Regulationhistorical
49 CFR 179.400-7
Tank heads.
Snapshot 2005-10-01 Government source
eCFR editorial compilationAuthoritative but unofficial
View source (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.