46 C.F.R. § 153.964 Discharge by gas pressurization.
Title 46 - Shipping
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.
Title 46: Shipping
PART 153—SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS
Subpart C—Operations
Cargo Transfer Procedures
§ 153.964 Discharge by gas pressurization.
