This standard practice has been prepared for the rail tank car industry to address the need for high-quality application of coatings to the interior surfaces of rail tank cars carrying a variety of chemicals at various temperatures. Qualified inspection of the completed coating system and testing with the use of adequate, readily available instruments also are covered.
Coating manufacturers, coating applicators, and those who have contracting authority for rail tank car internal coating instllation should be able to use this standard to ascertain the procedures, facilities, equipment, and personnel needed to satisfy the requirements for coating systems for rail tank cars in chemical service.
A large number of commercial 93 to 98% sulfuric acid (H2SO4) shipments in the United States and Canada are transported by rail in carbon steel tank cars. Concentrated sulfuric acid (93-98%) is an oxidizing agent and a desiccant. The major problems in its handling and storage relate to its hygroscopic nature (absorption of atmospheric humidity), its exothermic reactivity with water on dilution, and velocity effects that erode the otherwise protective films of corrosion products.
This standard is intended for use by tank car owners, coating systems suppliers, and coating system applicators for the auditing of the facilities, equipment, and personnel that satisfy the requirements for tank car coating systems in sulfuric acid service.