46 CFR § 197.456 - Breathing supply hoses.
(a) The diving supervisor shall insure that -
(1) Each breathing supply hose is pressure tested prior to being placed into initial service and every 24 months thereafter to 1.5 times its maximum working pressure;
(2) Each breathing supply hose assembly, prior to being placed into initial service and after any repair, modification, or alteration, is tensile tested by -
(i) Subjecting each hose-to-fitting connection to a 200 pound axial load; and
(ii) Passing a visual examination for evidence of separation, slippage, or other damage to the assembly;
(3) Each breathing supply hose is periodically checked for -
(i) Damage which is likely to affect pressure integrity; and
(ii) Contamination which is likely to affect the purity of the breathing mixture delivered to the diver; and
(4) The open ends of each breathing supply hose are taped, capped, or plugged when not in use.
(b) To meet the requirements of paragraph (a)(3) of this section, each breathing supply hose must be -
(1) Carefully inspected before being shipped to the dive location;
(2) Visually checked during daily operation; and
(3) Checked for noxious or offensive odor before each diving operation.