46 CFR § 56.04-2
Piping classification according to service
April 15, 2021
The designation of classes according to service is found in table 56.04-2.
Table 56.04-2—Pressure Piping Classification
Open Table
Service | Class1 | Pressure (p.s.i.g.) | Temp. (°F) | |
---|---|---|---|---|
Class B and C poisons2 | I | any | and | 0 and above. |
I-L | any | and | below 0. | |
II | (3) | (3) | (3) | |
II-L | (3) | (3) | (3) | |
Gases and vapors2 | I | above 150 | or | above 650. |
I-L | above 150 | and | below 0. | |
II | 150 and below | and | 0 to 650. | |
II-L | 150 and below | and | below 0. | |
Liquefied flammable gases2 | I | above 150 | and | 0 and above.1 |
I-L | above 150 | and | below 0. | |
II | 150 and below | and | 0 and above. | |
II-L | 150 and below | and | below 0. | |
Molten sulphur | I | above 225 | or | above 330. |
II | 225 and below | and | 330 and below. | |
Cargo liquids Grades A through D2 | I | above 225 | or | above 150. |
I-L | above 225 | and | below 0. | |
II | 225 and below | and | 0 to 150. | |
II-L | 225 and below | and | below 0. | |
Cargo liquids Grade E | I | above 225 | or | above 400. |
I-L | above 225 | and | below 0. | |
II | 225 and below | and | 0 to 400. | |
II-L | 225 and below | and | below 0. | |
Water | I | above 225 | or | above 350. |
II | 225 and below | and | 350 and below. | |
Fuels (Bunker, diesel, gasoline, etc.) | I | above 150 | or | above 150. |
II | 150 and below | and | 150 and below. | |
Lubricating oil | I | above 225 | or | above 400. |
II | 225 and below | and | 400 and below. | |
Asphalt | I | above 225 | or | above 400. |
II | 225 and below | and | 400 and below. | |
Heat transfer oil | I | above 225 | or | above 400. |
II | 225 and below | and | 400 and below. | |
Hydraulic fluid | I | above 225 | or | above 400. |
II | 225 and below | and | 400 and below. |
Open Table
Flammable or combustible dangerous cargoes. | Refer to specific requirements of part 40 of this chapter. |
Other dangerous cargoes. | Refer to specific requirements of part 98 of this chapter. |
1Where doubt exists as to proper classification, refer to the Commandant for resolution.
2For definitions, see 46 CFR parts 30, 151, and 154. Note that the category “B and C” poisons is not used in the rules applying to self-propelled vessels (46 CFR part 153).
3Not permitted except inside cargo tanks approved for Class B and C poisons.
[CGFR 68-82, 33 FR 18843, Dec. 18, 1968, as amended by CGD 73-254, 40 FR 40164, Sept. 2, 1975; CGD 73-96, 42 FR 49024, Sept. 26, 1977]