{"data":{"id":"us/49-cfr-179.400-7","jurisdiction":"us","citation":"49 CFR 179.400-7","heading":"-7 Tank heads.","body":"(a) Tank heads of the inner tank and outer jacket must be flanged and dished, or ellipsoidal.\n(b) Flanged and dished heads must have—\n(1) A main inside dish radius not greater than the outside diameter of the straight flange;\n(2) An inside knuckle radius of not less than 6 percent of the outside diameter of the straight flange; and\n(3) An inside knuckle radius of at least three times the head thickness.","path":["Title 49—Transportation","Subtitle B—Other Regulations Relating to Transportation","CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION","SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS","PART 179—SPECIFICATIONS FOR TANK CARS","Subpart F—Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A)"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-49.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:26:34Z","sha256":"1903119a05b3a3317b7ce07d641a153803125da2822512f53fb09bb627a372a4","source_id":"us-cfr","stale":true,"prev":"us/49-cfr-179.400-6","next":"us/49-cfr-179.400-8"},"notice":"GroundRules: Original legal text. Not legal advice."}