(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.
U.S. Department of Labor | Mine Safety and Health Administration (MSHA) | 1100 Wilson Boulevard, 21st Floor | Arlington, VA 22209-3939 www.msha.gov | Telephone: (202) 693-9400 | Fax-on-demand: (202) 693-9401