Source: https://www.govregs.com/regulations/49/173.319
Timestamp: 2019-04-19 21:19:29+00:00

Document:
49 CFR 173.319 - Cryogenic liquids in tank cars. § 173.319 - Cryogenic liquids in tank cars.
§ 173.319 - Cryogenic liquids in tank cars.
(a) General requirements. (1) A tank car containing a flammable cryogenic liquid may not be shipped unless it was loaded by, or with the consent of, the owner of the tank car.
(2) The amount of flammable cryogenic liquid loaded into a tank car must be determined, either by direct measurement or by calculation based on weight, to verify that the tank has not been filled to a level in excess of the limits specified in paragraph (d)(2) of this section. The weight of any flammable cryogenic liquid loaded, except hydrogen, must be checked by use of scales after disconnecting the loading line.
(3) The shipper must notify the Federal Railroad Administration whenever a tank car containing any flammable cryogenic liquid is not received by the consignee within 20 days from the date of shipment. Notification to the Federal Railroad Administration may be made by email to HMassist@dot.gov or telephone call to (202) 493-6245.
(iv) Unless it is marked with the name of contents, in accordance with § 172.330 of this subchapter.
(2) The absolute pressure in the annular space must be less than 75 microns of mercury.
(c) Temperature. A flammable cryogenic liquid must be loaded into a tank car at such a temperature that the average daily pressure rise during transportation will not exceed 3 psig (see paragraph (a)(4)(iii) of this section).
Design service temperature Minus 260 °F Minus 260 °F Minus 155 °F Minus 423 °F.
Specification (see § 180.507(b)(3) of this subchapter) 113D60W, 113C60W 113C120W 113D120W 113A175W, 113A60W.
(e) Special requirements for class DOT 113 tank cars - (1) A class DOT-113 tank car need not be periodically pressure tested; however, each shipment must be monitored to determine the average daily pressure rise in the tank car. If the average daily pressure rise during any shipment exceeds 0.2 Bar (3 psig) per day, the tank must be tested for thermal integrity prior to any subsequent shipment.
(D) 500.09 joules (0.4740 Btu/day/lb) of inner tank car water capacity, for DOT-113D120W tank cars.
(3) A tank car that fails a test prescribed in paragraph (e)(2) of this section must be removed from hazardous materials service. A tank car removed from hazardous materials service because it failed a test prescribed in paragraph (e)(2) of this section may not be used to transport a hazardous material unless the tank car conforms to all applicable requirements of this subchapter.
(4) Each rupture disc must be replaced every 12 months, and the replacement date must be marked on the car near the pressure relief valve information.
(5) Pressure relief valves and alternate pressure relief valves must be tested every five years. The start-to-discharge pressure and vapor tight pressure requirements for the pressure relief valves must be as specified in § 179.401-1 of this subchapter. The alternate pressure relief device values specified in § 179.401-1 of this subchapter for a DOT-113C120W tank car apply to a DOT-113D120W tank car.

References: § 173

§ 173
 § 172
 § 180
 § 179
 § 179