Section 197.310 - Air compressor systemA 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;(iii) A relief valve; and(2) Tested after every repair, modification, or alteration to the pressure boundaries as required by § 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.