Ask X3What does 49 CFR 173.301b (Additional general requirements for shipment of UN pressure receptacles) require?
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Based on 49 CFR 173.301b, here are the practical requirements for motor-carrier owners shipping UN pressure receptacles:
* Condition before filling: Do not fill or offer a receptacle for transport if it is damaged enough to affect its integrity or service equipment. Prior to filling, examine the service equipment to ensure it is in good working condition, and make sure all required markings are legible.
* Material compatibility: Gases and gas mixtures must be compatible with the receptacle and valve materials, as prescribed in the specified ISO standards for metallic and non-metallic materials.
* Changing gas service: A refillable receptacle cannot be filled with a different gas than it previously held unless the necessary change-of-service operations are performed in accordance with ISO 11621.
* Valves and shut-offs: Except for Division 2.2 permanent gases, each receptacle must have an individual shut-off valve that is tightly closed during transit. Valves must meet specific ISO standards depending on whether they are standard, quick-release, or non-refillable.
* Valve damage protection: Valves must be protected against accidental release using an approved method, such as recessed necks with plugs/caps, conforming valve caps (with vent holes), shrouds or guards, inherent valve strength, frames/bundles, strong outer packaging, or self-closing valves with inherent protection.
* Pressure relief devices: Each receptacle must have an individual pressure relief device (per § 173.301(f)). For bundles or manifolded horizontal cylinders, the set-to-discharge pressure must be based on the lowest marked pressure of any cylinder in the unit.
* Pyrophoric gases: Receptacles used for pyrophoric or flammable mixtures containing more than 1% pyrophoric compounds must have valve outlets equipped with gas-tight plugs or caps (with matching threads). For manifolded bundles, each individual receptacle valve must be closed, and the manifold valve outlet must have a gas-tight plug or cap.
* Hydrogen bearing gases: Hydrogen-bearing or other embrittling gases must use steel UN pressure receptacles or UN composite pressure receptacles with a steel liner bearing an “H” mark.
* Underwater composite cylinders: Composite cylinders certified to ISO-11119-2 or ISO-11119-3 cannot be used for underwater applications unless they are manufactured for underwater use and marked “UW.”
* Outer packaging: When strong outer packaging is required, receptacles must be protected from shifting.