This standard describes a design analysis methodology and requirements that apply to design verification of certain pressure-containing products and equipment in the oil and gas industry. The methods included in this document apply to designs where normative reference to this standard is made in an API product specification and to those components for which the methods of this standard are required or permitted.This standard is based on ASME Boiler and Pressure Vessel Code, Section VIII, Division 2, Appendix 4 (2004 edition with 2005 and 2006 addenda) but includes further limits established for oil and gas products as determined by API standardization committees. It includes closed-form solutions and methods for elastic analysis, elastic-plastic analysis, and guidance on finite element analysis methods. The methodology assumes ductile metallic material behavior and has no provision for material defects.Fatigue analysis is outside the scope of this document.