This standard recommended practice has been prepared for the rail car industry to address the need for high-quality application of coatings to the interior surfaces of rail tank cars handling a variety of chemicals at various temperatures. Qualified inspection of the completed coating system and testing by the use of adequate, readily available instruments are also covered.
This standard emphasizes that corrosion and product contamination are major factors that must be considered in the design of tank cars transporting liquid commodities. In addition to adhering to the conditions set forth in this standard, these tank cars must comply with U.S. Department of
Transportation<1l Code of Federal Regulations (CFR) Title 49, Part 179, 1 Transport Canada
CGSB 43-GP-147P Sub-Part 79, and Association of American Railroads13l Standard M1002.
This standard is not meant to provide a full treatise on corrosion of steel by chemicals, which is an extensive subject in its own right. For further information the reader is referred to data published by NACE International and other sources.
Although most coatings are applied to prevent shipped product from being contaminated by a corroding tank car, DOT and AAR are attempting to resolve the issue of how much corrosion should be allowed in tank cars. One factor to consider when adding a corrosion allowance is the required life of the tank car. The extra wall thickness of a tank car that is expected to be in service for 40 years can add substantially to the tank car's weight and result in a severe reduction in carrying capacity. In cars handling corrosive liquids, adding a corrosion allowance without any other form of corrosion protection is clearly not a practical solution for long-term operation.
This standard was developed by NACE International Task Group T-14C-6, a component of Unit
Committee T-14C on Rail Equipment Corrosion, and is issued by NACE International under the auspices of Group Committee T-14 on Corrosion in the Transportation Industry.
1.1 This standard describes a procedure for the application of a coating system to the interior surfaces of new and used rail tank cars that transport various liquid commodities.