ORDINANCE NO. 8874 - Laserfiche WebLink

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423 TABLE 3 UNDERGROUND STORAGE TANKS 1~4INIA.NM THICKNESS OF ~1ATERIAL Capacity Gauge Pounds Per (Gallons) (IJ.S. Standard ) Square Foot 1 to 285 lb 16 2.50 286 to 560 14 3.125 561 to 1,100 12 4.375 1,101 to 4,000 7 7.50 L~.,001 to 12,000 1~4 - inch 10.00 12,001 to 20,000 5/16 - inch 12.50 20,001 to 30,000 3~8 -inch 15.00 Tanks of steel or wrought iron thinnex than No. 7 gauge shall be galvanized. For Class III liquids, if adequate internal bracing is provided from 12,001 to 30,0®0 gallons capacity may be built of steel plate ~ - inch thick. With the approval of the Chief of the Bureau of Fire Pre vention, tanks of copper or other suitable materials may be used if after the necessary handling incident to installation they are equivalent in strength, rigidity, durability and tightness to the steel or iron tanks described above. 957. iv7ATERIAL OF A30VE GROUND TANKS. Tanks (including tops) shall be constructed throughout of open hearth steel or of wrought iron of a thickness in accordance with the following requirements. For liquids of 35° A.P.I. or heavier, tanks may be constructed of concrete in accordance with Standards of the National Roard of Fire Underwriters. (a) HORIZONTAL OR VERTICAL TANKS NOT OVER 1,100 GALLON CAPACITY. Capacity (gallons) y 1 to 60 61 to 350 351 to 56U 561 to 1,100 N!inimum Thicknes s of Materi«1 18 Gauge (U.S. Std.) 16 14 r, :: 12 „ " (b) VERTICAL TAPIKS OVER 1,100 GALLONS CAPACITY. Tanlcs of this class shall be of such material and so constructed as to have a factor of safety of at least 2.5. The minimum thickrness of shell or bottom shall be 316 - inch. The minimum thickness of roof shall be 1~8 - inch. The thickness of plates shall be in accordance with the following formula: t= 2.60I~x HxDxF T x E Where, " Thickness of plate in inches. H •'° height of tank in feet aoove the bottom of the ring undor consideration. D ' D~:ameter of the tank in feet. F " fi~'actor of safety (taken as 2.5) T "' Tensile strength of plate in pounds per square inch. • E `° efficiency of vertical joint in ring under consideration. The tensile strength of the steel shall be taken as 55,000 pounds per square inch, and the•shearing strength ci^ rivets ahall be taken as 1F0,000 pounds per square inch. Roofs orfi~ps of tanks shall have no unprotected openings. Roofs or tops shall be firmly and permanently joined to the tank and all joints shall be rivited and caulked, brazed, welded or made tight by other process satisfactory to the Chief of the Bureau of Fire Preventian. With the approval of the Chief of the Bureau of Fire Prevention tanks of copper or other suitable material or tanks of a special tested design may be used if after the necessary handling incident to installation, they are equivalent in strength, rigidity, durability and tightness to the steel or iron tanks described above.