This recommended practice has been prepared to address the need for high quality application of coatings to the interior surfaces of rail tank cars handling shipments of concentrated sulfuric acid at ambient temperatures. Qualified inspection of the completed coating system and testing by the use of adequate, readily available instruments are also covered in this recommended practice.

This recommended practice emphasizes that corrosion is a major factor that must be considered in the design of tank cars transporting concentrated sulfuric acid. In addition to adhering to the conditions set forth in this document, these tank cars must comply with U.S. Department of Transportation (DOT) Specification DOT 111 A 100W2 and Association of American Railroads (MR) standards, and minimum as-built wall thicknesses should be 11 mm (0.435 in.). This document is not meant to provide a full treatise on corrosion of steel by concentrated sulfuric acid; this is an extensive subject in its own right and for further information the reader is referred to data published by NACE and other sources.

This NACE standard was developed by Task Group T-14C-1, a component of Unit Committee T-14C on Rail Equipment Corrosion, and is issued by NACE 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 railroad steel tank cars used primarily in the transportation of concentrated (90 to 98%) sulfuric acid at ambient temperatures.

For the purpose of this standard, concentrated H2SO4 is considered to be 90 to 98%.

Historical Document 1992