API RP 545 pdf download Recommended Practice for Lightning Protection of Aboveground Storage Tanks for Flammable or Combustible Liquids 4Protection of Specific Types of Tanks 4.1Fixed-roof Tanks (Metallic) and Tanks with Internal Floating Roofs For fixed roof tanks (metallic cone or dome) and internal floating-roof tanks (IFRTs), there is a possibility of flammablevapors being present at atmospheric vents. If present,flammable...