49 C.F.R. § 179.400-16 Access to inner tank.
Title 49 - Transportation
(a) The inner tank must be provided with a means of access having a minimum inside diameter of 16 inches. Reinforcement of the access opening must be made of the same material used in the inner tank. The access closure must be of an approved material and design. (b) If a welded closure is used, it must be designed to allow it to be reopened by grinding or chipping and to be closed again by rewelding, preferably without a need for new parts. A cutting torch may not be used.
Title 49: Transportation
PART 179—SPECIFICATIONS FOR TANK CARS
Subpart F—Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A)
§ 179.400-16 Access to inner tank.
