API STD 6X-2019 pdf free download

API STD 6X-2019 pdf free download.Design Calculations for Pressure-containing Equipment.
Scope 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 natural 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. Fatigue analysis is outside the scope of this document. Bolting allowable stresses are given in API product specifications and are outside the scope of this document. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies, except that new editions may be used on issue and shall become mandatory upon the effective date specified by the publisher or 1 2 months from the date of the revision (where no effective date is specified). API Specification 6A, Specification for Wellhead and Tree Equipment 3 Terms, Definitions, and Symbols 3.1 Terms and Definitions For the purpose of this document the following terms and definitions apply. 3.1.1 elastic analysis Method of structural analysis based on the assumption that the material has a linear elastic stress-strain relationship and therefore does not account for yielding or plastic behavior. 3.1.2 extreme conditions Conditions due to specified events such as seismic loading, wind loading, and wave loading in which loading is additive to the normal loading at operating conditions. See 5.3.2.3. 3.1.3 gross distortion Distortion to the extent that the product no longer functions as intended.
4 Failure Modes 4.1 Application NOTE A design analysis methodology and requirements are provided in this document for protection against the failure modes listed below. The methodology assumes ductile metallic material behavior and has no provision for material defects. Other failure modes, such as bearing stress, buckling, brittle fracture, and fatigue may be applicable, but are outside the scope of this document. Products shall be evaluated for each applicable failure mode. If multiple assessment procedures are provided for a failure mode, use of only one of these procedures shall be required to qualify the design of a product. The impact of the effect of temperature on the mechanical properties of the material shall be determined if the rated temperature exceeds 250 °F (1 21 °C). NOTE API 6A provides guidance for testing of materials at elevated temperature and designing with the data so obtained. API TR 6MET and the reference sources listed in API 6A also provide guidance. The effect of thermal expansion on the clearances and interferences between parts may also be considered. 4.2 Protection Against Plastic Collapse Protection against plastic collapse shall be demonstrated by elastic analysis (5.3.2.1 , 5.3.2.2, and 5.3.2.3), limit analysis (7.2), or plastic analysis (7.3). NOTE Specific requirements for the hydrostatic test case are given for elastic analysis (5.3.2.1, item (a) and 6.2) and limit analysis (7.2). 4.3 Protection Against Local Failure Protection against local failure shall be demonstrated by elastic analysis (5.3.2.4) or plastic analysis (7.3). 4.4 Protection Against Ratcheting and Progressive Distortion Protection against ratcheting and progressive distortion shall be demonstrated by elastic analysis (5.3.2.1 , item (b); 5.3.3; and 6.3) or plastic analysis (7.4). 4.5 Pure Shear Protection against failure by pure shear shall be demonstrated by the methods in 6.2.
4.6 Serviceability Criteria Serviceability criteria that ensure the performance and functionality of the product, as defined by the manufacturer, shall be satisfied at critical locations when subjected to the operating and hydrostatic test conditions. NOTE Examples of serviceability criteria are limits on deflections or rotations that may cause leakage or operational concerns. 5 Elastic Analysis 5.1 Stress Limits 5.1.1 General For elastic analysis, stress components shall be calculated, combined, and then compared to limits for each category of stress based on multiples of the design stress intensity, S m , for the material in use and for the category of stress. For API 6A equipment, standard and non-standard materials shall be as defined in API 6A and the corresponding design stress intensity per 5.1 .2 or 5.1 .3 shall be used. For other equipment, the design stress intensity per 5.1 .2 shall be used, unless otherwise required by the product specification or manufacturer’s specification.