46 CFR § 174.090 - Permeability of spaces.

When doing the calculations required in § 174.065—

(a) The permeability of a floodable space, other than a machinery space, must be as listed in Table 174.090; and

(b) Calculations in which a machinery space is treated as a floodable space must be based on an assumed machinery space permeability of 85%, unless the use of an assumed permeability of less than 85% is justified in detail.

Table 174.090—Permeability

Spaces and tanks	Permeability (percent)
Storeroom spaces	60.
Accommodation spaces	95.
Voids	95.
Consumable liquid tanks	95 or 0. 1
Other liquid tanks	95 or 0. 2

1 Whichever results in the more disabling condition.

2 If tanks are partially filled, the permeability must be determined from the actual density and amount of liquid carried.