[Code of Federal Regulations] [Title 46, Volume 7] [Revised as of October 1, 2004] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR197.326] [Page 427] TITLE 46--SHIPPING CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PART 197_GENERAL PROVISIONS--Table of Contents Subpart B_Commercial Diving Operations Sec. 197.326 Oxygen safety. (a) Equipment used with oxygen or oxygen mixtures greater than 40 percent by volume must be designed for such use. (b) Oxygen systems with pressures greater than 125 psig must have slow-opening shut-off valves except pressure boundary shut-off valves may be ball valves.