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UL 2245 Standard for Safety Below-Grade Vaults

UL 2245 standards cover below-grade vaults intended for the storage of flammable or combustible liquids in an aboveground atmospheric tank. Below-grade vaults are designed to contain one aboveground tank which can be a compartment tank. Adjacent vaults may share a common wall. The lid of the vault may be at or below-grade.

Below-grade vaults should be constructed of a minimum of 6 inches (152.4 mm) of reinforced concrete or other equivalent noncombustible material and form a complete, liquid-tight enclosure that does not allow external ground water to permeate through the vault walls. Below-grade vaults can be evaluated as secondary containment vaults.

Below-grade vaults covered by these requirements do not include an evaluation of components, such as ventilation equipment, leak detection and monitoring equipment, overfill protection equipment, and access ladders.

Below-grade vaults are intended for installation and use in accordance with the manufacturer’s instructions and the following fire codes: the Flammable and Combustible Liquids Code, NFPA 30, the Automotive and Marine Service Station Code, NFPA 30A, and the Uniform Fire Code, Appendix II-J.

Below-grade vaults covered by these requirements may be shipped in parts that require final assembly in the field. When field assembly is required, detailed installation instructions shall be provided.