46 CFR §153.233

1. (a)To prevent leakage through a single weld failure, the following spaces must be separated from a cargo by two walls, two bulkheads, or a bulkhead and a deck not meeting in a cruciform joint:
   1. (1)Machinery spaces.
   2. (2)Service spaces.
   3. (3)Accommodation spaces.
   4. (4)Spaces for storing potable domestic, or feed water.
   5. (5)Spaces for storing edibles.
2. (b)Some examples of arrangements that may separate cargo from the spaces listed in paragraph (a) of this section are the following:
   1. (1)Dedicated ballast tanks.
   2. (2)Cargo pumprooms.
   3. (3)Ballast pumprooms.
   4. (4)Tanks not carrying a cargo listed in this part. 3
   5. (5)A cofferdam aft of the cargo containment systems and whose forward bulkhead is forward of any joint common to an accommodations space and the deck.
   6. (6)Double walled piping or a piping tunnel.