MUELLER® DH-5 /EH-5 Drilling Machines
Operating Instructions
5
15. When drilling operation is
completed, turn operating screw
on locking mechanism counter-
clockwise to unlock pivot arm.
collar and retract boring bar to its
drill or pilot drill clears the valve gate.
CAUTION: DO NOT reverse
rotation of ratchet handle when
retracting the boring bar.
16. Close valve being used. Open
bleeder valve located at bottom of
machine to bleed gas from machine
before adapter and machine are
removed from valve.
17.
machine adapter as a unit.
18.
machine adapter and drilling tools
from machine.
19.
foreign material from machine and
give drilling tools a light coat of oil
to protect them from rust. When not
in use, the machine and equipment
furnished with each machine should
be stored in the box furnished. The
machines should be disassembled
periodically, and the boring bar and
machine body thoroughly cleaned
any grit, chips, or other foreign
material that might have possibly
accumulated on the boring bar or
in the body of the machine may be
detected and removed before any
foreign material on either the boring
bar or inside the body will restrict the
reverse travel of the boring bar.
13A. DRILL MAIN – HAND
OPERATED METHOD
Drill the hole by operating the ratchet
handle clockwise and turning the
feed tube and yoke clockwise a
little at a time. Use a light, even feed
at the start, then a heavier feed and
to the balanced pressure design of
these machines, the line pressure
thrust load will not be transmitted to
the boring bar. The special locking
mechanism that locks the boring bar
to the feed yoke prevents the drill
from spiraling into the hole before
the hole is completely drilled. To
prevent over-feeding when drilling
small holes and also when starting
to drill larger holes, apply the feed
by gripping the knurled section of
the feed tube instead of the feed
handles. This will apply a light, even
feed. Feed handles should be used
to apply a heavier feed.
NOTE: When nearing the
completion of the cut, DO NOT
over-feed or the cutting tools may
be forced through before all the
metal is drilled or cut out.
The EH-5 Machine is furnished with
a combination ratchet and crank
handle. When drilling small holes,
the crank handle should be turned
upward and rotated in continuous
circles instead of ratcheting.
14. Continue drilling operation until
pipe is drilled through completely.
This can be determined by the
feel of the feeding mechanism, the
pull on the ratchet handle or by
measuring the advance of the boring
bar. If drilling is not completed,
retract boring bar slightly and ratchet
and feed slowly to remove the
remaining metal a little at a time.
SPECIAL NOTE: In general, the
machines should be lubricated
as described in instruction No.
1. However, due to extreme
conditions in some areas (dust,
sand, etc.) it may be advisable
not to lubricate the feed sleeve or
threaded ports of these machines
since it would tend to increase the
abrasive or wearing action. This
procedure, of course, must be at
the discretion of the operator.
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