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life of the pipeline to document the operating pressure limit of a section of pipe or to demonstrate compliance with integrity management requirements. 7.7.9 API Recommended Practice 579-1/ASME FFS-1, Fitness-for-Service, Part 3 This recommended practice 165 addresses "Assessment of Existing Equipment for Brittle Fracture" and provides guidelines for evaluating the resistance to brittle fracture of existing carbon and low alloy steel pressure vessels, piping, and storage tanks. If the results of the fitness-for-service assessment indicate that the AST is suitable for the current operating conditions,then the equipment can continue to be operated under the same conditions provided that suitable monitoring/inspection programs are established.API RP 579-1/ASME FFS-1 is intended to supplement and augment the requirements in API 653.That is, when API 653 does not provide specific evaluation procedures or acceptance criteria for a specific type of degradation, or when API 653 explicitly allows the use of fitness-for-service criteria,API RP 579-1/ASME FFS-1 may be used to evaluate the various types of degradation or test requirements addressed in API 653. A brittle fracture assessment may be warranted based on operating conditions and/or the condition of the AST.API RP 579-1/ASME FFS-1 provides separate brittle fracture assessment procedures for continued service based on three levels.All three apply to pressure vessels, piping, and tankage, although a separate assessment procedure is provided for tankage. • Level 1 assessments are used for equipment that meets toughness requirements in a recognized code or standard (e.g., API 650). • Level 2 assessments exempt equipment from further assessment and qualify it for continued service based on one of three methods that utilize operating pressure and temperature; performance of a hydrotest; or the materials of construction, operating conditions, service environment, and past operating experience. • Level 3 assessments,which normally utilize a fracture mechanics methodology, are used for tanks that do not meet the acceptance criteria for Levels 1 and 2. A decision tree in API RP 579-1/ASME FFS-1 (Figure 3.3, Brittle Fracture Assessment for Storage Tanks) outlines this assessment procedure.The Level 1 and Level 2 brittle fracture assessment procedures are nearly identical to those found in API 653, Section 5,with a few notable exceptions: API 653 does not use the Level 1 and Level 2 designations;API 653 applies only to tanks that meet API 650 (7th edition or later) construction standards,whereas API 579-1/ASME FFS-1 applies to tanks that meet toughness requirements in the "current construction code;" and the two standards set a different limit on the maximum membrane stress (the stress forces that form within the shell as a result of the pressure of the liquid inside the vessel).There is, however, one major difference between API 653 and API 579-1/ASME FFS-1:API 653 Section 5 does not allow for an exemption of the hydrostatic test requirement whereas API 579-1/ASME FFS-1 does.API 579-1/ASME FFS-1 165 API Recommended Practice 579,"Fitness for Service,"2nd Edition,American Petroleum Institute,June 2007. SPCC GUIDANCE FOR REGIONAL INSPECTORS 7-73 December 16, 2013