[Code of Federal Regulations] [Title 30, Volume 1] [Revised as of July 1, 2006] From the U.S. Government Printing Office via GPO Access [CITE: 30CFR57.7806] [Page 366] TITLE 30--MINERAL RESOURCES CHAPTER I--MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR PART 57_SAFETY AND HEALTH STANDARDS_UNDERGROUND METAL AND NONMETAL MINES --Table of Contents Subpart F_Drilling and Rotary Jet Piercing Sec. 57.7806 Oxygen intake coupling. The oxygen intake coupling on jet piercing drills shall be constructed so that only the oxygen hose can be coupled to it.