Current through Register Vol. 54, No.43, October 26, 2024
Section 14a.7 - Design, construction and use of tanks(a)General. Tanks shall be designed and constructed to safely withstand the service to which they are subjected. Use of a tank vehicle or railroad tank car, not meeting the requirements of this section, for purposes other than its designed use such as a storage or supply tank, is prohibited.(b)Materials and fabrication. The materials and fabrication of tanks shall conform to the following:(1) Tanks shall be built of steel unless the character of liquids stored requires some other material. Tanks built of materials other than steel shall be designed to specifications embodying principles recognized as good engineering design for the material used. Unlined concrete tanks may be used for storing flammable or combustible liquids having a gravity of 40°API or heavier. Concrete tanks with special lining may be used for other services if the design is in accordance with sound engineering practice. Tanks may have combustible or noncombustible linings. Special engineering considerations are required if the specific gravity of the liquid to be stored exceeds that of water or if the tanks are designed to contain flammable or combustible liquids at a liquid temperature below 0°F.(2) Tanks may be of any shape or type consistent with sound engineering design. Metal tanks shall be welded, riveted and caulked, brazed, or bolted, or constructed by use of a combination of these methods. Filler metal used in brazing shall be nonferrous metal or an alloy having a melting point above 1000°F. and below that of the metal joined.(c)Atmospheric tanks. The following contain the minimum requirements for construction of steel atmospheric tanks: (1) Underwriters' Laboratories, Incorporated, Subject No. 142-1981, Standard for Steel Aboveground Tanks for Flammable and Combustible Liquids.(2) American Petroleum Institute Standard No. 650-1980, Welded Steel Tanks for Oil Storage.(3) American Petroleum Institute Standards No. 12B-1977, Specification for Bolted Tanks for Storage of Production Liquids; No. 12MD-1982, Specification for Field Welded Tanks for Storage of Production Liquids; or No. 12F-1982, Specification for Shop Welded Tanks for Storage of Production Liquids. Tanks built in accordance with these standards shall be used only as production tanks for storage of crude petroleum in oil producing areas.(4) Skid tanks and similar portable equipment of 61 to 660 gallons capacity shall be of single compartment design and constructed in accordance with accepted engineering practice. Joints shall be welded.(i) Tank heads over 6 feet in diameter shall be dished, stayed, braced or reinforced.(ii) Minimum thickness shall be in accordance with the following: | Capacity Gallons | Minimum Thickness of Steel Mfrs. Gauge no. |
| 61-275 | 14 |
| 276-550 | 12 |
| 551-660 | 10 |
(iii) A fill opening shall be provided and shall be equipped with a closure design, so that it may be locked. The fill opening shall be separate from the vent opening.(iv) Tanks not mounted on runners or resting on metal legs shall be mounted in a stable position on noncombustible blocks approximately 6 inches in height, so as to protect the bottom of the tank from corrosion.(5) Skid tanks and similar portable equipment of 661 to 2,000 gallons capacity shall be constructed in accordance with the standards contained in the publications referenced in subsection 5(c)(1) and (2).(d)Low pressure tanks. The following contain the minimum requirements for construction of steel low pressure tanks:(1) American Petroleum Institute Standard No. 620-1982, Recommended Rules for the Design and Construction of Large, Welded Low-Pressure Storage Tanks.(2) The normal operating pressure of the tank shall not exceed the design pressure of the tank.(3) Atmospheric tanks built according to Underwriters' Laboratories, Incorporated, Subject No. 142-1981 may be used for operating pressures not exceeding one psig and shall be limited to 21/2 psig under emergency venting conditions.The provisions of this § 13.7 amended June 22, 1984, effective 6/18/1984, 14 Pa.B. 2131; transferred from 37 Pa. Code and renumbered as 34 Pa. Code §14a.7, February 28, 2014, effective 3/1/2014, 44 Pa.B. 1233. This section cited in 34 Pa. Code § 14a.111 (relating to storage and handling); 34 Pa. Code § 14a.141 (relating to scope and application); 34 Pa. Code § 14a.151 (relating to scope and application); and 34 Pa. Code § 14a.161 (relating to general provisions).