46 CFR § 153.964 - Discharge by gas pressurization.
---identifier: "/us/cfr/t46/s153.964"source: "ecfr"legal_status: "authoritative_unofficial"title: "46 CFR § 153.964 - Discharge by gas pressurization."title_number: 46title_name: "Shipping"section_number: "153.964"section_name: "Discharge by gas pressurization."chapter_name: "COAST GUARD, DEPARTMENT OF HOMELAND SECURITY"subchapter_number: "O"subchapter_name: "CERTAIN BULK DANGEROUS CARGOES"part_number: "153"part_name: "SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS"positive_law: falsecurrency: "2026-04-05"last_updated: "2026-04-05"format_version: "1.1.0"generator: "[email protected]"authority: "46 U.S.C. 3703; Department of Homeland Security Delegation No. 0170.1. Section 153.40 issued under 49 U.S.C. 5103. Sections 153.470 through 153.491, 153.1100 through 153.1132, and 153.1600 through 153.1608 also issued under 33 U.S.C. 1903 (b)."regulatory_source: "CGD 73-96, 42 FR 49027, Sept. 26, 1977, unless otherwise noted."cfr_part: "153"---
Identifier
/us/cfr/t46/s153.964
Currency
2026-04-05
Positive Law
No
Updated
2026-04-05
Chapter
Coast Guard, Department of Homeland Security
Authority
46 U.S.C. 3703; Department of Homeland Security Delegation No. 0170.1. Section 153.40 issued under 49 U.S.C. 5103. Sections 153.470 through 153.491, 153.1100 through 153.1132, and 153.1600 through 153... 46 U.S.C. 3703; Department of Homeland Security Delegation No. 0170.1. Section 153.40 issued under 49 U.S.C. 5103. Sections 153.470 through 153.491, 153.1100 through 153.1132, and 153.1600 through 153.1608 also issued under 33 U.S.C. 1903 (b).
# 153.964 Discharge by gas pressurization.The person in charge of cargo transfer may not authorize cargo discharge by gas pressurization unless:(a) The tank to be offloaded has an SR or PV venting system;(b) The pressurization medium is either the cargo vapor or a nonflammable, nontoxic gas inert to the cargo; and(c) The pressurizing line has:(1) A pressure reducing valve whose setting does not exceed 90% of the tank's relief valve setting and a manual control valve between the pressure reducing valve and the tank; or(2) For an inert gas medium:(i) A safety relief valve with a cross sectional flow area at least equal to that of the pressurizing line and whose relieving pressure does not exceed 90 percent of the tank's relief valve setting;(ii) A manual control valve between the safety relief valve and the tank; and(iii) A check valve between the manual control valve and the tank.