Standard 612 specifies requirements and gives recommendations for the design, materials, fabrication, inspection, testing and preparation for shipment of steam turbines for special-purpose applications. It also covers the related lube-oil systems, instrumentation, control systems and auxiliary equipment. It is not applicable to general-purpose steam turbines, which are covered in API 611 (ISO 10436).

This edition of API Std 612 is the identical national adoption of ISO 10437, Petroleum, petrochemical and natural gas industries-Steam turbines-Special-purpose applications.