(a) Tanks built under this specification shall be fusion-welded with heads designed convex outward. Except as provided in §179.103 they shall be circular in cross section, shall be provided with a manway nozzle on top of the tank of sufficient size to permit access to the interior, a manway cover to provide for the mounting of all valves, measuring and sampling devices, and a protective housing. Other openings in the tank are prohibited, except as provided in part 173 of this chapter, §§179.100-14, 179.101-1, 179.102 or §179.103.(b) Head shields and shells of tanks built under this specification must be normalized. Tank car heads must be normalized after forming unless specific approval is granted for a facility's equipment and controls.29 FR 18995, 12/29/1964. Redesignated at 32 FR 5606, 4/5/1967, and amended by Amdt. 179-10, 36 FR 21344, 11/6/1971; 65 FR 58632, 9/29/2000; 74 FR 1802, 1/13/2009