This standard represents the minimum requirements for pressure relief devices considered to be appropriate and adequate for use on cylinders having capacities of 1000 lb (454 kg) of water or less Refer also to Title 49 of the U.S. Code of Federal Regulations (49 CFR) 173.301(f) [1]. This standard also applies to
DOT 3AX , DOT-3AAX, and DOT-3T cylinders having capacities over 1000 lb (454 kg) of water, and which
comply with the design specifications and charging and maintenance regulations of the u S Department of
Transpodahon (DOT) or the corresponding specifications and regulations of Transport Canada (TC) [1.2] This
standard also covers requirements for pressure relief devices for CTC/DOT-4L and TC-4LM ~nsulated cylinders
containing cryogenic liquids. Pressure relief device requirements for multi-unit tank car tanks (DOT106A and
DOT110A-W} are not covered by this standard (see 49 CFR 179.300-15) [1].
This standard includes Tables I to 6, which provide information pertaining to pressure relief devices. Table 1
contains information on the different types of pressure relief devices. Table 2 contains FTSC code classification
for gases. Table 3 contains a listing of gases and their pressure relief device assignments. Table 4 contains
temperature correction factors. Table 5 includes values for basic orifice factors flange taps for flow in cubic feet
per minute. Table 6 contains values of G, and G, for rated burst pressure of rupture disks for CTC/DOT-4L and
TC-4LM cylinders.