Compressed Gases in Cargo Tanks and Portable Tanks

Pipeline and Haz. Matls. Safety Admin., DOT § 173.315

27.6 Bar (400 psi) on DOT 105A600W cordance with this section, § 173.32, tanks. Each regulating valve and pres- § 173.33 and subpart E or subpart G of sure relief device must have its final part 180 of this subchapter, as applica- discharge piped to the outside of the ble. For cryogenic liquid in cargo protective housing. tanks, see § 173.318. For marking re- [Amdt. 173–224, 55 FR 52665, Dec. 21, 1990] quirements for portable tanks and cargo tanks, see § 172.326 and § 172.328 of EDITORIAL NOTE: For FEDERAL REGISTER ci- this subchapter, as applicable. tations affecting § 173.314, see the List of CFR Sections Affected, which appears in the (1) UN portable tanks: UN portable Finding Aids section of the printed volume tanks must be loaded and offered for and at www.fdsys.gov. transportation in accordance with portable tank provision T50 in § 172.102 § 173.315 Compressed gases in cargo of this subchapter. tanks and portable tanks. (2) Cargo tanks and DOT specification (a) Liquefied compressed gases that portable tanks: Cargo tanks and DOT are transported in UN portable tanks, specification portable tanks must be DOT specification portable tanks, or loaded and offered for transportation in cargo tanks must be prepared in ac- accordance with the following table:

Maximum permitted filling density Specification container required Kind of gas Percent by volume Percent by weight (see par. (f) of this Type (see Note 2) Minimum design (see Note 1) section) pressure (psig)

Ammonia, anhydrous or Ammonia solu- 56 ...... 82, See Note 5 ...... DOT-51, MC–330, 265; See Note 17. tions with greater than 50 percent MC–331; See ammonia (see Notes 14 and 17). Notes 12, 17 and 27. Ammonia solutions with more than 35 See par. (c) of this See Note 7 ...... DOT-51, MC–330, 100; See par. (c) of percent but not more than 50 percent section. MC–331; see this section. ammonia. Note 12. Bromotrifluoromethane (R–13B1 or H– 133 ...... See Note 7 ...... DOT-51, MC–330, 365. 1301); (See Note 9). MC–331. Butadiene, stabilized ...... See par. (b) of this See par. (b) of this DOT-51, MC–330, 100. section. section. MC–331. Carbon dioxide, refrigerated liquid ...... See par. (c)(1) of 95 ...... do ...... 200; see Note 3. this section. Chlorine ...... 125 ...... See Note 7 ...... DOT-51, MC–330, 225; See Notes 4 MC–331. and 8. Chlorodifluoroethane (R–142b) (1- 100 ...... See Note 7 ...... DOT-51, MC–330, 100. Chloro 1,1-difluoroethane); (See Note MC–331. 9). Chlorodifluoromethane (R–22); (See 105 ...... See Note 7 ...... DOT-51, MC–330, 250. Note 9). MC–331. Chloropentafluoroethane (R–115); (See See par. (c) of this See Note 7 ...... DOT-51, MC–330, See par. (c) of this Note 9). section. MC–331. section. Chlorotrifluoromethane (R–13); (See See par. (c) of this See Note 7 ...... DOT-51, MC–330, See par. (c) of this Note 9). section. MC–331. section. Dichlorodifluoromethane (R–12); (See 119 ...... See Note 7 ...... DOT-51, MC–330, 150. Note 9). MC–331. Difluoroethane (R–152a); (See Note 9) 79 ...... See Note 7 ...... DOT-51, MC–330, 150. MC–331. Dimethyl ether (see Note 16) ...... 59 ...... do ...... do ...... 200. Dimethylamine, anhydrous ...... 59 ...... See Note 7 ...... DOT-51, MC–330, 150. MC–331. Division 2.1, materials not specifically See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 18. provided for in this table. section. MC–331. Division 2.2, materials not specifically See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 19. provided for in this table. section. MC–331. Division 2.3, Hazard Zone A, materials See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 20. not specifically provided for in this section. MC–331; See table. Note 23. Division 2.3, Hazard Zone B, materials See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 20. not specifically provided for in this section. MC–331; See table. Note 23. Division 2.3, Hazard Zone C, materials See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 21. not specifically provided for in this section. MC–331; See table. Note 24.

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Division 2.3, Hazard Zone D, materials See par. (c) of this See Note 7 ...... DOT-51, MC–330, See Note 22. not specifically provided for in this section. MC–331; See table. Note 25. Ethane, refrigerated liquid ...... See par. (c) of this MC–331, MC–338 100; see Note 11. section. Ethane-propane mixture, refrigerated ...... See par. (c) of this MC–331, MC–338 275; see Note 11. liquid. section. Hexafluoropropylene ...... 110 ...... See Note 7 ...... DOT-51, MC–330, 250. MC–331. Hydrogen chloride, refrigerated liquid .... 103.0 ...... See Note 7 ...... MC–331, MC–338 100; see Note 11. 91.6 ...... do ...... do ...... 300; see Note 11. 86.7 ...... do ...... do ...... 450; see Note 11. Liquefied petroleum gas (see Note 15) See par. (b) of this See par. (b) of this DOT-51, MC–330, See par. (c) of this section. section. MC–331; See section. Note 26. Methylacetylene-propadiene, stabilized 53 ...... 90 ...... DOT 51, MC 330, 200. (see Note 13). MC 331. Methylamine, anhydrous ...... 60 ...... See Note 7 ...... DOT-51, MC–330, MC–331.. Methyl chloride ...... 84 ...... 88.5 ...... do ...... 150. Methyl chloride (optional portable tank ...... do ...... See Note 6 ...... DOT-51 ...... 225. 2,000 pounds water capacity, fusible plug). Methyl mercaptan ...... 80 ...... 90 ...... DOT-51, MC–330, 100. MC–331; See Note 23. Nitrous oxide, refrigerated liquid ...... See par. (c)(1) of 95 ...... DOT-51, MC–330, 200; See Note 3. this section. MC–331. Refrigerant gas, n.o.s. or Dispersant See par. (c) of this See Note 7 ...... DOT-51, MC–330, See par. (c) of this gas, n.o.s. (See Note 9). section. MC–331. section. Sulfur dioxide (tanks not over 1,200 gal- 125 ...... 87.5 ...... DOT-51, MC–330, 150; See Note 4. lons water capacity). MC–331; See Note 24. Sulfur dioxide (tanks over 1,200 gallons 125 ...... 87.5 ...... DOT-51, MC–330, 125; See Note 4. water capacity). MC–331; See Note 24. Sulfur dioxide (optional portable tank 125 ...... See Note 6 ...... DOT-51; See Note 225. 1,000–2,000 pounds water capacity, 24. fusible plug). Trimethylamine, anhydrous ...... 57 ...... See Note 7 ...... DOT-51, MC–330, 150. MC–331. Vinyl chloride ...... 84 (see Note 13) ... See Note 7 ...... MC–330, MC–331 150. Vinyl fluoride, stabilized ...... 66 ...... do ...... do ...... 250; see Note 11. Vinyl methyl ether ...... 68 ...... See Notes 7 and ...... do ...... 100. 13.

NOTE 1: Maximum filling density for liquefied gases is hereby defined as the percent ratio of the weight of gas in the tank to the weight of water that the tank will hold. For determining the water capacity of the tank in pounds, the weight of a gallon (231 cubic inches) of water at 60 °F. in air shall be 8.32828 pounds. NOTE 2: See § 173.32 for authority to use other portable tanks and for manifolding cargo tanks, see paragraph (q) of this section. Specifications MC 330 cargo tanks may be painted as specified for MC 331 cargo tanks. NOTE 3: If cargo tanks and portable tank containers for carbon dioxide, refrigerated liquid, and nitrous oxide, refrigerated liquid, are designed to conform to the requirements in Section VIII of the ASME Code for low temperature operation (IBR, see § 171.7 of this subchapter), the design pressure may be reduced to 100 psig or the controlled pressure, whichever is greater. NOTE 4: Material must be steel. Packagings must have a corrosion allowance of 20 percent or 0.10 inch, whichever is less, added to the metal thickness. The minimum wall thickness for chlorine packagings is 0.300 inch for stainless steel or 0.625 inch for carbon steel, including corrosion allowance. NOTE 5: Unlagged cargo tanks and portable tank containers for liquid anhydrous ammonia may be filled to 87.5 percent by volume provided the temperature of the anhydrous ammonia being loaded into such tanks is determined to be not lower than 30 °F. or provided the filling of such tanks is stopped at the first indication of frost or ice formation on the outside surface of the tank and is not resumed until such frost or ice has disappeared. NOTE 6: Tanks equipped with fusible plugs must be filled by weight. NOTE 7: Tanks must be filled by weight. NOTE 8: Chlorine packagings may be shipped only if the contents are to be unloaded at one unloading point. NOTE 9: This gas may be transported in authorized cargo tanks and portable tanks marked ‘‘DISPERSANT GAS,’’ or ‘‘REFRIGERANT GAS.’’ NOTE 10: [Reserved] NOTE 11: MC–330, MC–331 and MC–338 cargo tanks must be insulated. Cargo tanks must meet all the following requirements. Each tank must have a design service temperature of minus 100 °F., or no warmer than the boiling point at one atmos- phere of the hazardous material to be shipped therein, whichever is colder, and must conform to the low-temperature requirements in Section VIII of the ASME Code. When the normal travel time is 24 hours or less, the tank’s holding time as loaded must be at least twice the normal travel time. When the normal travel time exceeds 24 hours, the tank’s holding time as loaded must be at least 24 hours greater than the normal travel time. The holding time is the elapsed time from loading until venting oc- curs under equilibrium conditions. The cargo tank must have an outer jacket made of steel when the cargo tank is used to transport a flammable gas.

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NOTE 12: No aluminum, copper, silver, zinc or an alloy of any of these metals shall be used in packaging construction where it comes into contact with the lading. NOTE 13: All parts of valves and safety devices in contact with contents of tank must be of a metal or other material suitably treated if necessary, which will not cause formation of any acetylides. NOTE 14: Specifications MC 330 and MC 331 cargo tanks constructed of other than quenched and tempered steel ‘‘(NQT)’’ are authorized for all grades of anhydrous ammonia. Specifications MC 330 and MC 331 cargo tanks constructed of quenched and tempered steel ‘‘(QT)’’ (see marking requirements of § 172.328(c) of this subchapter) are authorized for anhydrous ammonia having a minimum water content of 0.2 percent by weight. Any tank being placed in anhydrous ammonia service or a tank which has been in other service or has been opened for inspection, test, or repair, must be cleaned of the previous product and must be purged of air before loading. See § 172.203(h) of this subchapter for special shipping paper requirements. NOTE 15: Specifications MC 330 and MC 331 cargo tanks constructed of other than quenched and tempered steel (NQT) are authorized for all grades of liquefied petroleum gases. Only grades of liquefied petroleum gases determined to be ‘‘noncorrosive’’ are authorized in Specification MC 330 and MC 331 cargo tanks constructed of quenched and tempered steel (QT). ‘‘Noncorro- sive’’ means the corrosiveness of the gas does not exceed the limitations for classification 1 of the ASTM Copper Strip Classi- fications when tested in accordance with ASTM D 1838, ‘‘Copper Strip Corrosion by Liquefied Petroleum (LP) Gases’’ (IBR, see § 171.7 of this subchapter). (For (QT) and (NQT) marking requirements, see § 172.328(c) of this subchapter. For special shipping paper requirements, see § 172.203(h) of this subchapter.) NOTE 16: Openings, inlets, and outlets on MC 330 and MC 331 cargo tanks must conform to § 178.337–8(a) of this subchapter. MC 330 and MC 331 cargo tanks must be equipped with emergency discharge control equipment as specified in § 178.337–11(a) of this subchapter. NOTE 17: A Specification MC-330 or MC-331 cargo tank or a nonspecification cargo tank meeting, and marked in conformance with, the edition of the ASME Code in effect when it was fabricated, may be used for the transportation of anhydrous ammonia if it: (1) Has a minimum design pressure not lower than 250 psig; (2) Was manufactured in conformance with the ASME Code prior to January 1, 1981, according to its ASME name plate and manufacturer’s data report; (3) Is painted white or aluminum; (4) Complies with Note 12 of this paragraph; (5) Has been inspected and tested in accordance with subpart E of part 180 of this subchapter as specified for MC 331 cargo tanks. (6) Was used to transport anhydrous ammonia prior to January 1, 1981; (7) Is operated exclusively in intrastate commerce (including its operation by a motor carrier otherwise engaged in interstate commerce) in a state where its operation was permitted by the laws of that State (not including the incorporation of this subchapter) prior to January 1, 1981; and (8) Is operated in conformance with all other requirements of this subchapter. NOTE 18: The minimum packaging design pressure must not be less than the vapor pressure at the reference temperature of the lading plus one percent or 173.4 kPa (25 psig), whichever is less. NOTE 19: The minimum packaging design pressure must not be less than the vapor pressure at the reference temperature of the lading. NOTE 20: The minimum packaging design pressure must not be less than 1.5 times the vapor pressure of the lading at 46 °C (115 °F). NOTE 21: The minimum packaging design pressure must not be less than 1.3 times the vapor pressure of the lading at 46 °C (115 °F). NOTE 22: The minimum packaging design pressure must not be less than 1.1 times the vapor pressure of the lading at 46 °C (115 °F). NOTE 23: Packagings must be made of stainless steel except that steel other than stainless steel may be used in accordance with the provisions of § 173.24b(b) of this part. Thickness of stainless steel for shell and heads must be the greater of 7.62 mm (0.300 inch) or the thickness required for the packaging at its minimum design pressure. NOTE 24: Packagings must be made of stainless steel except that steel other than stainless steel may be used in accordance with the provisions of § 173.24b(b) of this part. Thickness of stainless steel for shell and heads must be the greater of 6.35 mm (0.250 inch) or the thickness required for the packaging at its minimum design pressure. For sulphur dioxide, this Note does not apply until October 1, 1994. NOTE 25: Packagings must be made of stainless steel except that steel other than stainless steel may be used in accordance with the provisions of § 173.24b(b) of this part. Thickness for shell and heads must be as calculated for the packaging at its minimum design pressure. NOTE 26: Non-specification cargo tanks may be used for the transportation of liquefied petroleum gas, subject to the conditions prescribed in paragraph (k) of this section. NOTE 27: Non-specification cargo tanks may be used for transportation of Ammonia, anhydrous and ammonia solutions with greater than 50% ammonia, subject to the conditions prescribed in paragraph (m) of this section.

(b) Maximum permitted filling den- Maximum permitted fill- sities for cargo and portable tank con- ing density in percent of the water-weight ca- tainers for transportation of butadiene, Maximum specific gravity of the pacity of the tanks (per- stabilized, and liquefied petroleum gas liquid material at 60 °F. cent) See Note 1 are as follows: 1200 gal- Over 1200 lons or gallons Maximum permitted fill- less ing density in percent of the water-weight ca- 0.520 to 0.527 ...... 44 47 Maximum specific gravity of the pacity of the tanks (per- 0.528 to 0.536 ...... 45 48 liquid material at 60 °F. cent) See Note 1 0.537 to 0.544 ...... 46 49 1200 gal- 0.545 to 0.552 ...... 47 50 lons or Over 1200 0.553 to 0.560 ...... 48 51 less gallons 0.561 to 0.568 ...... 49 52 0.569 to 0.576 ...... 50 53 0.473 to 0.480 ...... 38 41 0.577 to 0.584 ...... 51 54 0.481 to 0.488 ...... 39 42 0.585 to 0.592 ...... 52 55 0.489 to 0.495 ...... 40 43 0.593 to 0.600 ...... 53 56 0.496 to 0.503 ...... 41 44 0.601 to 0.608 ...... 54 57 0.504 to 0.510 ...... 42 45 0.609 to 0.617 ...... 55 58 0.511 to 0.519 ...... 43 46 0.618 to 0.626 ...... 56 59

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Maximum permitted fill- level exceeding 95 percent of the volu- ing density in percent metric capacity of the tank. of the water-weight ca- (2) A tank containing ethane, refrig- Maximum specific gravity of the pacity of the tanks (per- liquid material at 60 °F. cent) See Note 1 erated liquid; ethane-propane mixture, refrigerated liquid; or hydrogen chloride, re- 1200 gal- Over 1200 lons or frigerated liquid. Such tank must be less gallons filled to allow at least two percent out- 0.627 and over ...... 57 60 age below the inlet of the pressure re-

NOTE 1: Filling is permitted by volume provided the same lief valve or pressure control valve filling density is used as permitted by weight, except when under conditions of incipient opening, using fixed length dip tube or other fixed maximum liquid level indicators (paragraph (f) of this section), in which case the with the tank in a level attitude. maximum permitted filling density shall not exceed 97 percent (d) If the loading of cargo tanks and of the maximum permitted filling density by weight contained in the table. portable tank containers with liquefied gases is to be determined by weight, (1) Odorization. All liquefied petro- the gross weight shall be checked after leum gas shall be effectively odorized the filling line is disconnected in each as required in Note 2 of this paragraph instance. The gross weight shall be cal- to indicate positively, by a distinctive culated from the tank capacity and odor, the presence of gas down to a tare weight set forth on the metal concentration in air of not over one- plate required by the specification, and fifth the lower limit of combustibility the maximum filling density permitted provided, however, that odorization is for the material being loaded into the not required if harmful in the use or tank as set forth in the table, para- further processing of the liquefied pe- graph (a) of this section. troleum gas, or if odorization will serve (e) If the loading of cargo tanks and no useful purpose as a warning agent in portable tank containers with liquefied such use or further processing. gases is to be determined by adjustable liquid level device, each tank and each NOTE 1: The lower limits of combustibility of the more commonly used liquefied petro- compartment thereof shall have a ther- leum gases are: Propane, 2.15 percent; bu- mometer well, so that the internal liq- tane, 1.55 percent. These figures represent uid temperature can easily be deter- volumetric percentages of gas-air mixtures mined, and the amount of liquid in the in each case. tank shall be corrected to a 60 °F. NOTE 2: The use of 1.0 pound of ethyl basis. Liquid levels shall not exceed a mercaptan, 1.0 pound of thiophane, or 1.4 level corresponding to the maximum pounds of amyl mercaptan per 10,000 gallons filling density permitted for the mate- of liquefied petroleum gas shall be consid- rial being loaded into the tank as set ered sufficient to meet the requirements of forth in the table in paragraph (a) of § 173.315(b)(1). This note does not exclude the use of any other odorant in sufficient quan- this section. tity to meet the requirements of (f) When the loading of cargo tanks § 173.315(b)(1). and portable tank containers with liquefied gases is determined only by (c) Except as otherwise provided, the fixed length dip tube or other fixed loading of a liquefied gas into a cargo maximum liquid level indicator, the tank or portable tank shall be deter- device shall be arranged to function at mined by weight or by a suitable liquid a level not to exceed the maximum per- level gauging device. The vapor pres- mitted volume prescribed by the table, sure (psig) at 115 °F. must not exceed paragraph (a) of this section. Loading the design pressure of the cargo tank shall be stopped when the device func- or portable tank container. The outage tions. and filling limits for liquefied gases (g) Containers, the liquid level of must be as prescribed in § 173.24b of this which has been determined by means of part, except that this requirement does a fixed length dip tube gauging device, not apply to: shall not be acceptable for stowage as (1) A tank containing carbon dioxide, cargo on vessels in commerce subject refrigerated liquid or nitrous oxide, refrig- to the jurisdiction of the United States erated liquid. Such tank is required to Coast Guard. Nothing contained in this be equipped with suitable pressure con- section shall be so construed as to pro- trol valves and may not be filled to a hibit the transportation on car floats

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or car ferries of motor vehicles laden Kind of gas Gaging device permitted with containers nor cargo tanks the for filling purposes liquid level of either of which has been Sulfur dioxide ...... Fixed length dip tube. determined by means of fixed length Vinyl chloride ...... None. dip tube devices. Vinyl fluoride, inhibited ...... Do. (h) Each cargo tank and portable tank, except a tank filled by weight, (1) The design pressure of the liquid must be equipped with one or more of level gauging devices shall be at least the gauging devices described in the equal to the design pressure of the tank. following table which indicate accu- (2) If the primary gauging device is rately the maximum permitted liquid adjustable, it must be capable of ad- level. Additional gauging devices may justment so that the end of the tube be installed but may not be used as pri- will be in the location specified in mary controls for filling of cargo tanks paragraph (h)(3) of this section for at and portable tanks. Gauge glasses are least one of the ladings to be trans- not permitted on any cargo tank or ported, at the filling level cor- portable tank. Primary gauging de- responding to an average loading tem- vices used on cargo tanks of less than perature. Exterior means must be pro- 3500 gallons water capacity are exempt vided to indicate this adjustment. The from the longitudinal location require- gauging device must be legibly and per- ments specified in paragraphs (h)(2) manently marked in increments not and (3) of this section provided: The exceeding 20 Fahrenheit degrees (or not tank length does not exceed three exceeding 25 p.s.i.g. on tanks for carbon times the tank diameter; and the cargo dioxide, refrigerated liquid or nitrous tank is unloaded within 24 hours after oxide, refrigerated liquid), to indicate each filling of the tank. the maximum levels to which the tank Gaging device permitted may be filled with liquid at tempera- Kind of gas for filling purposes tures above 20 °F. However, if it is not practicable to so mark the gauging de- Anhydrous ammonia ...... Rotary tube; adjustable slip tube; fixed length vice, this information must be legibly dip tube. and permanently marked on a plate af- Anhydrous dimethylamine ...... None. fixed to the tank adjacent to the gaug- Anhydrous monomethylamine ...... Do. Anhydrous trimethylamine ...... Do. ing device. Aqua ammonia solution con- Rotary tube; adjustable (3) A dip tube gauging device consists taining anhydrous ammonia. slip tube; fixed length of a pipe or tube with a valve at its dip tube. outer end with its intake limited by an Butadiene, stabilized ...... Do. Carbon dioxide, refrigerated liquid Do. orifice not larger than 0.060 inch in di- Chlorine ...... None. ameter. If a fixed length dip tube is Dichlorodifluoromethane ...... Do. used, the intake must be located mid- Difluoroethane ...... Do. Difluoromonochloroethane ...... Do. way of the tank both longitudinally Dimethyl ether ...... Do. and laterally and at maximum per- Ethane, refrigerated liquid ...... Rotary tube; adjustable mitted filling level. In tanks for lique- slip tube; fixed length fied petroleum gases, the intake must dip tube. Ethane-propane mixture, refrig- Do. be located at the level reached by the erated liquid. lading when the tank is loaded to max- Hexafluoropropylene ...... None. imum filling density at 40 °F. Hydrogen chloride, refrigerated Do. liquid. (4) Except on a tank used exclusively Liquefied petroleum gases ...... Rotary tube; adjustable for the transportation of carbon diox- slip tube; fixed length ide, refrigerated liquid or nitrous dip tube. oxide, refrigerated liquid, each opening Methyl chloride ...... Fixed length dip tube. Methyl mercaptan ...... Rotary tube; adjustable for a pressure gauge must be restricted slip tube; fixed length at or inside the tank by an orifice no dip tube. larger than 0.060 inch in diameter. For Monochlorodifluoromethane ...... None. Nitrous oxide, refrigerated liquid .. Rotary tube; adjustable carbon dioxide, refrigerated liquid or slip tube; fixed length nitrous oxide, refrigerated liquid serv- dip tube. ice, the pressure gauge need only be Methylacetylenepropadiene, sta- Do. used during the filling operation. bilized. Refrigerant gas, n.o.s. or Dispers- None. (i) Each tank must be provided with ant gas, n.o.s. one or more pressure relief devices

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which, unless otherwise specified in graph (a) of this section for the gas this part, must be of the spring-loaded transported. For UN portable tanks type. Each valve must be arranged to used for liquefied compressed gases and discharge upward and unobstructed to constructed in accordance with the re- the outside of the protective housing to quirements of § 178.276 of this sub- prevent any impingement of escaping chapter, the pressure relief device(s) gas upon the tank. For each chlorine must conform to § 178.276(e) of this sub- tank the protective housing must be in chapter. compliance with the requirements set (4) Except for UN portable tanks, forth in the applicable specification. each safety relief valve must be plainly (1) The safety relief valves on each and permanently marked with the tank must meet the following condi- pressure in p.s.i.g. at which it is set to tions: discharge, with the actual rate of dis- (i) The total relieving capacity, as charge of the device in cubic feet per determined by the flow formulas con- minute of the gas or of air at 60 °F (15.6 tained in Section 5 of CGA S–1.2 (IBR, °C) and 14.7 p.s.i.a., and with the manu- see § 171.7 of this subchapter), must be facturer’s name or trade name and sufficient to prevent a maximum pres- catalog number. The start-to-discharge sure in the tank of more than 120 per- valve marking must be visible after the cent of the design pressure; valve is installed. The rated discharge (ii) The flow capacity rating, testing capacity of the device must be deter- and marking must be in accordance mined at a pressure of 120% of the de- with Sections 5, 6 and 7 of CGA Pam- sign pressure of the tank. For UN port- phlet S–1.2. able tanks, each pressure relief device (iii) For an insulated tank, the re- must be clearly and permanently quired relieving capacity of the relief marked as specified in § 178.274(f)(1) of devices must be the same as for an this subchapter. uninsulated tank, unless the insulation (5) Each safety relief valve must have will remain in place and will be effec- direct communication with the vapor tive under fire conditions. In this case, space in the tank. except for UN portable tanks, each in- (6) Each connection to a safety relief sulated tank must be covered by a valve must be of sufficient size to pro- sheet metal jacket of not less than 16 vide the required rate of discharge gauge thickness. For UN portable through the safety relief valve. tanks where the relieving capacity of (7) [Reserved] the valves has been reduced on the (8) Each pressure relief valve outlet basis of the insulation system, the in- must be provided with a protective de- sulation system must remain effective vice to prevent the entrance and accu- at all temperatures less than 649 °C mulation of dirt and water. This device (1200.2 °F) and be jacketed with a mate- must not impede flow through the rial having a melting point of 700 °C valve. Pressure relief devices must be (1292.0 °F) or greater. designed to prevent the entry of for- (iv) An MC 330 cargo tank that has eign matter, the leakage of liquid and relief valves sized by Fetterly’s for- the development of any dangerous ex- mula dated November 27, 1928, may be cess pressure. continued in service. (9) On tanks for carbon dioxide, re- (2) Each safety relief valve must be frigerated liquid or nitrous oxide, re- arranged to minimize the possibility of frigerated liquid each safety relief de- tampering. If the pressure setting or vice must be installed and located so adjustment is external to the valve, that the cooling effect of the contents the safety relief valve must be provided will not prevent the effective operation with means for sealing the adjustment of the device. In addition to the re- and it must be sealed. quired safety relief valves, these tanks (3) Each safety relief valve on a port- may be equipped with one or more able tank, other than a UN portable pressure controlling devices. tank, must be set to start-to-discharge (10) Each tank for carbon dioxide, re- at pressure no higher than 110% of the frigerated liquid also may be equipped tank design pressure and no lower than with one or more non-reclosing pres- the design pressure specified in para- sure relief devices set to function at a

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pressure not over two times nor less prevent relative motion while in tran- than 1.5 times the design pressure of sit. Valves or other fittings must be the tank. adequately protected against damage (11) Each portion of connected liquid during transportation. (See § 177.834(a) piping or hose that can be closed at of this subchapter). both ends must be provided with a safe- (2) Storage containers with a water ty relief valve without an intervening capacity not exceeding 500 gallons shut-off valve to prevent excessive hy- charged with liquefied petroleum gas drostatic pressure that could burst the to more than five percent of their ca- piping or hose. pacity and intended for permanent in- (12) Subject to conditions of para- stallation on consumer premises may graph (a) of this section for the methyl be transported by private motor carrier chloride and sulfur dioxide optional one-way only from the consumer’s portable tanks, one or more fusible premises to the container owner’s near- plugs examined by the Bureau of Ex- est facility under the following condi- plosives and approved by the Associate tions: Administrator may be used on these (i) Each container must be con- tanks in place of safety relief valves of structed in compliance with the re- the spring-loaded type. The fusible plug quirements in Section VIII of the or plugs must be in accordance with ASME Code and must be marked to in- CGA Pamphlet S–1.2, to prevent a pres- dicate compliance in the manner speci- sure rise in the tank of more than 120 fied by the respective Code. percent of the design pressure. If the (ii) Maximum permitted filling den- tank is over 30 inches long, each end sity may not exceed that specified in must have the total specified safety paragraph (b) of this section. discharge area. (iii) Prior to loading on a motor vehi- (13) A safety relief valve on a chlo- cle, the container must be inspected by rine cargo tank must conform to one of a trained and qualified person for the following standards of The Chlorine leaks, corroded or abraded areas, dents, Institute, Inc.: Type 1 1⁄2 JQ225, Dwg. distortions, weld defects, or other con- H51970 (IBR, see § 171.7 of this sub- dition that may render the container chapter); or Type 1 1⁄2 JQ225, Dwg. unsafe for transportation. A record of H50155 (IBR, see § 171.7 of this sub- the inspection must be legibly signed chapter). and dated by the person performing the (j) Consumer storage containers. (1) inspection and retained by the con- Storage containers for liquefied petro- tainer owner for two years. The signa- leum gas or propane charged to five ture on the inspection record rep- percent of their capacity or less and in- resents a certification that the con- tended for permanent installation on tainer has been inspected and has no consumer premises may be shipped by defects that would render it unsafe for private motor carrier under the fol- transportation under the HMR. The lowing conditions: record of inspection must include the (i) Each container must be con- date of inspection, the inspector’s constructed in compliance with the re- tact information (such as a telephone quirements in Section VIII of the number), the container’s serial number ASME Code (IBR, see § 171.7 of this sub- and container size (water capacity), es- chapter) and must be marked to indi- timated amount of hazardous material, cate compliance in the manner speci- and the origin and destination of ship- fied by the respective Code. Containers ment. built in compliance with earlier edi- (iv) Only one storage container may tions starting with 1943 are authorized. be transported on a motor vehicle. (ii) Each container must be equipped (v) For loading on a motor vehicle, with safety devices in compliance with the container must be lifted by slings, the requirements for safety devices on which must be completely wrapped containers as specified in NFPA 58, around the container. Lifting lugs may Liquefied Petroleum Gas Code (IBR, not be used. The slings must be rated see § 171.7 of this subchapter). to a weight sufficient to accommodate (iii) The containers must be braced or the container and its lading and shall otherwise secured on the vehicle to comply with ASME B30.9 on slings used

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for lifting purposes, and must be vis- (5) It must be inspected, tested, and ually inspected prior to each use. A equipped in accordance with subpart E sling showing evidence of tears, fray- of part 180 of this subchapter as speci- ing, or other signs of excessive wear fied for MC 331 cargo tank motor vehi- may not be used. cles. (vi) The storage container must be (6) Except as provided in this para- secured on a motor vehicle so that the graph (k), it must be operated exclu- container is completely within the en- sively in intrastate commerce, includ- velope of the vehicle and does not ex- ing its operation by a motor carrier tend beyond the vehicle frame. otherwise engaged in interstate com- (vii) The storage container must be merce, in a state where its operation placed on the vehicle in a manner, such was permitted by law (not including as in a cradle, which ensures that no the incorporation of this subchapter) weight is placed on the supporting legs prior to January 1, 1981. A cargo tank during transportation. motor vehicle operating under author- (viii) The storage container must be ity of this section may cross state lines secured against movement during to travel to and from a qualified assem- transportation. Bracing must conform bly, repair, maintenance, or requali- with the requirements of paragraph fication facility. The cargo tank need (j)(1)(iii) of this section and § 177.834(a) not be cleaned and purged, but it may of this subchapter and with Section 6– not contain liquefied petroleum gas in 5.2 of NFPA 58, Liquefied Petroleum excess of five percent of the water ca- Gas Code. Straps or chains used as tie- pacity of the cargo tank. If the vehicle downs must be rated to exceed the engine is supplied fuel from the cargo maximum load to be transported and tank, enough fuel in excess of five per- conform to the requirements in cent of the cargo tank’s water capacity §§ 393.100 through 393.106 of this title. may be carried for the trip to or from (ix) Tow trailers used to transport the facility. storage containers in accordance with (7) It must have been used to trans- this paragraph (j)(2) must provide rear port liquefied petroleum gas prior to end protection that conforms to re- January 1, 1981. quirements in § 393.86 of this title. (8) It must be operated in conform- (3) Storage containers of less than ance with all other requirements of 1,042 pounds water capacity (125 gal- this subchapter. lons) may be shipped when charged (l) Anhydrous ammonia must not be with liquefied petroleum gas in compli- offered for transportation or trans- ance with DOT filling density. ported in specification MC 330 and MC (k) A nonspecification cargo tank 331 cargo tanks constructed of meeting, and marked in conformance quenched and tempered (‘‘QT’’) steel with, the edition of Section VIII of the except as provided in this paragraph. ASME Code in effect when it was fab- (1) The ammonia must have a min- ricated may be used for the transpor- imum water content of 0.2 percent by tation of liquefied petroleum gas pro- weight. Any addition of water must be vided it meets all of the following con- made using steam condensate, deion- ditions: ized, or distilled water. (1) It must have a minimum design (2) Except as otherwise provided in pressure no lower than 250 psig. this paragraph, each person offering for (2) It must have a capacity of 13,247.5 transportation or transporting anhy- L (3,500 water gallons) or less. drous ammonia shall perform a peri- (3) It must have been manufactured odic analysis for prescribed water con- in conformance with Section VIII of tent in the ammonia. The analysis the ASME Code prior to January 1, must be performed: 1981, according to its ASME name plate (i) From a sample of the ammonia in and manufacturer’s data report. storage taken at least once every 7 (4) It must conform to the applicable days, or each time ammonia is added to provisions of NFPA 58, except to the the storage tanks, whichever is less extent that provisions in NFPA 58 are frequent; or inconsistent with requirements in (ii) At the time the cargo tanks are parts 178 and 180 of this subchapter. loaded, then a sample of the ammonia

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taken from at least one loaded cargo Code in effect at the time it was manu- tank out of each 10 loads, or from one factured, and is marked with a valid cargo tank every 24 hours, whichever is ASME plate. less frequent; or (ii) Is equipped with pressure relief (iii) At the same frequency as de- valves meeting the requirements of scribed in paragraph (l)(2)(ii) of this CGA Standard S–1.2 (IBR, see § 171.7 of section, from a sample taken from the this subchapter); loading line to the cargo tank. (iii) Is painted white or aluminum; (3) If water is added at the time of (iv) Has a capacity of 3,000 gallons or loading: less; (i) The sample for analysis must be (v) Is loaded to a filling density no taken from a point in the loading line greater than 56 percent; between the water injection equipment (vi) Is securely mounted on a farm and the cargo tank; and wagon or meets paragraph (m)(3) of (ii) Positive provisions must be made this section; and to assure water injection equipment is operating. (vii) Is in conformance with the re- (4) If water injection equipment be- quirements of part 172 of this sub- comes inoperative, suitable corrective chapter except that shipping papers are maintenance must be performed after not required; and it need not be which a sample from the first loaded marked or placarded on one end if that cargo tank must be analyzed for pre- end contains valves, fittings, regu- scribed water content. lators or gauges when those appur- (5) The analysis method for water tenances prevent the markings and content must be as prescribed in CGA placard from being properly placed and G–2.2, ‘‘Tentative Standard Method for visible. Determining Minimum of 0.2 percent (2) Nurse tanks with missing or illegible water in Anhydrous Ammonia,’’ (IBR, ASME plates. Nurse tanks with missing see § 171.7 of this subchapter). or illegible ASME plates may continue (6) Records indicating the results of to be operated provided they conform the analysis taken, as required by this to the following requirements: paragraph, must be retained for 2 years (i) Each nurse tank must undergo an and must be open to inspection by a external visual inspection and testing representative of the Department. in accordance with § 180.407(d) of this (7) Each person receiving anhydrous subchapter. ammonia containing 0.2 per cent water (ii) Each nurse tank must be thick- by weight may offer for transportation ness tested in accordance with or transport that ammonia without § 180.407(i) of this subchapter. A nurse performing the prescribed analysis for tank with a capacity of less than 1,500 water content provided: gallons must have a minimum head (i) The ammonia received was cer- thickness of 0.203 inch and a minimum tified as containing 0.2 percent water shell thickness of 0.239 inch. A nurse as prescribed in §§ 172.203(h)(l)(i) and tank with a capacity of 1,500 gallons or 177.817(a) of this subchapter; and more must have a minimum thickness (ii) The amount of water in the am- of 0.250 inch. Any nurse tank with a monia has not been reduced by any thickness test reading of less than that means. specified in this paragraph at any point (m) General. (1) A cargo tank that is must be removed from hazardous mate- commonly known as a nurse tank and rials service. considered an implement of husbandry (iii) Each nurse tank must be pres- transporting anhydrous ammonia and sure tested in accordance with operated by a private motor carrier ex- § 180.407(g) of this subchapter. The min- clusively for agricultural purposes is imum test pressure is 375 psig. Pneu- excepted from the specification re- matic testing is not authorized. quirements of part 178 of this sub- (iv) Each nurse tank must be in- chapter if it: spected and tested by a person meeting (i) Has a minimum design pressure of the requirements of § 180.409(d) of this 250 psig, meets the requirements of the subchapter. Furthermore, each nurse edition of Section VIII of the ASME tank must have the tests performed at

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least once every five years after the (ii) The tank is inspected and tested completion of the initial tests. in accordance with subpart E of part (v) After each nurse tank has suc- 180 of this subchapter as specified for cessfully passed the visual, thickness, an MC 331 cargo tank; and pressure tests, welded repairs on (iii) The tank is restricted to rural the tank are prohibited. roads in areas within 50 miles of the (vi) After the nurse tank has success- fertilizer distribution point where the fully passed the visual, thickness, and nurse tank is loaded; and pressure tests, it must be marked in (iv) For the purposes of this section, accordance with § 180.415(b), and perma- a field truck means a vehicle on which nently marked near the test and in- a nurse tank is mounted that is de- spection markings with a unique own- signed to withstand off-road driving on er’s identification number in letters hilly terrain. Specifically, the vehicle must be outfitted with stiffer suspen- and numbers at least 1⁄2 inch in height sion (for example, additional springs or and width. airbags) than would be necessary for a (vii) Each nurse tank owner must comparable on-road vehicle, a rear axle maintain a copy of the test inspection ratio that provides greater low end report prepared by the inspector. The torque, and a braking system and tires test report must contain the results of designed to ensure stability in hilly the test and meet the requirements in terrain. The field truck must have low § 180.417(b) and be made available to a annual over-the-road mileage and be DOT representative upon request. used exclusively for agricultural pur- (3) Field truck mounted tanks. A non- poses. DOT specification cargo tank (nurse (n) Emergency discharge control for tank) securely mounted on a field cargo tank motor vehicles in liquefied truck is authorized under the following compressed gas service—(1) Required conditions: emergency discharge control equipment. (i) The tank is in conformance with Each cargo tank motor vehicle in liq- all the requirements of paragraph uefied compressed gas service must (m)(1) of this section, except that the have an emergency discharge control requirement in paragraph (m)(1)(vi) capability as specified in the following does not apply; table:

Required emergency discharge control § 173.315(n)(1)(*) Material Delivery service capability

(i) ...... Division 2.2 materials with no All ...... None. subsidiary hazard, excluding anhydrous ammonia.

(ii) ...... Division 2.3 materials ...... All ...... Paragraph (n)(2) of this section.

(iii) ...... Division 2.2 materials with a Other than metered delivery Paragraph (n)(2) of this section. subsidiary hazard, Division service. 2.1 materials, and anhydrous ammonia.

(iv) ...... Division 2.2 materials with a Metered delivery service ...... Paragraph (n)(3) of this section. subsidiary hazard, Division 2.1 materials, and anhydrous ammonia in a cargo tank motor vehicle with a capacity of 13,247.5 L (3,500 water gallons) or less.

(v) ...... Division 2.2 materials with a Metered delivery service ...... Paragraph (n)(3) of this section, and, for subsidiary hazard, Division obstructed view deliveries where per- 2.1 materials, and anhy- mitted by § 177.840(p) of this sub- drous ammonia in a cargo chapter, paragraph (n)(2) or (n)(4) of tank motor vehicle with a ca- this section. pacity greater than 13,247.5 L (3,500 water gallons).

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Required emergency discharge control § 173.315(n)(1)(*) Material Delivery service capability

(vi) ...... Division 2.2 materials with a Both metered delivery and Paragraph (n)(2) of this section, pro- subsidiary hazard, Division other than metered delivery vided the system operates for both 2.1 materials, and anhy- service. metered and other than metered deliv- drous ammonia in a cargo eries; otherwise, paragraphs (n)(2) tank with a capacity of great- and (n)(3) of this section. er than 13,247.5 L (3,500 water gallons).

(2) Cargo tank motor vehicles in other tion, a cargo tank motor vehicle must than metered delivery service. A cargo have an off-truck remote means to tank motor vehicle in other than me- close the internal self-closing stop tered delivery service must have a valve and shut off all motive and auxil- means to automatically shut off the iary power equipment upon activation flow of product without the need for by a qualified person attending the un- human intervention within 20 seconds loading of the cargo tank motor vehi- of an unintentional release caused by a cle (off-truck remote shut-off). It must complete separation of a liquid deliv- function reliably at a distance of 45.72 ery hose (passive shut-down capa- m (150 feet). The off-truck remote shut- bility). off activation device must not be capa- (i) Designed flow of product through a bypass in the valve is acceptable ble of reopening the internal self-clos- when authorized by this subchapter. ing stop valve after emergency activa- (ii) The design for the means to auto- tion. matically shut off product flow must (i) The emergency discharge control be certified by a Design Certifying En- equipment must be installed under the gineer. The certification must consider supervision of a Registered Inspector. any specifications of the original com- Each wireless transmitter/receiver ponent manufacturer and must explain must be tested to demonstrate that it how the passive means to shut off the will close the internal self-closing stop flow of product operates. It must also valve and shut off all motive and auxil- outline the parameters (e.g., tempera- iary power equipment at a distance of ture, pressure, types of product) within 91.44 m (300 feet) under optimum condi- which the passive means to shut off the tions. Emergency discharge control flow of product is designed to operate. equipment that does not employ a All components of the discharge sys- wireless transmitter/receiver must be tem that are integral to the design tested to demonstrate its functioning must be included in the certification. A at the maximum length of the delivery copy of the design certification must hose. be provided to the owner of the cargo (ii) The Registered Inspector must tank motor vehicle on which the equip- certify that the remote control equipment will be installed. ment is installed in accordance with (iii) Installation must be performed the original component manufacturer’s under the supervision of a Registered specifications and is tested in accord- Inspector unless the equipment is in- ance with paragraph (n)(3)(i) of this stalled and removed as part of regular operation (e.g., a hose). The Registered section. The Registered Inspector must Inspector must certify that the equip- provide the owner of the cargo tank ment is installed and tested, if it is motor vehicle with this certification. possible to do so without damaging the (4) Query systems. When a trans- equipment, in accordance with the De- mitter/receiver system is used to sat- sign Certifying Engineer’s certifi- isfy the requirements of paragraph cation. The Registered Inspector must (n)(1)(v) of this section, it must close provide the certification to the owner the internal self-closing stop valve and of the cargo tank motor vehicle. shut off all motive and auxiliary power (3) Cargo tank motor vehicles in metered equipment unless the qualified person delivery service. When required by the attending the unloading operation pre- table in paragraph (n)(1) of this sec- vents it from doing so at least once

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every five minutes. Testing and certifi- retest in § 180.407(c) of this subchapter. cation must be as specified in para- Prior to each loading, the cargo tank graph (n)(3) of this section. motor vehicle must be inspected and (5) Compliance dates. (i) Each speci- the angle valves and gasketed joints fication MC 331 cargo tank motor vehi- must be examined and tested at a pres- cle with a certificate of construction sure of not less than 50 psig to deter- issued two or more years after July 1, mine that they are not leaking and are 1999, must have an appropriate emer- in proper condition for transportation. gency discharge control capability as Any leaks must be corrected before the specified in this paragraph (n). cargo tank motor vehicle is offered for (ii) No MC 330, MC 331, or nonspeci- transportation. fication cargo tank motor vehicle au- (3) Excess flow valves on the cargo thorized under paragraph (k) of this tank motor vehicle must meet the re- section may be operated unless it has quirements of paragraph (n) of this sec- an appropriate emergency discharge tion. control capability as specified in this (p) Fusible elements. Each MC 330, MC paragraph (n) no later than the date of 331, or nonspecification cargo tank au- its first scheduled pressure retest re- thorized under paragraph (k) of this quired after July 1, 2001. No MC 330, MC section must have a thermal means of 331 or nonspecification cargo tank closure for each internal self-closing motor vehicle authorized under para- stop valve as specified in § 178.337– graph (k) of this section may be oper- 8(a)(4) of this subchapter. ated after July 1, 2006, unless it has (q) Manifolding is authorized for been equipped with emergency dis- cargo tanks containing anhydrous am- charge control equipment as specified monia provided each individual cargo in this paragraph (n). tank is equipped with a pressure relief (iii) No MC 330 or MC 331 cargo tank device or valves and gauging devices as motor vehicle with a capacity over required by paragraphs (h) and (i) of 13,247 L (3,500 gallons) used in metered this section. Each valve must be tight- delivery service may be operated un- ly closed while the cargo tank is in less it has an appropriate discharge transit. Each cargo tank must be filled control capability as specified in this separately. paragraph (n) no later than July 1, 2003, [29 FR 18743, Dec. 29, 1964. Redesignated at 32 or the date of its first scheduled pres- FR 5606, Apr. 5, 1967] sure retest required after July 1, 2001, whichever is earlier. EDITORIAL NOTE: For FEDERAL REGISTER ci- tations affecting § 173.315, see the List of CFR (o) Chlorine cargo tank motor vehicles. Sections Affected, which appears in the Each cargo tank motor vehicle used for Finding Aids section of the printed volume the transportation of chlorine must and at www.fdsys.gov. meet the requirements in the following: § 173.316 Cryogenic liquids in cyl- (1) Any hose, piping, or tubing used inders. for loading or unloading that is mount- (a) General requirements. (1) A cyl- ed or carried on the motor vehicle may inder may not be loaded with a cryo- not be attached to any valve and must genic liquid colder than the design be capped at all ends to prevent the service temperature of the packaging. entry of moisture, except at the time (2) A cylinder may not be loaded with of loading or unloading. Except at the any material which may combine time of loading and unloading, the pipe chemically with any residue in the connection of each angle valve must be packaging to produce an unsafe condi- closed with a screw plug which is tion. chained or otherwise fastened to pre- (3) The jacket covering the insulation vent misplacement. on a cylinder used to transport any (2) Each chlorine cargo tank motor flammable cryogenic liquid must be vehicle angle valve must be tested to made of steel. be leak free at not less than 225 psig (4) A valve or fitting made of alu- using dry air or inert gas before instal- minum with internal rubbing or abrad- lation and thereafter every 2 years ing aluminum parts that may come in when performing the required periodic contact with oxygen in the cryogenic

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