Coast Guard, DHS § 197.338

the only installed means of retrieving (1) 6 ATA, when used for diving to 300 the closed bell; or fsw; or (ii) A period of time, at least equal to (2) The maximum depth of the dive, 1 hour plus twice the time required to when used for diving operations deeper retrieve the bell from its designed op- than 300 fsw, unless a closed bell meet- erating depth and attach an auxiliary ing the requirements of § 197.330(a) (3), lifesupport system, after an accident (4), and (5) is used; severing the umbilical to the surface (i) Have a minimum pressurization when the umbilical is one of the two rate of 2 ATA per minute to 60 fsw and independent installed means of retriev- at least 1 ATA per minute thereafter; ing the closed bell, each meeting the (j) Have a decompression rate of 1 requirements of paragraph (a)(3) of this ATA per minute to 33 fsw; section. (k) Have an external gage (b) A closed bell that does not meet for each pressurized compartment; the requirements of paragraphs (a)(3), (l) Have a capability to supply (a)(4), and (a)(5) of this section, must be breathing mixtures at the maximum capable of attachment to another rate required by each occupant doing PVHO that— heavy work; and (1) Allows the transfer of personnel (m) Have a sound-powered headset or and diver’s equipment under pressure telephone as a backup to the commu- from the closed bell to the PVHO; nications system required by § 197.328(c) (2) Meets the requirements of para- (5) and (6), except when that commu- graph (a)(3) of this section; nications system is a sound-powered system. (3) Is capable of attachment to a de- compression chamber meeting the re- § 197.334 Open diving bells. quirements of paragraphs (a)(4) and (a)(5) of this section; and Each open must— (a) Have an upper section that pro- (4) Allows the transfer of personnel vides an envelope capable of maintain- and diver’s equipment under pressure ing a bubble of breathing mixture from the PVHO to the decompression available to a diver standing on the chamber. lower section of the platform with his § 197.332 PVHO—Decompression body through the open bottom and his chambers. head in the bubble; (b) Have lifting equipment capable of Each decompression chamber must— returning the occupied open bell to the (a) Meet the requirements of § 197.328; dive location; (b) Have internal dimensions suffi- (c) Have an umbilical; and cient to accommodate a diver lying in (d) Be—(1) Made of corrosion-resist- a horizontal position and another per- ing material; or son tending the diver; (2) Protected against and maintained (c) Have a capability for ingress and free from injurious corrosion. egress of personnel and equipment while the occupants are under pressure; § 197.336 Pressure piping. (d) Have a means of operating all in- Piping systems that are not an inte- stalled man-way locking devices, ex- gral part of the vessel or facility, car- cept disabled shipping dogs, from both rying fluids under exceeding sides of a closed hatch; 15 psig must— (e) Have interior illumination suffi- (a) Meet the ANSI Code; cient to allow visual observation, diag- (b) Have the point of connection to nosis, and medical treatment of an oc- the integral piping system of the vessel cupant. or facility clearly marked; and (f) Have one bunk for each two occu- (c) Be tested after every repair, modi- pants; fication, or alteration to the pressure (g) Have a capability that allows boundaries as set forth in § 197.462. bunks to be seen over their entire lengths from the exterior; § 197.338 Compressed gas cylinders. (h) Have a minimum pressure capa- Each compressed gas cylinder must— bility of— (a) Be stored in a ventilated area;

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(b) Be protected from excessive heat; the dive location or planned pick-up (c) Be prevented from falling; point. (d) Be tested after any repair, modi- (e) A diver-carried reserve breathing fication, or alteration to the pressure gas supply for must be boundaries as set forth in § 197.462; and sufficient to allow the diver to return (e) Meet the requirements of— to the dive location or planned pick-up (1) Part 54 of this chapter; or point from the greatest depth of the (2) 49 CFR 173.34 and 49 CFR part 178, planned dive. subpart C. (f) Oxygen used for breathing mix- tures must— § 197.340 supply. (1) Meet the requirements of Federal (a) A primary breathing gas supply Specification BB-0–925a; and for surface-supplied diving must be suf- (2) Be type 1 (gaseous) grade A or B. ficient to support the following for the (g) Nitrogen used for breathing mix- duration of the planned dive: tures must— (1) The diver. (1) Meet the requirements of Federal (2) The standby diver. Specification BB-N–411c; (3) The decompression chamber, when (2) Be type 1 (gaseous); required by § 197.432(e)(2) or by (3) Be class 1 (oil free); and § 197.434(a) for the duration of the dive (4) Be grade A, B, or C. and for one hour after completion of (h) Helium used for breathing mix- the planned dive. tures must be grades A, B, or C pro- (4) A decompression chamber when duced by the Federal Government, or provided but not required by this sub- equivalent. part. (i) Compressed air used for breathing (5) A closed bell when provided or re- mixtures must— quired by § 197.434(d). (1) Be 20 to 22 percent oxygen by vol- (6) An open bell when provided or re- ume; quired by § 197.432(e)(4) or by § 197.434(c). (2) Have no objectionable odor; and (b) A secondary breathing gas supply (3) Have no more than— for surface-supplied diving must be suf- (i) 1,000 parts per million of carbon ficient to support the following: dioxide; (1) The diver while returning to the (ii) 20 parts per million carbon mon- surface. oxide; (2) The diver during decompression. (iii) 5 milligrams per cubic meter of (3) The standby diver. solid and liquid particulates including (4) The decompression chamber when oil; and required by § 197.432(e)(2) or by (iv) 25 parts per million of hydro- § 197.434(a) for the duration of the dive carbons (includes methane and all and one hour after the completion of other hydrocarbons expressed as meth- the planned dive. ane). (5) The closed bell while returning the diver to the surface. § 197.342 Buoyancy-changing devices. (6) The open bell while returning the (a) A dry suit or other buoyancy- diver to the surface. changing device not directly connected (c) A diver-carried reserve breathing to the exhaust valve of the helmet or gas supply for surface-supplied diving mask must have an independent ex- must be sufficient to allow the diver haust valve. to— (b) When used for SCUBA diving, a (1) Reach the surface. buoyancy-changing device must have (2) Reach another source of breathing an inflation source separate from the gas; or breathing gas supply. (3) Be reached by a standby diver equipped with another source of § 197.344 Inflatable floatation devices. breathing gas for the diver. An inflatable floatation device for (d) A primary breathing gas supply SCUBA diving must— for SCUBA diving must be sufficient to (a) Be capable of maintaining the support the diver for the duration of diver at the surface in a faceup posi- the planned dive through his return to tion;

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