49 CFR 178.71 - Specifications for UN pressure receptacles.

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§ 178.71 Specifications for UN pressure receptacles.
(a) General. Each UN pressure receptacle must meet the requirements of this section. Requirements for approval, qualification, maintenance, and testing are contained in § 178.70, and subpart C of part 180 of this subchapter.
(b) Definitions. The following definitions apply for the purposes of design and construction of UN pressure receptacles under this subpart:
Alternative arrangement means an approval granted by the Associate Administrator for a MEGC that has been designed, constructed or tested to the technical requirements or testing methods other than those specified for UN pressure receptacles in part 178 or part 180 of this subchapter.
Bundle of cylinders. See§ 171.8 of this subchapter.
Design type means a pressure receptacle design as specified by a particular pressure receptacle standard.
Design type approval means an overall approval of the manufacturer's quality system and design type of each pressure receptacle to be produced within the manufacturer's facility.
UN tube. See§ 171.8 of this subchapter.
(c) Following the final heat treatment, all cylinders, except those selected for batch testing must be subjected to a proof pressure or a hydraulic volumetric expansion test.
(d) Service equipment.
(1) Except for pressure relief devices, UN pressure receptacle equipment, including valves, piping, fittings, and other equipment subjected to pressure must be designed and constructed to withstand at least 1.5 times the test pressure of the pressure receptacle.
(2) Service equipment must be configured or designed to prevent damage that could result in the release of the pressure receptacle contents during normal conditions of handling and transport. 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 valves and any protective caps must be secured against unintended opening. The valves must conform to ISO 10297 (IBR, see§ 171.7 of this subchapter) and be protected as specified in § 173.301b(f) of this subchapter.
(3) UN pressure receptacles that cannot be handled manually or rolled, must be equipped with devices (e.g., skids, rings, straps) ensuring that they can be safely handled by mechanical means and so arranged as not to impair the strength of, nor cause undue stresses, in the pressure receptacle.
(4) Pressure receptacles filled by volume must be equipped with a level indicator.
(e) Bundles of cylinders. UN pressure receptacles assembled in bundles must be structurally supported and held together as a unit and secured in a manner that prevents movement in relation to the structural assembly and movement that would result in the concentration of harmful local stresses. The frame design must ensure stability under normal operating conditions.
(1) The frame must securely retain all the components of the bundle and must protect them from damage during conditions normally incident to transportation. The method of cylinder restraint must prevent any vertical or horizontal movement or rotation of the cylinder that could cause undue strain on the manifold. The total assembly must be able to withstand rough handling, including being dropped or overturned.
(2) The frame must include features designed for the handling and transportation of the bundle. The lifting rings must be designed to withstand a design load of 2 times the maximum gross weight. Bundles with more than one lifting ring must be designed such that a minimum sling angle of 45 degrees to the horizontal can be achieved during lifting using the lifting rings. If four lifting rings are used, their design must be strong enough to allow the bundle to be lifted by two rings. Where two or four lifting rings are used, diametrically opposite lifting rings must be aligned with each other to allow for correct lifting using shackle pins. If the bundle is filled with forklift pockets, it must contain two forklift pockets on each side from which it is to be lifted. The forklift pockets must be positioned symmetrically consistent with the bundle center of gravity.
(3) The frame structural members must be designed for a vertical load of 2 times the maximum gross weight of the bundle. Design stress levels may not exceed 0.9 times the yield strength of the material.
(4) The frame must not contain any protrusions from the exterior frame structure that could cause a hazardous condition.
(5) The frame design must prevent collection of water or other debris that would increase the tare weight of bundles filled by weight.
(6) The floor of the bundle frame must not buckle during normal operating conditions and must allow for the drainage of water and debris from around the base of the cylinders.
(7) If the frame design includes movable doors or covers, they must be capable of being secured with latches or other means that will not become dislodged by operational impact loads. Valves that need to be operated in normal service or in an emergency must be accessible.
(8) For bundles of cylinders, pressure receptacle marking requirements only apply to the individual cylinders of a bundle and not to any assembly structure.
(f) Design and construction requirements for UN refillable welded cylinders. In addition to the general requirements of this section, UN refillable welded cylinders must conform to the following ISO standards, as applicable:
(1) ISO 4706: Gas cylinders—Refillable welded steel cylinders—Test pressure 60 bar and below (IBR, see§ 171.7 of this subchapter).
(2) ISO 18172-1: Gas cylinders—Refillable welded stainless steel cylinders—Part 1: Test pressure 6 MPa and below (IBR, see§ 171.7 of this subchapter).
(3) ISO 20703: Gas cylinders—Refillable welded aluminum-alloy cylinders—Design, construction and testing (IBR, see§ 171.7 of this subchapter).
(g) Design and construction requirements for UN refillable seamless steel cylinders. In addition to the general requirements of this section, UN refillable seamless steel cylinders must conform to the following ISO standards, as applicable:
(1) 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§ 171.7 of this subchapter).
(2) 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§ 171.7 of this subchapter).
(3) ISO 9809-3: Gas cylinders—Refillable seamless steel gas cylinders—Design, construction and testing—Part 3: Normalized steel cylinders. (IBR, see§ 171.7 of this subchapter).
(h) Design and construction requirements for UN refillable seamless aluminum alloy cylinders. In addition to the general requirements of this section, UN refillable seamless aluminum cylinders must conform to ISO 7866: Gas cylinders—Refillable seamless aluminum alloy gas cylinders—Design, construction and testing. (IBR, see§ 171.7 of this subchapter). The use of Aluminum alloy 6351-T6 or equivalent is prohibited.
(i) Design and construction requirements for UN non-refillable metal cylinders. In addition to the general requirements of this section, UN non-refillable metal cylinders must conform to ISO 11118: Gas cylinders—Non-refillable metallic gas cylinders—Specification and test methods. (IBR, see§ 171.7 of this subchapter.)
(j) Design and construction requirements for UN refillable seamless steel tubes. In addition to the general requirements of this section, UN refillable seamless steel tubes must conform to ISO 11120: Gas cylinders—Refillable seamless steel tubes of water capacity between 150 L and 3000 L—Design, construction and testing. (IBR, see§ 171.7 of this subchapter).
(k) Design and construction requirements for UN acetylene cylinders. In addition to the general requirements of this section, UN acetylene cylinders must conform to the following ISO standards, as applicable:
(1) For the cylinder shell:
(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.
(ii) ISO 9809-3: Gas cylinders—Refillable seamless steel gas cylinders—Design, construction and testing—Part 3: Normalized steel cylinders.
(2) The porous mass in an acetylene cylinder must conform to ISO 3807-2: Cylinders for acetylene—Basic requirements—Part 2: Cylinders with fusible plugs. (IBR, see§ 171.7 of this subchapter).
(l) Design and construction requirements for UN composite cylinders.
(1) In addition to the general requirements of this section, UN composite cylinders must be designed for unlimited service life and conform to the following ISO standards, as applicable:
(i) ISO 11119-1: Gas cylinders of composite construction—Specification and test methods—Part 1: Hoop-wrapped composite gas cylinders. (IBR, see§ 171.7 of this subchapter).
(ii) ISO 11119-2: Gas cylinders of composite construction—Specification and test methods—Part 2: Fully-wrapped fibre reinforced composite gas cylinders with load-sharing metal liners. (IBR, see§ 171.7 of this subchapter).
(iii) ISO 11119-3: Gas cylinders of composite construction—Specification and test methods—Part 3: Fully wrapped fibre reinforced composite gas cylinders with non-load sharing metallic or non-metallic liners. (IBR, see§ 171.7 of this subchapter).
(2) ISO 11119-2 and ISO 11119-3 gas cylinders of composite construction manufactured in accordance with the requirements for underwater use must bear the “UW” mark.
(m) Design and construction requirements for UN metal hydride storage systems. In addition to the general requirements of this section, metal hydride storage systems must conform to the following ISO standards, as applicable: ISO 16111: Transportable gas storage devices—Hydrogen absorbed in reversible metal hydride (IBR, see§ 171.7 of this subchapter).
(n) Material compatibility. In addition to the material requirements specified in the UN pressure receptacle design and construction ISO standards, and any restrictions specified in part 173 for the gases to be transported, the requirements of the following standards must be applied with respect to material compatibility:
(1) ISO 11114-1: Transportable gas cylinders—Compatibility of cylinder and valve materials with gas contents—Part 1: Metallic materials. (IBR, see§ 171.7 of this subchapter).
(2) ISO 11114-2: Transportable gas cylinders—Compatibility of cylinder and valve materials with gas contents—Part 2: Non-metallic materials. (IBR, see§ 171.7 of this subchapter).
(o) Protection of closures. Closures and their protection must conform to the requirements in § 173.301(f) of this subchapter.
(p) Marking of UN refillable pressure receptacles. UN refillable pressure receptacles must be marked clearly and legibly. The required markings must be permanently affixed by stamping, engraving, or other equivalent method, on the shoulder, top end or neck of the pressure receptacle or on a permanently affixed component of the pressure receptacle, such as a welded collar. Except for the “UN” mark, the minimum size of the marks must be 5 mm for pressure receptacles with a diameter greater than or equal to 140 mm, and 2.5 mm for pressure receptacles with a diameter less than 140 mm. The minimum size of the “UN” mark must be 5 mm for pressure receptacles with a diameter less than 140 mm, and 10 mm for pressure receptacles with a diameter of greater than or equal to 140 mm. The depth of the markings must not create harmful stress concentrations. A refillable pressure receptacle conforming to the UN standard must be marked as follows:
(1) The UN packaging symbol.
(2) The ISO standard, for example ISO 9809-1, used for design, construction and testing. Acetylene cylinders must be marked to indicate the porous mass and the steel shell, for example: “ISO 3807-2/ISO 9809-1.”
(3) The mark of the country where the approval is granted. The letters “USA” must be marked on UN pressure receptacles approved by the United States. The manufacturer must obtain an approval number from the Associate Administrator. The manufacturer approval number must follow the country of approval mark, separated by a slash (for example, USA/MXXXX). Pressure receptacles approved by more than one national authority may contain the mark of each country of approval, separated by a comma.
(4) The identity mark or stamp of the IIA.
(5) The date of the initial inspection, the year (four digits) followed by the month (two digits) separated by a slash, for example “2006/04”.
(6) The test pressure in bar, preceded by the letters “PH” and followed by the letters “BAR”.
(7) The rated charging pressure of the metal hydride storage system in bar, preceded by the letters “RCP” and followed by the letters “BAR.”
(8) The empty or tare weight. Except for acetylene cylinders, empty weight is the mass of the pressure receptacle in kilograms, including all integral parts (e.g., collar, neck ring, foot ring, etc.), followed by the letters “KG”. The empty weight does not include the mass of the valve, valve cap or valve guard or any coating. The empty weight must be expressed to three significant figures rounded up to the last digit. For cylinders of less than 1 kg, the empty weight must be expressed to two significant figures rounded down to the last digit. For acetylene cylinders, the tare weight must be marked on the cylinders in kilograms. The tare weight is the sum of the empty weight, mass of the valve, any coating and all permanently attached parts (e.g., fittings and accessories) that are not removed during filling. The tare weight must be expressed to two significant figures rounded down to the last digit. The tare weight does not include the cylinder cap or any outlet cap or plug not permanently attached to the cylinder.
(9) The minimum wall thickness of the pressure receptacle in millimeters followed by the letters “MM”. This mark is not required for pressure receptacles with a water capacity less than or equal to 1.0 L or for composite cylinders.
(10) For pressure receptacles intended for the transport of compressed gases and UN 1001 acetylene, dissolved, the working pressure in bar, proceeded by the letters “PW”.
(11) For liquefied gases, the water capacity in liters expressed to three significant digits rounded down to the last digit, followed by the letter “L”. If the value of the minimum or nominal water capacity is an integer, the digits after the decimal point may be omitted.
(12) Identification of the cylinder thread type (e.g., 25E).
(13) The country of manufacture. The letters “USA” must be marked on cylinders manufactured in the United States.
(14) The serial number assigned by the manufacturer.
(15) For steel pressure receptacles, the letter “H” showing compatibility of the steel, as specified in 1SO 11114-1.
(16) Identification of aluminum alloy, if applicable.
(17) Stamp for nondestructive testing, if applicable.
(18) Stamp for underwater use of composite cylinders, if applicable.
(19) For metal hydride storage systems having a limited life, the date of expiration indicated by the word “FINAL,” followed by the year (four digits), the month (two digits) and separated by a slash.
(q) Marking sequence. The marking required by paragraph (p) of this section must be placed in three groups as shown in the example below:
(1) The top grouping contains manufacturing marks and must appear consecutively in the sequence given in paragraphs (p)(13) through (19) of this section.
(2) The middle grouping contains operational marks described in paragraphs (p)(6) through (11) of this section.
(3) The bottom grouping contains certification marks and must appear consecutively in the sequence given in paragraphs (p)(1) through (5) of this section.
(r) Other markings. Other markings are allowed in areas other than the side wall, provided they are made in low stress areas and are not of a size and depth that will create harmful stress concentrations. Such marks must not conflict with required marks.
(s) Marking of UN non-refillable pressure receptacles. Unless otherwise specified in this paragraph, each UN non-refillable pressure receptacle must be clearly and legibly marked as prescribed in paragraph (p) of this section. In addition, permanent stenciling is authorized. Except when stenciled, the marks must be on the shoulder, top end or neck of the pressure receptacle or on a permanently affixed component of the pressure receptacle (e.g., a welded collar).
(1) The marking requirements and sequence listed in paragraphs (p)(1) through (19) of this section are required, except the markings in paragraphs (p)(8), (9), (12) and (18) are not applicable. The required serial number marking in paragraph (p)(14) may be replaced by the batch number.
(2) Each receptacle must be marked with the words “DO NOT REFILL” in letters of at least 5 mm in height.
(3) A non-refillable pressure receptacle, because of its size, may substitute the marking required by this paragraph with a label. Reduction in marking size is authorized only as prescribed in ISO 7225, Gas cylinders—Precautionary labels. (IBR, see§ 171.7 of this subchapter).
(4) Each non-refillable pressure receptacle must also be legibly marked by stenciling the following statement: “Federal law forbids transportation if refilled-penalty up to $500,000 fine and 5 years in imprisonment (49 U.S.C. 5124).”
(5) No person may mark a non-refillable pressure receptacle as meeting the requirements of this section unless it was manufactured in conformance with this section.
[76 FR 3385, Jan. 19, 2011, as amended at 76 FR 43532, July 20, 2011]

Title 49 published on 2013-10-01

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  • 2014-03-18; vol. 79 # 52 - Tuesday, March 18, 2014
    1. 79 FR 15033 - Hazardous Materials: Adoption of Certain Special Permits and Competent Authorities Into Regulations
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      DEPARTMENT OF TRANSPORTATION, Pipeline and Hazardous Materials Safety Administration
      Final rule.
      This regulation is effective April 17, 2014. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of April 17, 2014.
      49 CFR Parts 107, 171, 172, 173, 175 and 178

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United States Code

Title 49 published on 2013-10-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 49 CFR 178 after this date.

  • 2014-03-18; vol. 79 # 52 - Tuesday, March 18, 2014
    1. 79 FR 15033 - Hazardous Materials: Adoption of Certain Special Permits and Competent Authorities Into Regulations
      GPO FDSys XML | Text
      DEPARTMENT OF TRANSPORTATION, Pipeline and Hazardous Materials Safety Administration
      Final rule.
      This regulation is effective April 17, 2014. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of April 17, 2014.
      49 CFR Parts 107, 171, 172, 173, 175 and 178