Ditch Witch JT520, Руководство оператора

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JT520 Operator’s Manual
Prepare - 51
Plan Bore Path
CMW
Recommended Bend Limits
Ditch Witch drill pipes are designed to bend slightly during operation. Slight bending allows for steering and
correcting direction. Bending beyond recommended limits will cause damage that might not be visible. This
damage adds up and will later lead to sudden drill pipe failure.
Pipe Pitch
Ditch Witch drill pipe is tested to bend at a maximum
percent pitch. For JT520 drill pipe, make sure pitch (A)
changes no more than
7% over the full length of each
pipe.
Monitor the pitch of each pipe with the 750/752 Display
on the operator’s console. See page 49.
Bend Radius
JT520 drill pipes have a tested minimum bend radius
of 70’ (21.3 m). This means that a 90-degree bend in
the bore path:
• has a radius (A) of 70’ (21.3 m)
• requires approximately 110’ (33.5 m) of drill
pipe (B).
IMPORTANT: Consider recommended bend limits during any bend, not just during bore entry.
NOTICE: Bending drill pipe more sharply than
recommended will damage pipe and cause failure
over time. Changes in pitch must be
equally
distributed over the length of a pipe. Maximum
changes in pitch within 1-2’ (300-600 mm) of pipe
create sharp bends that will damage pipe.
NOTICE: Bending drill pipe more sharply than
recommended will damage the pipe and cause
failure over time.
• If bend radius is reduced, drill pipe life is
reduced.
• If bend radius is increased, drill pipe life is
increased.
IMPORTANT: Use the charts on the next page to keep bends within safe limits.