46 CFR § 38.15-1 - Filling of tanks—TB/ALL.
---
identifier: "/us/cfr/t46/s38.15-1"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 38.15-1 - Filling of tanks—TB/ALL."
title_number: 46
title_name: "Shipping"
section_number: "38.15-1"
section_name: "Filling of tanks—TB/ALL."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "D"
subchapter_name: "TANK VESSELS"
part_number: "38"
part_name: "LIQUEFIED FLAMMABLE GASES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 2103, 3306, 3703; 49 U.S.C. 5101, 5106; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGFR 66-33, 31 FR 15269, Dec. 6, 1966, unless otherwise noted."
cfr_part: "38"
---
# 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:
*V*<sub>L</sub> = 0.98*d*<sub>r</sub> *V/d*<sub>L</sub>
where:
*V*<sub>L</sub> = maximum volume to which tank may be loaded.
*V* = volume of tank.
*d*<sub>r</sub> = density of cargo at the temperature required for a cargo vapor pressure equal to the relief valve setting.
*d*<sub>L</sub> = 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
| | | | |
| --- | --- | --- | --- |
| 0.473-0.480 | 38 | 41 | 42 |
| 0.481-0.488 | 39 | 42 | 43 |
| 0.489-0.495 | 40 | 43 | 44 |
| 0.496-0.503 | 41 | 44 | 45 |
| 0.504-0.510 | 42 | 45 | 46 |
| 0.511-0.519 | 43 | 46 | 47 |
| 0.520-0.527 | 44 | 47 | 48 |
| 0.528-0.536 | 45 | 48 | 49 |
| 0.537-0.544 | 46 | 49 | 50 |
| 0.545-0.552 | 47 | 50 | 51 |
| 0.553-0.560 | 48 | 51 | 52 |
| 0.561-0.568 | 49 | 52 | 53 |
| 0.569-0.576 | 50 | 53 | 54 |
| 0.577-0.584 | 51 | 54 | 55 |
| 0.585-0.592 | 52 | 55 | 56 |
| 0.593-0.600 | 53 | 56 | 57 |
| 0.601-0.608 | 54 | 57 | 58 |
| 0.609-0.617 | 55 | 58 | 59 |
| 0.618-0.626 | 56 | 59 | 60 |
| 0.627-0.634 | 57 | 60 | 61 |
| 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. | | | |