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Amendments to Federal Regulations for Testing and Inspection of Cargo Tanks Announced


On June 2, 2016, the U.S. Department of Transportation announced amendments to Code of Federal Regulations Title 49 (49 CFR) §180.407(c) regarding requirements for test and inspection of specification cargo tanks.The amendments are effective on July 5, 2016.

The amendments affect the regulation of MC 331 cargo tanks in dedicated propane service. The applicable regulations in the table in 49 CFR §180.407 are summarized below.

MC 331 Cargo Tank Summary: The Compliance Dates – Inspections and Test Under §180.407(c)

Test or inspection
(cargo tank specification, configuration, and service)

Date by which first test must be completed

Interval period after first test

Interval Visual Inspection:

MC 331 cargo tanks less than 3,500 gallons water capacity in dedicated propane service constructed of nonquenched and tempered NQT SA-612 steel (see Note 5).

September 1, 2016


Pressure Test (Hydrostatic or pneumatic):

MC 331 cargo tanks less than 3,500 gallons water capacity in dedicated propane service constructed of nonquenched and tempered NQT steel (see Note 5).

September 1, 2016


49 CFR §180.407(c) Note 5 states, “A 10-year inspection interval period also applies to cargo tanks constructed of NQT SA-202, NQT SA-455, or NQT SA-612 steels provided the materials have full-size equivalent (FSE) Charpy vee notch (CVN) energy test data that demonstrated 75% shear-area ductility at 32°F with an average of 3 or more samples > 15 ft-lb FSE with no sample <10 ft-lb FSE.”

Cargo tank units that are registered in Texas which will be utilizing this exemption must carry documentation on the units showing the container was manufactured and tested in accordance with Note 5. Units which do not carry the required documentation must be tested every five years. The Pipeline and Hazardous Materials Safety Administration has a similar requirement stating that if a cargo tank owner cannot produce documentation that a MC 331 cargo tank meets the requirements for a ten-year requalification interval, they are subject to the five-year requalification interval.

For further reference 49 CFR §178.337-2(a)(3) requires that a MC 331 fabricator record the heat and slab numbers, as well as the certified Charpy impact values, where required, of each plate used in each cargo tank on a sketch showing the location of each plate in the shell and heads of the cargo tank. Copies of each sketch shall be provided to the owner, retained for at least five years by the fabricator and made available to duly identified representatives of the U.S. Department of Transportation.

For additional information on the amendments, visit the U.S. Department of Transportation website at

If there are questions regarding these amendments, contact the Railroad Commission of Texas’ Alternative Fuels Safety department at