46 CFR § 154.405 - Design vapor pressure (P) of a cargo tank.
---
identifier: "/us/cfr/t46/s154.405"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "46 CFR § 154.405 - Design vapor pressure (P) of a cargo tank."
title_number: 46
title_name: "Shipping"
section_number: "154.405"
section_name: "Design vapor pressure (P) of a cargo tank."
chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"
subchapter_number: "O"
subchapter_name: "CERTAIN BULK DANGEROUS CARGOES"
part_number: "154"
part_name: "SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "46 U.S.C. 3703, 9101; Department of Homeland Security Delegation No. 0170.1."
regulatory_source: "CGD 74-289, 44 FR 26009, May 3, 1979, unless otherwise noted."
cfr_part: "154"
---
# 154.405 Design vapor pressure (P) of a cargo tank.
(a) The design vapor pressure (P<sub>o</sub>) of a cargo tank must be equal to or greater than the MARVS.
(b) The P<sub>o</sub> of a cargo tank must be equal to or greater than the vapor pressure of the cargo at 45 °C (113 °F) if:
(1) The cargo tank has no temperature control for the cargo; and
(2) The vapor pressure of the cargo results solely from ambient temperature.
(c) The P<sub>o</sub> of a cargo tank may be exceeded under harbor conditions if specially approved by the Commandant (CG-ENG).
[CGD 74-289, 44 FR 26009, May 3, 1979, as amended by CGD 82-063b, 48 FR 4782, Feb. 3, 1983]