38.15-1 Filling of tanks - TB/ALL.§ 38.15-1 Filling of tanks - TB/ALL.
(a) Refrigerated and semirefrigerated tanks shall be filled so that there is an outage of at least 2 percent of the volume of the tank at the temperature corresponding to the vapor pressure of the cargo at the safety relief valve setting. A reduction in the required outage may be permitted by the Commandant when warranted by special design considerations. Normally then, the maximum volume to which a tank may be loaded is:VL = 0.98dr V/dL where: VL = maximum volume to which tank may be loaded. V = volume of tank. dr = density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting. dL = density of cargo at the loading temperature and pressure.
(b) Nonrefrigerated tanks shall be filled so that their filling densities shall not exceed the ratios indicated in table 38.15-1(b).
(c) The “filling density” is defined as the percent ratio of the weight of the gas in a tank to the weight of water the tank will hold at 60 °F.
Table 38.15-1(b) - Maximum Permissible Filling Densities for Tanks Operating At or Near Ambient Temperature
at 60 °F.
|Maximum permitted filling density|
|Unlagged tanks - water capacity||Lagged tanks - all capacities|
|1,200 gal. and under||Over 1,200 gal.|
Note: Increase in filling densities to provide for seasonal changes may be considered by the Commandant upon presentation of factual evidence that safe operation can be effected.