Section 173.312 - Requirements for shipment of MEGCs(a)General requirements.(1) Unless otherwise specified, a MEGC is authorized for the shipment of liquefied and non-liquefied compressed gases. Each pressure receptacle contained in a MEGC must meet the requirements in §§ 173.301 , 173.301b , 173.302b and 173.304b , as applicable.(2) The MEGC must conform to the design, construction, inspection and testing requirements prescribed in § 178.75 of this subchapter.(3) No person may offer or accept a hazardous material for transportation in a MEGC that is damaged to such an extent that the integrity of the pressure receptacles or the MEGC's structural or service equipment may be affected.(4) No person may fill or offer for transportation a pressure receptacle in a MEGC if the pressure receptacle or the MEGC is due for periodic requalification, as prescribed in subpart C to part 180 of this subchapter. However, this restriction does not preclude transportation of pressure receptacles filled and offered for transportation prior to the requalification due date.(5) Prior to filling and offering a MEGC for transportation, the MEGC's structural and service equipment must be visually inspected. Any unsafe condition must be corrected before the MEGC is offered for transportation. All required markings must be legible.(6) Except for Division 2.2 permanent gases, each pressure receptacle must be equipped with an individual shutoff valve that must be tightly closed while in transit. For Division 2.1, Division 2.2 liquefied gases and 2.3 gases, the manifold must be designed so that each pressure receptacle can be filled separately and be kept isolated by a valve capable of being closed during transit. For Division 2.1 gases, the pressure receptacles must be isolated by a valve into assemblies of not more than 3,000 L.(b)Filling.(1) A MEGC may not be filled above its marked maximum permissible gross mass. Additionally, MEGCs must be filled in accordance with the following: (i) A MEGC being filled with non-liquefied (permanent) compressed gas may not be filled to a pressure greater than the lowest marked working pressure of any cylinder (pressure receptacle).(ii) An MEGC being filled with a liquefied compressed gas must have each pressure receptacle filled separately by weight and must be filled by a means to ensure that only one pressure receptacle is filled at a time.(iii) The filling density for UN pressure receptacles may not exceed the values in accordance with § 173.304b(b) .(2) After each filling, the shipper must verify the leakproofness of the closures and equipment. Each fill opening must be closed by a cap or plug.(c)Damage protection. During transportation, a MEGC must be protected against damage to the pressure receptacles and service equipment resulting from lateral and longitudinal impact and overturning as prescribed in § 178.75 of this subchapter. 71 FR 33884 , June 12, 2006, as amended at 85 FR 85419 , Dec. 28, 2020 As amended at 85 FR 85419 , 12/28/2020