API RP 545, First Edition, Recommended Practice for Lightning Protection of Aboveground Storage Tanks for Flammable or Combustible Liquids, replaces the requirements of API 2003 regarding lightning protection for preventing fires in storage tanks with flammable or combustible contents. This recommended practice (RP) provides guidance and information to assist owners/operators with lightning protection for tanks. This RP does not provide complete protection for all possible lightning stroke occurrences. Applicability This RP is applicable to tanks as described in API 650. Application of Requirements to New and Existing Tanks The requirements of this RP shall apply to new or reconstructed tanks. The requirements may be applied to existing tanks at the discretion of the owner/operator.