American Petroleum Institute

Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants - FOURTH EDITION; ERTA: November 1992
 N PUBL 941

Annotation

This publication applies to equipment in petroleum refineries and petrochemical plants in which hydrogen or hydrogen-containing fluids are processed, stored, loaded and unloaded, or otherwise handled.

Many processing facilities contain specialized equipment within which liquids or vapors are continuously processed in contact with hydrogen at elevated temperatures and pressures. In some cases, the equipment operates under conditions in which both chemical and physical changes occur in carbon steel, making it unsuitable for safe operation. Alloy steels can be used under these conditions, but there is an economic incentive to use the lowest alloy steel that is satisfactory. This publication summarizes the results of experimental tests and data acquired from operating plants in which practical operating limits have been established for carbon and alloy steels. Additional effects that result from cold working or heat treating are also discussed.

Hydrogenation processes, together with considerations of operating continuity, dictate standards or materials that may not be warranted in other operations of the petroleum industry. Although these recommendations have been prepared for refinery equipment, it is recognized that a modern refinery includes facilities other than those traditionally associated with refining operations. Petrochemical and chemical facilities are often interrelated with refining equipment both physically and by process procedure. The practices recommended in this publication can be applied to these additional facilities to the extent that such physical relationships or similarities in conditions exist. These practices can also be applied to hydrogenation plants that are not connected with refineries; the most common plants are those that manufacture ammonia, methanol, edible oils, and higher alcohols.