49 C.F.R. § 179.400-10 Sump or siphon bowl.
Title 49 - Transportation
A sump or siphon bowl may be in the bottom of the inner tank shell if— (a) It is formed directly into the inner tank shell, or is formed and welded to the inner tank shell and is of weldable quality metal that is compatible with the inner tank shell; (b) The stress in any orientation under any condition does not exceed the circumferential stress in the inner tank shell; and (c) The wall thickness is not less than that specified in §179.401–1.
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)
§ 179.400-10 Sump or siphon bowl.
