49 CFR 172.102 Special Provisions — TP-Codes
49 CFR 172.102 TP-codes — provisions for IM and UN Specification portable tanks.
Excerpts from 49 CFR §172.102. Verify against the current official rule text before relying on them.
| Code | Description | Open |
|---|---|---|
TP1 | The maximum degree of filling must not exceed the degree of filling determined by the following:![]() Where: tr is the maximum mean bulk temperature during transport, and tf is the temperature in degrees celsius of the liquid during filling. | View |
TP2 | a. The maximum degree of filling must not exceed the degree of filling determined by the following:![]() Where: tr is the maximum mean bulk temperature during transport, tf is the temperature in degrees celsius of the liquid during filling, and α is the mean coefficient of cubical expansion of the liquid between the mean temperature of the liquid during filling (tf) and the maximum mean bulk temperature during transportation (tr) both in degrees celsius. b. For liquids transported under ambient conditions α may be calculated using the formula: ![]() Where: d15 and d50 are the densities (in units of mass per unit volume) of the liquid at 15 °C (59 °F) and 50 °C (122 °F), respectively. | View |
TP3 | The maximum degree of filling (in %) for solids transported above their melting points and for elevated temperature liquids shall be determined by the following:![]() Where: df and dr are the mean densities of the liquid at the mean temperature of the liquid during filling and the maximum mean bulk temperature during transport respectively. | View |
TP4 | The maximum degree of filling for portable tanks must not exceed 90%. | View |
TP5 | For a portable tank used for the transport of flammable refrigerated liquefied gases or refrigerated liquefied oxygen, the maximum rate at which the portable tank may be filled must not exceed the liquid flow capacity of the primary pressure relief system rated at a pressure not exceeding 120 percent of the portable tank's design pressure. For portable tanks used for the transport of refrigerated liquefied helium and refrigerated liquefied atmospheric gas (except oxygen), the maximum rate at which the tank is filled must not exceed the liquid flow capacity of the pressure relief device rated at 130 percent of the portable tank's design pressure. Except for a portable tank containing refrigerated liquefied helium, a portable tank shall have an outage of at least two percent below the inlet of the pressure relief device or pressure control valve, under conditions of incipient opening, with the portable tank in a level attitude. No outage is required for helium. | View |
TP6 | The tank must be equipped with a pressure release device which prevent a tank from bursting under fire engulfment conditions (the conditions prescribed in CGA pamphlet S-1.2 (see §171.7) or alternative conditions approved by the Associate Administrator may be used to consider the fire engulfment condition), taking into account the properties of the hazardous material to be transported. | View |
TP7 | The vapor space must be purged of air by nitrogen or other means. | View |
TP8 | A portable tank having a minimum test pressure of 1.5 bar (150 kPa) may be used when the flash point of the hazardous material transported is greater than 0 °C (32 °F). | View |
TP9 | A hazardous material assigned to special provision TP9 in Column (7) of the §172.101 Table may only be transported in a portable tank if approved by the Associate Administrator. | View |
TP10 | A lead lining, not less than 5 mm thick, which shall be tested annually, or another suitable lining material approved by the competent authority, is required. A portable tank may be offered for transport after the date of expiry of the last lining inspection for a period not to exceed three months for purposes of performing the next required test or inspection, after emptying but before cleaning. | View |
TP12 | This material is considered highly corrosive to steel. | View |
TP13 | Self-contained breathing apparatus must be provided when this hazardous material is transported by sea. | View |
TP16 | The portable tank must be protected against over and under pressurization which may be experienced during transportation. The means of protection must be approved by the approval agency designated to approve the portable tank in accordance with the procedures in part 107, subpart E, of this subchapter. The pressure relief device must be preceded by a frangible disk in accordance with the requirements in §178.275 to prevent crystallization of the product in the pressure relief device. | View |
TP17 | Only inorganic non-combustible materials may be used for thermal insulation of the tank. | View |
TP18 | The temperature of this material must be maintained between 18 °C (64.4 °F) and 40 °C (104 °F) while in transportation. Portable tanks containing solidified methacrylic acid must not be reheated during transportation. | View |
TP19 | The calculated wall thickness must be increased by 3 mm at the time of construction. Wall thickness must be verified ultrasonically at intervals midway between periodic hydraulic tests (every 2.5 years). The portable tank must not be used if the wall thickness is less than that prescribed by the applicable T code in Column (7) of the Table for this material. | View |
TP20 | This hazardous material must only be transported in insulated tanks under a nitrogen blanket. | View |
TP21 | The wall thickness must not be less than 8 mm. Portable tanks must be hydraulically tested and internally inspected at intervals not exceeding 2.5 years. | View |
TP22 | Lubricants for portable tank fittings (for example, gaskets, shut-off valves, flanges) must be oxygen compatible. | View |
TP24 | The portable tank may be fitted with a device to prevent the build up of excess pressure due to the slow decomposition of the hazardous material being transported. The device must be in the vapor space when the tank is filled under maximum filling conditions. This device must also prevent an unacceptable amount of leakage of liquid in the case of overturning. | View |
TP25 | Sulphur trioxide 99.95% pure and above may be transported in tanks without an inhibitor provided that it is maintained at a temperature equal to or above 32.5 °C (90.5 °F). | View |
TP26 | The heating device must be exterior to the shell. For UN 3176, this requirement only applies when the hazardous material reacts dangerously with water. | View |
TP27 | A portable tank having a minimum test pressure of 4 bar (400 kPa) may be used provided the calculated test pressure is 4 bar or less based on the MAWP of the hazardous material, as defined in §178.275, where the test pressure is 1.5 times the MAWP. | View |
TP28 | A portable tank having a minimum test pressure of 2.65 bar (265 kPa) may be used provided the calculated test pressure is 2.65 bar or less based on the MAWP of the hazardous material, as defined in §178.275, where the test pressure is 1.5 times the MAWP. | View |
TP29 | A portable tank having a minimum test pressure of 1.5 bar (150.0 kPa) may be used provided the calculated test pressure is 1.5 bar or less based on the MAWP of the hazardous materials, as defined in §178.275, where the test pressure is 1.5 times the MAWP. | View |



