[Code of Federal Regulations] [Title 46, Volume 7] [Revised as of October 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 46CFR197.310] [Page 426] 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. 197.310 Air compressor system. A compressor used to supply breathing air to a diver must have-- (a) A volume tank that is-- (1) Built and stamped in accordance with section VIII, division 1 of the ASME Code with-- (i) A check valve on the inlet side; (ii) A pressure gage; (iii) A relief valve; and (iv) A drain valve; and (2) Tested after every repair, modification, or alteration to the pressure boundaries as required by Sec. 197.462; (b) Intakes that are located away from areas containing exhaust fumes of internal combustion engines or other hazardous contaminants; (c) An efficient filtration system; and (d) Slow-opening shut-off valves when the maximum allowable working pressure of the system exceeds 500 psig.