[Code of Federal Regulations]
[Title 49, Volume 2]
[Revised as of October 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 49CFR179.400-7]

[Page 1100]
 
                        TITLE 49--TRANSPORTATION
 
   CHAPTER I--PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, 
                      DEPARTMENT OF TRANSPORTATION
 
PART 179_SPECIFICATIONS FOR TANK CARS--Table of Contents
 
Subpart F_Specification for Cryogenic Liquid Tank Car Tanks and Seamless 
                 Steel Tanks (Classes DOT-113 and 107A)
 
Sec.  179.400-7  Tank heads.

    (a) Tank heads of the inner tank and outer jacket must be flanged 
and dished, or ellipsoidal.
    (b) Flanged and dished heads must have--
    (1) A main inside dish radius not greater than the outside diameter 
of the straight flange;
    (2) An inside knuckle radius of not less than 6 percent of the 
outside diameter of the straight flange; and
    (3) An inside knuckle radius of at least three times the head 
thickness.