Ask X3What does 49 CFR 173.312 (Requirements for shipment of MEGCs) require?
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Based on 49 CFR 173.312, here are the practical requirements for shipping a Multiple-Element Gas Container (MEGC) as a motor-carrier owner:
* Authorized Gases: MEGCs are authorized for liquefied and non-liquefied compressed gases. Each pressure receptacle inside must meet the applicable requirements of §§ 173.301, 173.301b, 173.302b, and 173.304b, and conform to the design, construction, inspection, and testing rules in § 178.75.
* Prohibition on Damage: You cannot offer or accept a hazardous material in a MEGC if it is damaged enough to affect the integrity of the pressure receptacles, structural equipment, or service equipment.
* Requalification Due Dates: You cannot fill or offer for transportation any pressure receptacle in a MEGC if it is due for periodic requalification under 49 CFR part 180, subpart C. (However, receptacles filled and offered *before* their due date can still be transported).
* Pre-Trip Inspections: Before filling and offering a MEGC, you must visually inspect its structural and service equipment. Fix any unsafe conditions first, and make sure all required markings are legible.
* Valves and Shutoffs:
* Except for Division 2.2 permanent gases, every pressure receptacle must have an individual shutoff valve that is tightly closed during transit.
* For Division 2.1, 2.2 liquefied, and 2.3 gases, the manifold must allow each pressure receptacle to be filled separately and kept isolated by a closed valve during transit.
* For Division 2.1 gases, pressure receptacles must be isolated into assemblies of no more than 3,000 liters.
* Filling Limits:
* Do not fill a MEGC above its marked maximum permissible gross mass.
* For non-liquefied compressed gases, do not fill above the lowest marked working pressure of any cylinder.
* For liquefied compressed gases, fill each pressure receptacle separately by weight (one at a time), and ensure filling densities for UN pressure receptacles do not exceed § 173.304b(b).
* Post-Filling Checks: After filling, verify that all closures and equipment are leakproof, and seal every fill opening with a cap or plug.
* Impact Protection: During transport, the MEGC must be protected against lateral and longitudinal impact as well as overturning, as required by § 178.75.