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Unformatted text preview: Designation: A 250/A 250M – 95 An American National Standard Standard Specification for Electric-Resistance-Welded Ferritic Alloy-Steel Boiler and Superheater Tubes 1 This standard is issued under the fixed designation A 250/A 250M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon ( e ) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This specification 2 covers several grades, designated T1, T1a, T1b, T2, T11, T12 and T22, of minimum-wall-thickness, electric-resistance-welded, carbon-molybdenum and chromium-molybdenum alloy-steel, boiler and superheater tubes. 1.2 The tubing sizes and thicknesses usually furnished to this specification are 1 / 2 to 5 in. [12.7 to 127 mm] in outside diameter and 0.035 to 0.320 in. [0.9 to 8.1 mm], inclusive, in minimum wall thickness. Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of this specification. 1.3 Mechanical property requirements do not apply to tubing smaller than 1 / 8 in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness. 1.4 An optional supplementary requirement is provided and, when desired, shall be so stated in the order. 1.5 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specifi- cation. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order. 2. Referenced Documents 2.1 ASTM Standards: A 450/A 450M Specification for General Requirements for Carbon, Ferritic Alloy, and Austenitic Alloy Steel Tubes 3 E 213 Practice for Ultrasonic Examination of Metal Pipe and Tubing 4 E 273 Practice for Ultrasonic Examination of Longitudinal Welded Pipe and Tubing 4 3. Ordering Information 3.1 Orders for material under this specification should include the following, as required, to describe the desired material adequately: 3.1.1 Quantity (feet, metres, or number of lengths), 3.1.2 Name of material (electric-resistance-welded tubes), 3.1.3 Grade (Table 1), 3.1.4 Size (outside diameter or minimum wall thickness), 3.1.5 Length (specific or random), 3.1.6 Optional requirement (11.6), 3.1.7 Test report required (see Certification Section of Specification A 450/A 450M), 3.1.8 Specification designation, and 3.1.9 Special requirements and any supplementary require- ments selected....
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This note was uploaded on 02/01/2012 for the course CIVL 2770 taught by Professor Fariborz during the Winter '11 term at Manitoba.
- Winter '11