{"data":{"id":"us/33-cfr-183.516","jurisdiction":"us","citation":"33 CFR 183.516","heading":"Cellular plastic used to encase fuel tanks.","body":"(a) Cellular plastic used to encase metallic fuel tanks must:\n(1) Not change volume by more than five percent or dissolve after being immersed in any of the following liquids for 24 hours at 29 °C:\n(i) Reference fuel B ASTM D 471 (incorporated by reference, see § 183.5).\n(ii) No. 2 reference oil of ASTM D 471 (incorporated by reference, see § 183.5).\n(iii) Five percent solution of trisodium phosphate in water; and\n(2) Not absorb more than 0.12 pound of water per square foot of cut surface, measure under Military Specification MIL P-21929B.\n(b) Non-polyurethane cellular plastic used to encase metallic fuel tanks must have a compressive strength of at least 60 pounds per square inch at ten percent deflection measured under ASTM D 1621 (incorporated by reference, see § 183.5), “Compressive Strength of Rigid Cellular Plastics”.\n(c) Polyurethane cellular plastic used to encase metallic fuel tanks must have a density of at least 2.0 pounds per cubic foot, measured under ASTM D 1622 (incorporated by reference, see § 183.5), “Apparent Density of Rigid Cellular Plastics.”","path":["Title 33—Navigation and Navigable Waters","CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY","SUBCHAPTER S—BOATING SAFETY","PART 183—BOATS AND ASSOCIATED EQUIPMENT","Subpart J—Fuel Systems"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-33.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:35Z","sha256":"5e21b4e7c19da3eeff8b0c41fa4357f6025ad1fd549dccaead5051e722a96eb5","source_id":"us-cfr","stale":true,"prev":"us/33-cfr-183.514","next":"us/33-cfr-183.518"},"notice":"GroundRules: Original legal text. Not legal advice."}