153.964—Discharge by gas pressurization.
The person in charge of cargo transfer may not authorize cargo discharge by gas pressurization unless:
(b)
The pressurization medium is either the cargo vapor or a nonflammable, nontoxic gas inert to the cargo; and
(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
(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;