46 CFR §154.466

1. (a)The insulation for a cargo tank without a secondary barrier must be designed for the cargo tank at the design temperature, and for a vessel operating in:
   1. (1)Any waters in the world, except Alaskan waters, for the ambient cold condition of:
      1. (i)Five knots air at −18 °C (0 °F); and
      2. (ii)Still sea water at 0 °C (32 °F); or
   2. (2)Alaskan waters for the ambient cold condition of:
      1. (i)Five knots air at −29 °C (20 °F); and
      2. (ii)Still sea water at −2 °C (28 °F).
2. (b)The insulation for a cargo tank with a secondary barrier must be designed for the secondary barrier at the design temperature, and the ambient cold conditions listed under paragraph (a)(1) or paragraph (a)(2) of this section.
3. (c)The insulation material must be designed for any loads transmitted from adjacent hull structure.
4. (d)Insulation for cargo tank and piping must meet § 38.05-20 of this chapter.
5. (e)Powder or granulated insulation must:
   1. (1)Not compact from vibrations of the vessel;
   2. (2)Maintain the thermal conductivity listed under § 154.467; and
   3. (3)Not exert a static pressure greater than the external design pressure of the cargo tank under § 154.408.