API SPEC 20A-2017 pdf download.Carbon Steel, Alloy Steel, Stainless Steel, and Nickel Base Alloy Castings for Use in the Petroleum and Natural Gas Industry.
1 Scope This specification identifies requirements for the foundry qualification, production, design, marking and documentation of carbon steel, alloy steel, stainless steel, and nickel-base alloy castings used in the petroleum and natural gas industries when referenced by an applicable API product standard or otherwise specified as a requirement for compliance. This specification applies to castings used in the manufacture of pressure containing, pressure-controlling, and primary load-bearing components. Castings manufactured in accordance with this API Standard may be produced using any industry standard casting method. This specification provides manufacturers with a fixed methodology to examine a qualification casting and to compare the results of that examination to a defined set of acceptance criteria. The results of the qualification testing by material grouping are then used to establish a baseline Casting Specification Level (CSL) for subsequently produced castings. This specification also provides manufacturers with a fixed production testing methodology to determine if subsequently produced castings conform to the minimum requirements for the intended CSL. The intent is that the production castings meet the minimum CSL requirements established during qualification testing by material grouping and/or the minimum CSL specified by the purchaser. If product is supplied bearing the API Monogram and manufactured at a facility licensed by API, the requirements of Annex A apply. 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 six months from the date of the revision (where no effective date is specified).
ASTM A703, Standard Specification for Steel Castings, General Requirements, for Pressure-Containing Parts ASTM E8, Standard Test Methods for Tension Testing of Metallic Materials ASTM E1 0, Standard Test Method for Brinell Hardness of Metallic Materials ASTM E1 8, Standard Test Methods for Rockwell Hardness of Metallic Materials ASTM E23, Standard Test Methods for Notched Bar Impact Testing of Metallic Materials ASTM E94, Standard Guide for Radiographic Examination ASTM E1 1 0, Standard Test Method for Indentation Hardness of Metallic Materials by Portable Hardness Testers ASTM E1 1 2, Standard Test Methods for Determining Average Grain Size ASTM E1 65, Standard Practice for Liquid Penetrant Examination for General Industry ASTM E1 86, Standard Reference Radiographs for Heavy-Walled (2 to 4 1 / 2 -in. (50.8 to 114-mm)) Steel Castings ASTM E280, Standard Reference Radiographs for Heavy-Walled (4 1 / 2 to 12-in. (114 to 305-mm)) Steel Castings ASTM E340, Standard Test Method for Macroetching Metals and Alloys ASTM E428, Standard Practice for Fabrication and Control of Metal, Other than Aluminum, Reference Blocks Used in Ultrasonic Testing ASTM E446, Standard Reference Radiographs for Steel Castings Up to 2 in. (50.8 mm) in Thickness ASTM E562, Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count ASTM E709, Standard Guide for Magnetic Particle Testing ASTM E747, Standard Practice for Design, Manufacture and Material Grouping Classification of Wire Image Quality Indicators (IQI) Used for Radiology
3.1.4 carbon steel Alloy of carbon and iron containing a maximum of 2 % mass fraction carbon, 1 .65 % mass fraction manganese, and residual quantities of other elements, except those intentionally added in specific quantities for deoxidation (usually silicon and/or aluminum). 3.1.5 casting practice General method for producing a casting. NOTE This includes the molding practice. Examples of molding practice include, but are not limited to, sand, centrifugal, investment, shell, permanent mold, die or lost foam casting. 3.1.6 corrosion-resistant alloy (CRA) Nonferrous-based alloy in which, any one or the sum of the specified amount of the elements titanium, nickel, cobalt, chromium, and molybdenum exceeds 50 % mass fraction. NOTE 1 . This definition is different from that in NACE MR01 75/ISO 1 51 56 (see Clause 2). NOTE 2. This definition is the same as that in API Spec 6A. 3.1.7 cosmetic grinding Grinding meant to remove small surface discontinuities but not to exceed minimum wall conditions and to be blended or feathered with the remaining surfaces. 3.1.8 duplex stainless steel Stainless steels with a high chromium mass fraction (1 9 % to 33 %) with or without molybdenum additions up to 5 %, and a nickel mass fraction intermediate to those of ferritic and austenitic stainless steels. NOTE Other elements may be added to secure special properties. 3.1.9 equivalent round Standard for comparing various shaped sections to round bars, in determining the response to hardening characteristics when heat-treating low-alloy and martensitic corrosion-resistant steel. 3.1.10 heat Material originating from a final melt or from re-melted alloys. The raw material originating from a single remelted ingot. NOTE Different heats of the same material can vary in chemical composition within prescribed limits. Stock from a single heat will have a consistent analysis and more uniform properties.