[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR178.75]

[Page 908-919]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 178_SPECIFICATIONS FOR PACKAGINGS--Table of Contents
 
                 Subpart C_Specifications for Cylinders
 
Sec.  178.75  Specifications for MEGCs.

    (a) General. Each MEGC must meet the requirements of this section. 
In a MEGC that meets the definition of a ``container'' within the terms 
of the International Convention for Safe Containers (CSC) must meet the 
requirements of the CSC as amended and 49 CFR parts 450 through 453, and 
must have a CSC approval plate.
    (b) Alternate Arrangements. The technical requirements applicable to 
MEGCs may be varied when the level of safety is determined to be 
equivalent to or exceed the requirements of this subchapter. Such an 
alternate arrangement must be approved in writing by the Associate 
Administrator. MEGCs approved to an Alternate Arrangement must be marked 
as required by paragraph (j) of this section.
    (c) Definitions. The following definitions apply:
    Leakproofness test means a test using gas subjecting the pressure 
receptacles and the service equipment of the MEGC to an effective 
internal pressure of not less than 20% of the test pressure.

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    Manifold means an assembly of piping and valves connecting the 
filling and/or discharge openings of the pressure receptacles.
    Maximum permissible gross mass or MPGM means the heaviest load 
authorized for transport (sum of the tare mass of the MEGC, service 
equipment and pressure receptacle).
    Service equipment means manifold system (measuring instruments, 
piping and safety devices).
    Shut-off valve means a valve that stops the flow of gas.
    Structural equipment means the reinforcing, fastening, protective 
and stabilizing members external to the pressure receptacles.
    (d) General design and construction requirements. (1) The MEGC must 
be capable of being loaded and discharged without the removal of its 
structural equipment. It must possess stabilizing members external to 
the pressure receptacles to provide structural integrity for handling 
and transport. MEGCs must be designed and constructed with supports to 
provide a secure base during transport and with lifting and tie-down 
attachments that are adequate for lifting the MEGC including when loaded 
to its maximum permissible gross mass. The MEGC must be designed to be 
loaded onto a transport vehicle or vessel and equipped with skids, 
mountings or accessories to facilitate mechanical handling.
    (2) MEGCs must be designed, manufactured and equipped to withstand, 
without loss of contents, all normal handling and transportation 
conditions. The design must take into account the effects of dynamic 
loading and fatigue.
    (3) Each pressure receptacle of a MEGC must be of the same design 
type, seamless steel, and constructed and tested according to one of the 
following ISO standards:
    (i) ISO 9809-1: Gas cylinders--Refillable seamless steel gas 
cylinders--Design, construction and testing--Part 1: Quenched and 
tempered steel cylinders with tensile strength less than 1 100 MPa. 
(IBR, see Sec.  171.7 of this subchapter);
    (ii) ISO 9809-2: Gas cylinders--Refillable seamless steel gas 
cylinders--Design, construction and testing--Part 2: Quenched and 
tempered steel cylinders with tensile strength greater than or equal to 
1 100 MPa. (IBR, see Sec.  171.7 of this subchapter);
    (iii) ISO 9809-3: Gas cylinders--Refillable seamless steel gas 
cylinders--Design, construction and testing--Part 3: Normalized steel 
cylinders. (IBR, see Sec.  171.7 of this subchapter); or
    (iv) ISO 11120: Gas cylinders--Refillable seamless steel tubes of 
water capacity between 150 L and 3000 L--Design, construction and 
testing. (IBR, see Sec.  171.7 of this subchapter).
    (4) Pressure receptacles of MEGCs, fittings, and pipework must be 
constructed of a material that is compatible with the hazardous 
materials intended to be transported, as specified in this subchapter.
    (5) Contact between dissimilar metals that could result in damage by 
galvanic action must be prevented by appropriate means.
    (6) The materials of the MEGC, including any devices, gaskets, and 
accessories, must have no adverse effect on the gases intended for 
transport in the MEGC.
    (7) MEGCs must be designed to withstand, without loss of contents, 
at least the internal pressure due to the contents, and the static, 
dynamic and thermal loads during normal conditions of handling and 
transport. The design must take into account the effects of fatigue, 
caused by repeated application of these loads through the expected life 
of the MEGC.
    (8) MEGCs and their fastenings must, under the maximum permissible 
load, be capable of withstanding the following separately applied static 
forces (for calculation purposes, acceleration due to gravity (g) = 9.81 
m/s\2\):
    (i) In the direction of travel: 2g (twice the MPGM multiplied by the 
acceleration due to gravity);
    (ii) Horizontally at right angles to the direction of travel: 1g 
(the MPGM multiplied by the acceleration due to gravity. When the 
direction of travel is not clearly determined, the forces must be equal 
to twice the MPGM);
    (iii) Vertically upwards: 1g (the MPGM multiplied by the 
acceleration due to gravity); and
    (iv) Vertically downwards: 2g (twice the MPGM (total loading 
including the

[[Page 910]]

effect of gravity) multiplied by the acceleration due to gravity.
    (9) Under each of the forces specified in paragraph (d)(8) of this 
section, the stress at the most severely stressed point of the pressure 
receptacles must not exceed the values given in the applicable design 
specifications (e.g., ISO 11120).
    (10) Under each of the forces specified in paragraph (d)(8) of this 
section, the safety factor for the framework and fastenings must be as 
follows:
    (i) For steels having a clearly defined yield point, a safety factor 
of 1.5 in relation to the guaranteed yield strength; or
    (ii) For steels with no clearly defined yield point, a safety factor 
of 1.5 in relation to the guaranteed 0.2 percent proof strength and, for 
austenitic steels, the 1 percent proof strength.
    (11) MEGCs must be capable of being electrically grounded to prevent 
electrostatic discharge when intended for flammable gases.
    (12) The pressure receptacles of a MEGC must be secured in a manner 
to prevent movement that could result in damage to the structure and 
concentration of harmful localized stresses.
    (e) Service equipment. (1) Service equipment must be arranged so 
that it is protected from mechanical damage by external forces during 
handling and transportation. When the connections between the frame and 
the pressure receptacles allow relative movement between the 
subassemblies, the equipment must be fastened to allow movement to 
prevent damage to any working part. The manifolds, discharge fittings 
(pipe sockets, shut-off devices), and shut-off valves must be protected 
from damage by external forces. Manifold piping leading to shut-off 
valves must be sufficiently flexible to protect the valves and the 
piping from shearing, or releasing the pressure receptacle contents. The 
filling and discharge devices, including flanges or threaded plugs, and 
any protective caps must be capable of being secured against unintended 
opening.
    (2) Each pressure receptacle intended for the transport of Division 
2.3 gases must be equipped with an individual shut-off valve. The 
manifold for Division 2.3 liquefied gases 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 an individual shut-off 
valve into assemblies of not more than 3,000 L.
    (3) For MEGC filling and discharge openings:
    (i) Two valves in series must be placed in an accessible position on 
each discharge and filling pipe. One of the valves may be a backflow 
prevention valve. (ii) The filling and discharge devices may be equipped 
to a manifold.
    (iii) For sections of piping which can be closed at both ends and 
where a liquid product can be trapped, a pressure-relief valve must be 
provided to prevent excessive pressure build-up.
    (iv) The main isolation valves on a MEGC must be clearly marked to 
indicate their directions of closure. All shutoff valves must close by a 
clockwise motion of the handwheel.
    (v) Each shut-off valve or other means of closure must be designed 
and constructed to withstand a pressure equal to or greater than 1.5 
times the test pressure of the MEGC.
    (vi) All shut-off valves with screwed spindles must close by a 
clockwise motion of the handwheel. For other shut-off valves, the open 
and closed positions and the direction of closure must be clearly shown.
    (vii) All shut-off valves must be designed and positioned to prevent 
unintentional opening.
    (viii) Ductile metals must be used in the construction of valves or 
accessories.
    (4) The piping must be designed, constructed and installed to avoid 
damage due to expansion and contraction, mechanical shock and vibration. 
Joints in tubing must be brazed or have an equally strong metal union. 
The melting point of brazing materials must be no lower than 525 [deg]C 
(977 [deg]F). The rated pressure of the service equipment and of the 
manifold must be not less than two-thirds of the test pressure of the 
pressure receptacles.
    (f) Pressure relief devices. Each pressure receptacle must be 
equipped with one or more pressure relief devices as

[[Page 911]]

specified in Sec.  173.301(f) of this subchapter. When pressure relief 
devices are installed, each pressure receptacle or group of pressure 
receptacles of a MEGC that can be isolated must be equipped with one or 
more pressure relief devices. Pressure relief devices must be of a type 
that will resist dynamic forces including liquid surge and must be 
designed to prevent the entry of foreign matter, the leakage of gas and 
the development of any dangerous excess pressure.
    (1) The size of the pressure relief devices: CGA S-1.1, 2003 edition 
(IBR, see Sec.  171.7 of this subchapter) must be used to determine the 
relief capacity of individual pressure receptacles.
    (2) Connections to pressure-relief devices: Connections to pressure 
relief devices must be of sufficient size to enable the required 
discharge to pass unrestricted to the pressure relief device. A shut-off 
valve installed between the pressure receptacle and the pressure relief 
device is prohibited, except where duplicate devices are provided for 
maintenance or other reasons, and the shut-off valves serving the 
devices actually in use are locked open, or the shut-off valves are 
interlocked so that at least one of the duplicate devices is always 
operable and capable of meeting the requirements of paragraph (f)(1) of 
this section. No obstruction is permitted in an opening leading to or 
leaving from a vent or pressure-relief device that might restrict or 
cut-off the flow from the pressure receptacle to that device. The 
opening through all piping and fittings must have at least the same flow 
area as the inlet of the pressure relief device to which it is 
connected. The nominal size of the discharge piping must be at least as 
large as that of the pressure relief device.
    (3) Location of pressure-relief devices: For liquefied gases, each 
pressure relief device must, under maximum filling conditions, be in 
communication with the vapor space of the pressure receptacles. The 
devices, when installed, must be arranged to ensure the escaping vapor 
is discharged upwards and unrestrictedly to prevent impingement of 
escaping gas or liquid upon the MEGC, its pressure receptacles or 
personnel. For flammable, pyrophoric and oxidizing gases, the escaping 
gas must be directed away from the pressure receptacle in such a manner 
that it cannot impinge upon the other pressure receptacles. Heat 
resistant protective devices that deflect the flow of gas are 
permissible provided the required pressure relief device capacity is not 
reduced. Arrangements must be made to prevent access to the pressure 
relief devices by unauthorized persons and to protect the devices from 
damage caused by rollover.
    (g) Gauging devices. When a MEGC is intended to be filled by mass, 
it must be equipped with one or more gauging devices. Glass level-gauges 
and gauges made of other fragile material are prohibited.
    (h) MEGC supports, frameworks, lifting and tie-down attachments. (1) 
MEGCs must be designed and constructed with a support structure to 
provide a secure base during transport. MEGCs must be protected against 
damage to the pressure receptacles and service equipment resulting from 
lateral and longitudinal impact and overturning. The forces specified in 
paragraph (d)(8) of this section, and the safety factor specified in 
paragraph (d)(10) of this section must be considered in this aspect of 
the design. Skids, frameworks, cradles or other similar structures are 
acceptable. If the pressure receptacles and service equipment are so 
constructed as to withstand impact and overturning, additional 
protective support structure is not required (see paragraph (h)(4) of 
this section).
    (2) The combined stresses caused by pressure receptacle mountings 
(e.g. cradles, frameworks, etc.) and MEGC lifting and tie-down 
attachments must not cause excessive stress in any pressure receptacle. 
Permanent lifting and tie-down attachments must be equipped to all 
MEGCs. Any welding of mountings or attachments onto the pressure 
receptacles is prohibited.
    (3) The effects of environmental corrosion must be taken into 
account in the design of supports and frameworks.
    (4) When MEGCs are not protected during transport as specified in 
paragraph (h)(1) of this section, the pressure receptacles and service 
equipment must be protected against damage resulting from lateral or 
longitudinal impact or overturning. External fittings

[[Page 912]]

must be protected against release of the pressure receptacles' contents 
upon impact or overturning of the MEGC on its fittings. Particular 
attention must be paid to the protection of the manifold. Examples of 
protection include:
    (i) Protection against lateral impact, which may consist of 
longitudinal bars;
    (ii) Protection against overturning, which may consist of 
reinforcement rings or bars fixed across the frame;
    (iii) Protection against rear impact, which may consist of a bumper 
or frame;
    (iv) Protection of the pressure receptacles and service equipment 
against damage from impact or overturning by use of an ISO frame 
according to the relevant provisions of ISO 1496-3. (IBR, see Sec.  
171.7 of this subchapter).
    (i) Initial inspection and test. The pressure receptacles and items 
of equipment of each MEGC must be inspected and tested before being put 
into service for the first time (initial inspection and test). This 
initial inspection and test of an MEGC must include the following:
    (1) A check of the design characteristics.
    (2) An external examination of the MEGC and its fittings, taking 
into account the hazardous materials to be transported.
    (3) A pressure test performed at the test pressures specified in 
Sec.  173.304b(b)(1) and (2) of this subchapter. The pressure test of 
the manifold may be performed as a hydraulic test or by using another 
liquid or gas. A leakproofness test and a test of the satisfactory 
operation of all service equipment must also be performed before the 
MEGC is placed into service. When the pressure receptacles and their 
fittings have been pressure-tested separately, they must be subjected to 
a leakproof test after assembly.
    (4) An MEGC that meets the definition of ``container'' in the CSC 
(see 49 CFR 450.3(a)(2)) must be subjected to an impact test using a 
prototype representing each design type. The prototype MEGC must be 
shown to be capable of absorbing the forces resulting from an impact not 
less than 4 times (4 g) the MPGM of the fully loaded MEGC, at a duration 
typical of the mechanical shocks experienced in rail transport. A 
listing of acceptable methods for performing the impact test is provided 
in the UN Recommendations (IBR, see Sec.  171.7 of this subchapter).
    (j) Marking. (1) Each MEGC must be equipped with a corrosion 
resistant metal plate permanently attached to the MEGC in a conspicuous 
place readily accessible for inspection. The pressure receptacles must 
be marked according to this section. Affixing the metal plate to a 
pressure receptacle is prohibited. At a minimum, the following 
information must be marked on the plate by stamping or by any other 
equivalent method:


Country of manufacture

                                   UN 
[GRAPHIC] [TIFF OMITTED] TR12JN06.002


Approval Country

Approval Number

Alternate Arrangements (see Sec.  178.75(b))

MEGC Manufacturer's name or mark

MEGC's serial number

Approval agency (Authorized body for the design approval)

Year of manufacture

Test pressure: ------ bar gauge

Design temperature range ------ [deg]C to ------ [deg]C

Number of pressure receptacles ------

Total water capacity ------ liters

Initial pressure test date and identification of the Approval Agency

Date and type of most recent periodic tests

Year ------ Month------ Type ------

(e.g. 2004-05, AE/UE, where ``AE'' represents acoustic emission and 
``UE'' represents ultrasonic examination)


[[Page 913]]


    Stamp of the approval agency who performed or witnessed the most 
recent test
    (2) The following information must be marked on a metal plate firmly 
secured to the MEGC:


Name of the operator

Maximum permissible load mass ------ kg

Working pressure at 15 [deg]C: ------ bar gauge

Maximum permissible gross mass (MPGM) ------ kg

Unladen (tare) mass ------ kg

[71 FR 33892, June 12, 2006]

  Appendix A to Subpart C of Part 178--Illustrations: Cylinder Tensile 
                                 Sample

    The following figures illustrate the recommended locations for test 
specimens taken from welded cylinders:

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[67 FR 51654, Aug. 8, 2002]

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Subparts D-G [Reserved]