When blow-down valves are opened to discharge the compressed air tube, they shall remain open until time to place the tube in the next borehole.
225 ILCS 705/15.07
When blow-down valves are opened to discharge the compressed air tube, they shall remain open until time to place the tube in the next borehole
Laws 1953, p. 701.
Official source: Illinois General Assembly. Reproduced from public-domain Illinois statutes; confirm against the official source for the current text. Not legal advice.