Piping classification according to service.

  1. Law
  2. CFR 46
  3. Shipping
  4. Coast Guard, Department of Homeland Security
  5. Marine Engineering
  6. Piping Systems and Appurtenances
  7. Piping Classification
  8. Piping classification according to service.

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§ 56.04-2 Piping classification according to service.

The designation of classes according to service is found in table 56.04-2.

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Table 56.04-2 - Pressure Piping Classification

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.
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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.

1 Where doubt exists as to proper classification, refer to the Commandant for resolution.

2 For 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).

3 Not 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]


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