§ 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.