46 CFR § 153.530 - Special requirements for alkylene oxides.
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
(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.
(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.
(1) An inert gas system meeting the requirements that apply to the inert gas system of a containment system in § 153.500, or
(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;
(3) Covers the area of application with a uniform spray of