Indiana Code - Labor and Safety - Title 22, Section 22-10-6-9

Compressed air; blasting with compressed air

Sec. 9. (A) Where compressed air is used for blasting or breaking
down the coal, the following shall apply:
(1) Air lines shall be tested to withstand an approximate pressure
of 20,000 pounds per square inch.
(2) Air lines shall be grounded at the compressor and, if possible,
at other low-resistance ground connections along the lines, such as
at borehole casings. They shall not be connected in any way to
tracks, water lines, or other electric power return conductors and
shall be suitably insulated where they cross electric wires or
underneath the track.
(3) Shut-off valves shall be installed every 1,000 feet in all
compressed-air blasting lines and in all branch lines at a point near
the main lines.
(4) Compressed-air blasting lines shall be protected at places

where equipment passes over, under, or adjacent to them.
(5) Steel, copper, or other lines shall not be handled or repaired
when air pressure is in the line.
(6) Air lines shall be examined periodically for kinks or other
weaknesses and replaced immediately when defects are found.
(7) Tubing shall be coiled and uncoiled properly. The part of the
tubing that is affected by frequent coiling and uncoiling shall be
renewed periodically.
(8) Blow-down valves shall not be less than 45 feet from the face
and shall be around a right angle.
(9) Holes for compressed-air tubes shall be within the limits of the
cut, and compressed-air devices shall not be used in improperly
drilled holes.
(10) When blow-down valves are open to discharge the tube, they
shall remain open until time to place the tube in the next borehole.
(11) After breaking down the coal in any one (1) place, the tube
shall be disconnected at once from the air line and not reconnected
until ready to be used in the next place.
(12) When a differential pressure-type tube fails to discharge, the
line leading to the tube shall be disconnected at the blow-down
valve, and the tube shall be dragged by means of the line to an
inactive place, marked with warning signs, and left 1 hour before any
repair work is done thereon.
(13) All persons shall be removed from adjoining working places
where there is danger of breaking through and shall be at a safe
distance around a right angle while coal breaking is in progress.
(14) Breaking coal with compressed air shall be done by certified
shot firers.
(Formerly: Acts 1955, c.168, s.48.)

Last modified: May 27, 2006