Preparing To Drill; Hose Connection; Setting-Up The Rig; Drilling - Atlas Copco SECOROC COP 34 Manual

Preparing to drill

Hose connection

Connecting and securing the air hoses.
For a compressed air system to be effi cient, reliable and economic,
there must be:
suffi cient compressed-air
capacity (volume and pressure);
minimal pressure loss
between the compressor and
the hammer;
minimal air leakage between
couplings.
This can be realized by ensuring
that:
the correct size of compres-
sor is selected;
the correct hose size is used
between the compressor and
the hammer;
there is no leakage in hose
connections between the com-
pressor and hammer.
DANGER
Compressed-air hoses between the compressor and the drill rig
must be secured by means of an external or internal safety wire, which
must be fastened safely to the drill rig. If the DTH hammer is to work
at pressures above 10 bar (145 psi), any local regulations regarding air
hoses and couplings must be strictly observed.
Always check that hoses, hose nipples and hose clamps are not
damaged, and that they are properly tightened and secured.
CAUTION
Always check the condition of drill string components. Bent or worn
pipes can cause damage and excessive wear to the hammer and rig.

Setting-up the rig

Before drilling with the DTH hammer, the rig must be set-up correctly
in order to give stability and safety. If this is not done, the effects of
feed force and rotation torque can cause the rig to move. This will have
a negative effect on drilling, especially when
drilling deep, straight holes.
When setting up a drill wagon or crawler
drill rig, a stable three-point set-up must be
obtained, with the weight of the rig distributed
between the base of the feed beam and the
two rear corners of the rig. It is of the utmost
importance that the rear loading points are
as far to the rear of the rig as possible, with
most of the rig weight being loaded on to the
base of the feed.
When drilling in soil or other non-consoli-
dated formations, the weight of the rig must
not be loaded on to the feed near the mouth
of the hole, since this could easily cause the
hole to cave-in. Instead, the load should be
distributed some distance to either side of
the hole. Suitable support can be obtained
by placing a sturdy U-beam under the base
of the feed beam, and supporting the beam
on planks at both ends. A two inch (50
mm) plank should then be placed inside the
U-beam to prevent mechanical chatter and
damage to the base of the feed beam.
If the rig is wheel-bound, it should be raised off the ground completely
using the jacks, so that all wheels are clear of the ground.
DANGER
The rig must be set-up correctly in order to give stability and safety.
If this is not done, the effects of feed force and rotation torque can cause
the rig to move or even to overturn. This can incur the risk of serious or
fatal injury as well as damage to the drill rig and equipment.
WARNING
Heavy lift. Take care when handling the hammer.
The hammer and its internal components are heavy and diffi cult
to handle, especially in the case of the larger hammers.
When lifting using mechanical
lifting equipment, sling the
hammer as shown in the fi g.
Alternatively, a lifting-eye cou-
pling can be screwed on to the
top sub.
Transportation. Do not let
the hammer lie unsecured on a vehicle or drill rig. Al ways secure the
hammer for transportation.
WARNING
Always wear goggles during drilling!
The exhaust air from the hammer (and also from the top sub if a
unit for extra fl ushing is fi tted) has a very high velocity. Objects such as
small stones, drill cuttings, sand, earth and oil residue that are entrained
in the fl ushing air can cause serious injury to unprotected eyes. Pay
special attention to this danger during collaring, when a top sub with
extra fl ushing is in use, and when the hammer is fed through the drill
steel support or down into the hole.

Drilling

Rotation to the right

DTH hammers must be rotated to the RIGHT (clock wise) during drill-
ing, since the driver chuck and top sub are threaded into the cylinder
with RIGHT-HAND THREADS.
Rotation must always be to the right when the hammer is operating.
Left-hand rotation (or no rotation) will cause the driver chuck to loosen,
which could mean losing the drill bit (or even the entire hammer) down
the hole.
The drill string should be rotated to the right
even when the hammer is not operating. For
example, this should be done when cleaning
the drill hole and when lifting up the drill
string. It can be said that rotation to the
right should be switched on as long as
other operations are in progress with the
hammer in the hole. The risk of the drill bit
working loose should also be considered
when breaking the joints between drill pipes.
When adjusting the breaking wrenches,
bear in mind that the drill string must not
be rotated anti-clockwise any more than is
absolutely necessary.
IMPORTANT!
Always switch on rotation to the right before starting the feed or
hammer.
Let the hammer rotate to the right (clockwise) even during lifting or
lowering of the hammer.
Do not switch off rotation to the right until all other functions have
been switched off.
WARNING
Take great care when jointing drill pipes. Make sure there is no danger
of your fi ngers being pinched or clothing being entangled when the drill
string is rotated.
When a pipe wrench is used during jointing, there is a risk of the
wrench fl ying off and causing injury when rotation is applied.
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