slowly.

7.1 Re-expanding steps

7.1.1 Selection of re-expanding device: Selection of re-expanding drill bit
may be influenced by dimension of pivot hole, back towing materials and
soil conditions so please contact dealer or factory for details.
Ideal final bore aperture is approximately 1.3 to 1.5 times of pipe diameter
or sum of pipe diameter and 200mm. Suggested expanding aperture is
sum of pipe diameter and 200mm if pipe diameter exceeds 600mm.
Re-expanding head is suggested to be the smaller value of 1.2 to 1.5 times
of outer diameter or sum of outer diameter and 200mm during practice to
form a circular space, remove mud or drilling debris and reduce resistance
of back towing pipes with suitable bending for pipes.

7.1.2 Define mud flow requirements.

7.1.3 Select the back towing device.
7.1.4 Transmitter installed in the re-expander shall be used for
re-correction if re-expanding hole is traced by transmitter.
7.1.5 Set mud flow reasonably.
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