33.22—Mode of use.
(a)
A unit or system may be designed for use in connection with percussion and/or rotary drilling in any combination of the following drilling positions: (1) Vertically upward, (2) upward at angles to the vertical, (3) horizontally, and (4) downward.
(b)
Dust-collector units may be designed for use with specific drilling equipment or at specific drilling speeds.