49 CFR Ch. V (10–1–14 Edition) § 571.304

§ 571.304 49 CFR Ch. V (10–1–14 Edition)

whichever is less, secured to the vehi- § 571.304 Standard No. 304; Com- cle and distributed so that the weight pressed natural gas fuel container on each axle as measured at the tire- integrity. ground interface is in proportion to its S1. Scope. This standard specifies re- GAWR. Each dummy shall be requirements for the integrity of com- strained only by means that are in- pressed natural gas (CNG), motor vehi- stalled in the vehicle for protection at cle fuel containers. its seating position. S2. Purpose. The purpose of this (c) A schoolbus with a GVWR greater standard is to reduce deaths and inju- than 10,000 pounds, whose fuel system ries occurring from fires that result is filled as specified in S7.1.1 and S7.1.2, from fuel leakage during and after is loaded to its unloaded vehicle motor vehicle crashes. weight, plus 54.4 kg. (120 lb.) of unse- S3. Application. This standard applies cured weight at each designated seat- to each passenger car, multipurpose ing position. passenger vehicle, truck, and bus that S7.1.7 The ambient temperature is uses CNG as a motor fuel and to each not to vary more than 5.6 °C (10 °F) dur- container designed to store CNG as ing the course of the test. motor fuel on-board any motor vehicle. S7.1.8 The pressure drop measure- S4. Definitions. ment specified in S5.2 is to be made Brazing means a group of welding using a location on the high pressure processes wherein coalescence is pro- side of the fuel system in accordance duced by heating to a suitable tem- with the vehicle manufacturer’s rec- perature above 800 °F and by using a ommendation. nonferrous filler metal, having a melt- S7.2 Lateral moving barrier crash test ing point below that to the base met- conditions. The lateral moving barrier als. The filler metal is distributed be- crash test conditions are those speci- tween the closely fitted surfaces of the fied in S8.2 of Standard No. 208, 49 CFR joint by capillary attraction. 571.208. Burst pressure means the highest in- S7.3 Rear moving barrier test condi- ternal pressure reached in a CNG fuel tions. The rear moving barrier test con- container during a burst test at a tem- ditions are those specified in S8.2 of perature of 21 °C (70 °F). Standard No. 208, 49 CFR 571.208, except CNG fuel container means a container for the positioning of the barrier and designed to store CNG as motor fuel the vehicle. The barrier and test vehi- on-board a motor vehicle. cle are positioned so that at impact— Fill pressure means the internal pres- (a) The vehicle is at rest in its nor- sure of a CNG fuel container attained mal attitude; at the time of filling. Fill pressure var- (b) The barrier is traveling at any ies according to the gas temperature in the container which is dependent on speed up to and including 30 mph with the charging parameters and the ambi- its face perpendicular to the longitu- ent conditions. dinal centerline of the vehicle; and Full wrapped means applying the re- (c) A vertical plane through the geo- inforcement of a filament or resin sys- metric center of the barrier impact tem over the entire liner, including the surface and perpendicular to that sur- domes. face coincides with the longitudinal Hoop wrapped means winding of fila- centerline of the vehicle. ment in a substantially circumferen- S7.4 Moving contoured barrier test tial pattern over the cylindrical por- conditions. The moving contoured bar- tion of the liner so that the filament rier crash test conditions are those does not transmit any significant specified in S7.5 of Standard No. 301, 49 stresses in a direction parallel to the CFR 571.301. cylinder longitudinal axis. [59 FR 19659, Apr. 25, 1994; as amended at 60 Hydrostatic pressure means the inter- FR 2543, Jan. 10, 1995; 60 FR 57948, Nov. 24, nal pressure to which a CNG fuel con- 1995] tainer is taken during testing set forth in S5.4.1.

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Liner means the inner gas tight con- when subjected to burst pressure and tainer or gas cylinder to which the tested in accordance with S8.2. Burst overwrap is applied. pressure shall be not less than 2.25 Service pressure means the internal times the service pressure. settled pressure of a CNG fuel con- S7.3 Bonfire test. Each CNG fuel container at a uniform gas temperature of tainer shall be equipped with a pres- 21 °C (70 °F) and full gas content. It is sure relief device. Each CNG fuel con- the pressure for which the container tainer shall completely vent its con- has been constructed under normal tents through a pressure relief device conditions. or shall not burst while retaining its S5 Container and material require- entire contents when tested in accord- ments. ance with S8.3. S5.1 Container designations. Con- S7.4 Labeling. Each CNG fuel container designations are as follows: tainer shall be permanently labeled S5.1.1 Type 1—Non-composite metallic with the information specified in para- container means a metal container. graphs (a) through (h) of this section. S5.1.2 Type 2—Composite metallic Any label affixed to the container in hoop wrapped container means a metal compliance with this section shall re- liner reinforced with resin impregnated main in place and be legible for the continuous filament that is ‘‘hoop wrapped.’’ manufacturer’s recommended service S5.1.3 Type 3—Composite metallic full life of the container. The information wrapped container means a metal liner shall be in English and in letters and 1 reinforced with resin impregnated con- numbers that are at least 6.35 mm ( ⁄4 tinuous filament that is ‘‘full inch) high. wrapped.’’ (a) The statement: ‘‘If there is a S5.1.4 Type 4—Composite non-metallic question about the proper use, installa- full wrapped container means resin im- tion, or maintenance of this container, pregnated continuous filament with a contactllllllllll,’’ inserting non-metallic liner ‘‘full wrapped.’’ the CNG fuel container manufacturer’s S6 General requirements. name, address, and telephone number. S6.1 Each passenger car, multipur- (b) The statement: ‘‘Manufactured in pose passenger vehicle, truck, and bus llllll,’’ inserting the month and that uses CNG as a motor fuel shall be year of manufacture of the CNG fuel equipped with a CNG fuel container container. that meets the requirements of S7 (c) The statement: ‘‘Service pressure through S7.4. llllll kPa, (llllll psig).’’ S6.2 Each CNG fuel container manu- (d) The symbol DOT, constituting a factured on or after March 27, 1995 shall certification by the CNG container meet the requirements of S7 through manufacturer that the container com- S7.4. plies with all requirements of this S7 Test requirements. Each CNG fuel standard. container shall meet the applicable re- (e) The container designation (e.g., quirements of S7 through S7.4. Type 1, 2, 3, 4). S7.1 Pressure cycling test at ambient (f) The statement: ‘‘CNG Only.’’ temperature. Each CNG fuel container shall not leak when tested in accord- (g) The statement: ‘‘This container ance with S8.1. should be visually inspected after a S7.2 Hydrostatic burst test. motor vehicle accident or fire and at S7.2.1 Each Type 1 CNG fuel con- least every 36 months or 36,000 miles, tainer shall not leak when subjected to whichever comes first, for damage and burst pressure and tested in accordance deterioration. with S8.2. Burst pressure shall not be (h) The statement: ‘‘Do Not Use After less than 2.25 times the service pres- llllll’’ inserting the month and sure for non-welded containers and year that mark the end of the manu- shall not be less than 3.5 times the facturer’s recommended service life for service pressure for welded containers. the container. S7.2.2 Each Type 2, Type 3, or Type S8 Test conditions: fuel container in- 4 CNG fuel container shall not leak tegrity.

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S8.1 Pressure cycling test. The re- container so that the center of the fire quirements of S7.1 shall be met under source is 0.825 meters (32.5 inches) from the conditions of S8.1.1 through S8.1.4. the other end of the container, meas- S8.1.1 Hydrostatically pressurize the ured horizontally along a line parallel CNG container to the service pressure, to the longitudinal axis of the con- then to not more than 10 percent of the tainer. service pressure, for 13,000 cycles. (3) Position a CNG fuel container S8.1.2 After being pressurized as that is fitted with pressure relief de- specified in S8.1.1, hydrostatically pres- vices at more than one location along surize the CNG container to 125 percent its length so that the portion of con- of the service pressure, then to not tainer over the center of the fire source more than 10 percent of the service is the portion midway between the two pressure, for 5,000 cycles. pressure relief devices that are sepa- S8.1.3 The cycling rate for S8.1.1 and rated by the greatest distance, meas- S8.1.2 shall be any value up to and in- ured horizontally along a line parallel cluding 10 cycles per minute. to the longitudinal axis of the con- S8.1.4 The cycling is conducted at tainer. ambient temperature. (4) Test a CNG fuel container that is S8.2 Hydrostatic burst test. The re- greater than 1.65 meters (65 inches) in quirements of S7.2 shall be met under length, is protected by thermal insula- the conditions of S8.2.1 through S8.2.2. tion, and does not have pressure relief S8.2.1 Hydrostatically pressurize the devices, twice at 100 percent of service CNG fuel container, as follows: The pressure. In one test, position the cen- pressure is increased up to the min- ter of the container over the center of imum prescribed burst pressure deter- the fire source. In another test, posi- mined in S7.2.1 or S7.2.2, and held con- tion one end of the container so that stant at the minimum burst pressure the fire source is centered 0.825 meters for 10 seconds. (32.5 inches) from one end of the con- S8.2.2 The pressurization rate tainer, measured horizontally along a throughout the test shall be any value line parallel to the longitudinal axis of up to and including 1,379 kPa (200 psi) the container. per second. S8.3.3 Number and placement of S8.3 Bonfire test. The requirements thermocouples. To monitor flame tem- of S7.3 shall be met under the condi- perature, place three thermocouples so tions of S8.3.1 through S8.3.7. that they are suspended 25 mm (one S8.3.1 Fill the CNG fuel container inch) below the bottom of the CNG fuel with compressed natural gas and test it container. Position thermocouples so at: that they are equally spaced over the (a) 100 percent of service pressure; length of the fire source or length of and the container, whichever is shorter. (b) 25 percent of service pressure. S8.3.4 Shielding. S8.3.2 Container positioning. (a) Use shielding to prevent the flame (a) Position the CNG fuel container from directly contacting the CNG fuel in accordance with paragraphs (b) and container valves, fittings, or pressure (c) of S8.3.2. relief devices. (b) Position the CNG fuel container (b) To provide the shielding, use steel so that its longitudinal axis is hori- with 0.6 mm (.025 in) minimum nominal zontal and its bottom is 100 mm (4 thickness. inches) above the fire source. (c) Position the shielding so that it (c)(1) Position a CNG fuel container does not directly contact the CNG fuel that is 1.65 meters (65 inches) in length container valves, fittings, or pressure or less and is fitted with one pressure relief devices. relief device so that the center of the S8.3.5 Fire source. Use a uniform fire container is over the center of the fire source that is 1.65 meters long (65 source. inches). Beginning five minutes after (2) Position a CNG fuel container the fire is ignited, maintain an average that is greater than 1.65 meters (65 flame temperature of not less than 430 inches) in length and is fitted with one degrees Celsius (800 degrees Fahr- pressure relief device at one end of the enheit) as determined by the average of

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the two thermocouples recording the highest temperatures over a 60 second interval:

⎡ ⎤ 1 ⎛ TT+ ⎞ ⎛ TT+ ⎞ ⎢⎜ High 1 High 2⎟ + ⎜ High 1 High 2 ⎟ ⎥ ≥ 430 oC ⎝ ⎠ ⎝ ⎠ 2 ⎣⎢ 22@@ time 30 sec time 60 sec ⎦⎥

If the pressure relief device releases conversion devices into the occupant before the end of the fifth minute after compartment, and electrical shock. ignition, then the minimum tempera- S3. Application. This standard applies ture requirement does not apply. to passenger cars, and to multipurpose S8.3.6 Recording data. Record time, passenger vehicles, trucks and buses temperature, and pressure readings at with a GVWR of 4,536 kg or less, that 30 second intervals, beginning when the use electrical propulsion components fire is ignited and continuing until the with working voltages more than 60 pressure release device releases. volts direct current (VDC) or 30 volts S8.3.7 Duration of exposure to fire alternating current (VAC), and whose source. The CNG fuel container is ex- speed attainable over a distance of 1.6 posed to the fire source for 20 minutes after ignition or until the pressure re- km on a paved level surface is more lease device releases, whichever period than 40 km/h. is shorter. S4. Definitions. S8.3.8 Number of tests per container. A Automatic disconnect means a device single CNG fuel container is not sub- that when triggered, conductively sep- jected to more than one bonfire test. arates a high voltage source from the S8.3.9 Wind velocity. The average electric power train or the rest of the ambient wind velocity at the CNG fuel electric power train. container during the period specified in Electric energy storage device means a S8.3.6 of this standard is not to exceed high voltage source that stores energy 2.24 meters/second (5 mph). for vehicle propulsion. This includes, S8.3.10 The average wind velocity at but is not limited to, a high voltage the container is any velocity up to and battery or battery pack, rechargeable including 2.24 meters/second (5 mph). energy storage device, and capacitor [59 FR 49021, Sept. 26, 1994; 59 FR 66776, Dec. module. 28, 1994; 60 FR 37843, July 24, 1995; 60 FR 57948, Electric energy storage/conversion de- Nov. 24, 1995; 61 FR 19204, May 1, 1996; 61 FR vice means a high voltage source that 47089, Sept. 6, 1996; 63 FR 66765, Dec. 3, 1998; 65 FR 51772, Aug. 25, 2000; 65 FR 64626, Oct. 30, stores or converts energy for vehicle 2000] propulsion. This includes, but is not limited to, a high voltage battery or § 571.305 Standard No. 305; Electric- battery pack, fuel cell stack, recharge- powered vehicles: electrolyte spill- able energy storage device, and capac- age and electrical shock protection. itor module. S1. Scope. This standard specifies re- Electric energy storage/conversion sys- quirements for limitation of electro- tem means an assembly of electrical lyte spillage, retention of electric en- components that stores or converts ergy storage/conversion devices, and electrical energy for vehicle propul- protection from harmful electric shock sion. This includes, but is not limited during and after a crash. to, high voltage batteries or battery S2. Purpose. The purpose of this packs, fuel cell stacks, rechargeable standard is to reduce deaths and inju- energy storage systems, capacitor mod- ries during and after a crash that oc- curs because of electrolyte spillage ules, inverters, interconnects, and from electric energy storage devices, venting systems. intrusion of electric energy storage/

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