Tank Farm Design Guidelines 416f2r

DRAFT ALASKA ENERGY AUTHORITY TANK FARM DESIGN GUIDELINES

1) The maximum storage capacity for a single tank farm shall be the DEC C-Plan threshold of 420,000 gallons. AEA may consider building two adjacent facilities that are each less than the C-plan threshold. 2) The IFC requires a 6’ fence around tank farms. The AEA standard is a 6’ fence with three strands of barbed wire on top of it. 3) In general, ball valves are preferred over gate valves due to the susceptibility of gate valves to failure from ice or debris accumulation. Gate valves may be preferable in fill line applications to limit the rate at which the valve can be shut (reducing the risk of hammer). 4) Solenoid valves are susceptible to failure from ice, debris and low pressure differential across the valve. If used, they should be protected by an upstream filter or strainer. 5) Spring-mounted manhole covers are not acceptable as emergency vents because someone may mistakenly tighten the bolts down. 6) Fill, distribution and manifold piping should be painted where feasible and affordable. 7) AEA will not provide facilities that allow the use of credit cards (i.e. card-swipe dispensers). Debit cards are acceptable. 8) Only one electrical meter will be provided at a tank farm. Additional meters may be included if paid for by others. 9) 30 micron filters should be specified for both diesel and gas sides of the dispenser. Smaller filter elements tend to plug up when the temperatures are very low. Six extra filters should be provided with each dispenser. 10)The IFC requires flame arrestors or pressure/vacuum vents on gasoline and protected above-ground tanks (3404.2.7.3.6 and 3404.2.9.6.3). AEA’s standard is to provide P/V whistle vents (such as the Morrison #922) on all bulk, intermediate and dispensing tanks. This satisfies the IFC requirement, reduces evaporative losses and water condensation, and meets the 2/25/02 Fire Marshal MOA #1 requirement #6. 11)Tank farm pole light fixtures shall be metal halide and controlled by photosensors where feasible to conserve energy. If temperatures lower than minus 40F are anticipated, the designer should consider specifying high pressure sodium fixtures that have lower strike temperatures than metal halide fixtures and comparable color rendering indices (i.e. CRI >= 70).

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12)BUNA seals should be specified for pumps and meters. 13)Electrical grounding rods should be copper. 14)If electrical control conduit runs are > 700’, consider specifying Remote Transmission Units (RTU). AEA has design samples and technical resources for this technology. 15)Flex connectors must be pressure-tested by the manufacturer to 110 psi for one hour and delivered with a pressure test certificate. In general, flex connectors should be at least 18” long. 16)Catwalks should be provided on all tanks that have submersible pumps. 17)Pipe wall-thickness specification should be based on site-specific conditions. However, in general pipe should be schedule 80 with the following exceptions: a) b) c) d)

Larger than 2” inside the dike may be schedule 40 Larger than 3” above grade and outside the dike may be schedule 40. 3” and smaller pipe should be at least schedule 80. 1” and smaller pipe that is subject to traffic or mechanical damage may be schedule 160 e) Buried pipe should be at least schedule 80 18)Each section of pipe that can be isolated by valves or other devices shall include a pressure relief valve. 19)On long distribution pipelines that have low points which could be subject to freezeup, install water blocking filters at the tank farm. The Cim-Tek General I filter (#40165) can be provided with 2” flanged connections and a 30 micron hydrosorb element and is good for up to 60 GPM. 20)On top-filled tanks which use a piped system connected to a fill limiting valve, install a flanged strainer with a 100 mesh screen immediately prior to the fill limiter.

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