When Table 1 refers to this section, a cargo containment system must have a permanent inert gas system that:
(a) Maintains the vapor space of the containment system in an inert state by filling the vapor space with a gas that is neither reactive with the cargo nor flammable;
(b) Has a pressure control system that:
(1) Prevents the inert gas system from raising the cargo tank pressure to more than the relief valve setting; and
(2) Maintains at least a 3.5 kPa gauge (approx. 0.5 psig) pressure within the containment system at all times, including cargo discharge;
(c) Has storage for enough inerting gas to replace that normally lost while the tank's atmosphere is maintained in an inert condition (e.g. through tank breathing and relief valve leakage), but in no case an amount less than 5 percent of the tank's capacity when measured with the gas at −18 °C (approx. 0 °F) and a pressure equal to the cargo tank's relief valve setting; and
(d) Has connections for any supplemental gas supply necessary to maintain the inert gas pressure described in paragraph (b) of this section during cargo discharge.
When Table 1 refers to this section, an inert gas system for the containment system must supply inert gas containing no more than 100 ppm water.
When Table 1 refers to this section:
(a) An enclosed space containing a cargo tank must have an inerting system that meets the requirements in § 153.500 applying to the inert gas system of a containment system;
(b) Cargo discharge pumps must be of a type that does not subject the shaft gland to the cargo under pressure or that is submerged; and
(c) The cargo tank's relief valve setting must be no less than 21 kPa gauge (approx. 3 psig).
A containment system carrying carbon disulfide must meet the following:
(a) Each cargo pump must be of the intank type and encased within a cylindrical well that extends from the top of the tank to a point no more than 10 cm (approx. 4 in.) above the bottom of the tank.
(b) [Reserved]
(c) The cargo piping and venting systems must be completely independent of those for other cargo.
(d) Pressure relief valves must be made of type 304 or 316 stainless steel.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 78-128, 47 FR 21209, May 17, 1982]
When Table 1 refers to this section a containment system must meet the following:
(a) Cargo piping and venting systems must be designed so that they can be separated from any containment system endorsed for a cargo not covered by this section.
(b) A cargo tank's relief valve setting must be not less than 21 kPa gauge (approx. 3 psig).
(c) All cargo pumps and valves located below the weatherdeck must be operable from the weatherdeck.
(d) A heat transfer system for the cargo must:
(1) Be independent of other ship service systems, except for other cargo heat transfer systems, and not enter the engine room;
(2) Be totally external to the cargo containment system; or
(3) Be approved by the Commandant (CG-ENG) for use with toxic cargoes.
(e) The cargo must be separated from any bunkers by at least two bulkheads.
(f) A cargo containment system must have a vapor return connection.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 78-128, 47 FR 21209, May 17, 1982; CGD 82-063b, 48 FR 4782, Feb. 3, 1983]
(a) When Table 1 refers to this section, a tankship must have two toxic vapor detectors, at least one of which must be portable, each able to measure vapor concentrations in the range of the time weighted average (TWA) for the cargo. The portable detector may be a direct reading detector tube instrument. These vapor detectors may be combined with those required by § 153.465.
(b) When the toxic vapor detectors required by paragraph (a) of this section are not available and the cargo referenced to this section is transferred through a cargo pumproom, the tankship must meet § 153.336(b).
[CGD 78-128, 47 FR 21210, May 17, 1982]
When Table 1 refers to this section, a tankship must have on board for each crew member:
(a) An emergency escape breathing apparatus (EEBA) approved by the Mining Safety and Health Administration (formerly the Mining Enforcement and Safety Administration) and the National Institute for Occupational Safety and Health, or the tankship's flag administration.
(b) Where the emergency escape breathing apparatus does not protect the eyes from vapors, a set of goggles that either:
(1) Meet the specifications of ANSI Practice for Occupational and Educational Eye and Face Protection, Z-87.1(1979); or
(2) Are approved by the tankship's flag administration.
[CGD 78-128, 47 FR 21210, May 17, 1982]
When Table 1 refers to this section, a containment system must meet the following:
(a) Except as provided in paragraphs (b) and (c) of this section, a cargo containment system must be made of:
(1) Stainless steel other than types 416 and 442; and
(2) Steel.
(b) Except as provided in paragraph (c) of this section, gaskets must be composites of spirally wound stainless steel and Teflon or similar fluorinated polymer.
(c) The Commandant (CG-ENG) approves a cargo containment system using materials other than those described in this section for alkylene oxides on a case by case basis if:
(1) The person wishing to have the containment system approved completes any tests prescribed by the Commandant (CG-ENG); and
(2) The Commandant (CG-ENG) approves the results of the tests and the material for use with alkylene oxides.
(d) The following materials are generally found unsatisfactory for gaskets, packing, insulation, and similar uses in alkylene oxide containment systems and would require extensive testing as described in paragraph (c) of this section before being approved:
(1) Neoprene or natural rubber if it might be in contact with the alkylene oxide.
(2) Asbestos or asbestos mixed with other materials such as with many common insulations, packing materials, and gasket materials.
(3) Materials containing oxides of magnesium, such as mineral wools.
(e) The tank's relief valve setting must not be less than 21 kPa gauge (approx. 3 psig).
(f) If the containment system is equipped with a cooling system, the cooling system must:
(1) Not compress the cargo; and
(2) Regulate the cargo temperature automatically and allow manual regulation.
(g) The cargo piping system must:
(1) Comply with Part 38 of this chapter;
(2) Be completely separate from all other systems;
(3) Be assembled from valves, fittings, and accessories having a pressure rating of not less than 1030 kPa gauge (approx. 150 psig) (American National Standards Institute); and
(4) Have no threaded joints.
(h) The cargo containment system vapor space and each space listed in paragraphs (k) and (l) of this section must have continuous monitoring of oxygen concentration or have an arrangement to enable sampling with a portable oxygen analyzer.
(i) Valve disks or disk faces, seats, and other wearing valve parts must be made of stainless steel containing no less than 11 percent chromium.
(j) The venting system must be independent of other containment or tankship systems.
(k) When a cargo tank is in an enclosed space, the space must have:
(1) An inert gas system meeting the requirements that apply to the inert gas system of a containment system in § 153.500, or
(2) A forced ventilation system meeting the requirements that apply to a cargo handling space ventilation system in § 153.312.
(l) Cofferdams, cargo tanks, double bottom spaces, void spaces and other enclosed spaces adjacent to an integral cargo tank must have an inert gas system meeting the requirements that apply to the inert gas system of a containment system in § 153.500.
(m) An intank pump or inert gas displacement must be used to discharge cargo.
(n) The cargo discharge piping system must have a remotely actuated quick closing shutoff valve that meets § 153.284 at the cargo transfer hose connection.
(o) Cargo hose must:
(1) Have the specific approval of the Commandant (CG-ENG) for use in alkylene oxide transfer; and
(2) Be marked “For Alkylene Oxide Transfer Only”.
(p) All exposed parts of the cargo containment system above or on the deck, such as tank domes, cargo piping, and loading manifolds, must be covered by a water spray system that:
(1) Operates automatically in a fire involving the cargo containment system;
(2) Has at least two remote manual actuators, one in each emergency shutdown station required by § 153.296; and
(3) Covers the area of application with a uniform spray of
0.175 l/m2 sec (0.0043 gal/ft2 sec).
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 78-128, 47 FR 21210, May 17, 1982; CGD 82-063b, 48 FR 4782, Feb. 3, 1983; CGD 82-063b, 48 FR 39629, Sept. 1, 1983; CGD 81-078, 50 FR 21174, May 22, 1985; USCG-2014-0688, 79 FR 58284, Sept. 29, 2014]
(a) A containment system carrying liquid sulfur must have:
(1) A cargo tank ventilation system that:
(i) Maintains the H2S vapor concentration below 1.85 percent by volume; and
(ii) Prevents sulfur buildup within itself; and
(2) An alarm system designed to operate when the ventilation system blower fails.
(b) The void spaces around a cargo tank that carries liquid sulfur must be oil tight.
(c) A cargo tank that carries liquid sulfur and the void spaces surrounding the tank must have connections for sampling vapor.
When Table 1 refers to this section:
(a) Each containment system loading and discharge connection must have a spray shield;
(b) Each cargo containment system must be separated from bunkers by double walls, such as a cofferdam and piping tunnels; and
(c) Each vessel must have on board a means to determine whether cargo has leaked into the spaces adjacent to a cargo containment system.
When Table 1 refers to this section, a tankship's shell plating must not be a part of the cargo tank.
[CGD 78-128, 47 FR 21210, May 17, 1982]
(a) Except as prescribed in paragraphs (b) and (c) of this section, containment systems carrying sulfuric acid, oleum, or contaminated sulfuric acid are approved by the Commandant (CG-ENG) on a case by case basis.
(b) A containment system carrying sulfuric acid may be:
(1) Made of unlined steel if the cargo composition is between 70 and 80 or between 90 and 100 percent acid by weight;
(2) Lined with lead if the cargo composition does not exceed 96 percent acid by weight; or
(3) Lined with natural rubber or neoprene if the cargo composition does not exceed 51 percent acid by weight.
(c) A containment system for oleum may be of unlined steel if the concentration of free sulfur trioxide in the oleum exceeds 20 percent by weight.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]
(a) A containment system that carries hydrochloric acid must be lined with:
(1) Natural rubber;
(2) Neoprene; or
(3) A material approved for hydrochloric acid tanks by the Commandant (CG-ENG).
(b) Containment systems for contaminated hydrochloric acid are approved by the Commandant (CG-ENG) on a case by case basis.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 82-063b, 48 FR 4781, Feb. 3, 1983]
A phosphoric acid containment system must be:
(a) Lined with natural rubber or neoprene;
(b) Lined with a material approved for phosphoric acid tanks by the Commandant (CG-ENG); or
(c) Made of a stainless steel that resists corrosion by phosphoric acid.
“Phosphoric acid”, as defined in § 153.2, includes phosphoric acid, superphosphoric acid, and aqueous solutions of phosphoric acid.
[CGD 73-96, 42 FR 49027, Sept. 26, 1977, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983; CGD 88-100, 54 FR 40042, Sept. 29, 1989]
A containment system that carries nitric acid (less than 70 percent) must be of stainless steel that resists corrosion by nitric acid.
(a) The carriage temperature of octyl nitrates must be maintained below 100 °C (212 °F) in order to prevent the occurrence of a self-sustaining exothermic decomposition reaction.
(b) Octyl nitrates may not be carried in a deck tank unless the tank has a combination of insulation and a water deluge system sufficient to maintain the tank's cargo temperature below 100 °C (212 °F) and the cargo temperature rise at below 1.5 °C(2.7 °F)/hour, for a fire of 650 °C (1200 °F).
[CGD 88-100, 54 FR 40042, Sept. 29, 1989, as amended by CGD 92-100, 59 FR 17028, Apr. 11, 1994; CGD 94-900, 59 FR 45139, Aug. 31, 1994]
If a cargo listed in table 1 of this part refers to this section, temperature sensors must be used to monitor the cargo pump temperature to detect overheating due to pump failures, when carrying that cargo.
[CGD 94-900, 59 FR 45139, Aug. 31, 1994]
When Table 1 refers to this section, the air inlet to the pressure-vacuum valve for the cargo tank must be located at least 2m (approx. 6.6 ft) above the weatherdeck.
[CGD 78-128, 47 FR 21210, May 17, 1982]