D20x22 Series II Navigator HDD
Operation 50-33
T
RAILING
R
OD
W
HILE
P
RE
-R
EAMING
Pre-reaming can be used in difficult drilling conditions when the desired bore diameter cannot be attained with
one pullback. One or more intermediate pre-reams can be made with increasingly larger reamers until reaching
the full diameter. Time can be saved by pulling in additional rod behind each pre-reaming pass. The next size
reamer can then be attached to the rod already in the bore. This process can be repeated as many times as
needed.
Swivel Use
Some swivels, such as a double-eye swivel, can be incorrectly aligned with the reamer. If swivel is not straight
in-line with the reamer, it might not swivel as intended. Instead it could turn like a crank, causing the product
to turn and whip. Before starting rotation of the drill string, it is very important to position the reamer and
product or trailing pipe so that the swivel is extended to be straight in-line with the reamer before pulling in.
WARNING:
Product or trailing drill rod can turn or whip. Death or serious injury could occur if you
are struck by a wrench, entangled, or struck by whipping pipe or product. Ensure swivel is straight
in-line with reamer before pulling back.
Содержание D20x22 Series II
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