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API Spec 6A Tensile Test Spec Reference Requirements. Tim Haeberle API SC6 2012 Summer Meeting. Background. CURRENT WORDING 5.3.5.2 PSL 2 to 4 tensile testing (for mandrel tubing hangers and casing hangers) “b) test method:
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API Spec 6A Tensile Test Spec Reference Requirements Tim Haeberle API SC6 2012 Summer Meeting
Background CURRENT WORDING • 5.3.5.2 PSL 2 to 4 tensile testing (for mandrel tubing hangers and casing hangers) “b) test method: Perform tensile tests at room temperature in accordance with the procedures specified in ISO 6892-1or ASTM A370. Perform a minimum of one tensile test. The results of the tensile test(s) shall satisfy the manufacturer’s specified requirements.” • 5.4.2.3 PSL 2 to 4 tensile testing (for bodies, bonnets, and end and outlet connections) “b) test method: Perform tensile tests at room temperature in accordance with the procedures specified in ISO 6892-1or ASTM A370. Perform a minimum of one tensile test. The results of the tensile test(s) shall satisfy the applicable requirements of Table 6.”
Background CURRENT WORDING • Section 5.6.4.1 (for TC’s for PSL 1) Paragraph 5 - “Standard-sized, 12,5 mm (0,500 in) diameter tensile specimens shall be used to qualify carbon, low-alloy and stainless steels, unless the physical configuration of the TC prevents their use. In this case, the standard sub-size specimens referenced in ASTM A370 may be used. Either standard 12,7 mm (0,500 in) or standard sub-size specimens (see ASTM A370) may be used to qualify CRA materials.” • Section 5.7.4.1 (for QTC’s for PSL 2-4) Paragraph 6 - “Standard-sized, 12,5 mm (0,500 in) diameter tensile specimens shall be used, unless the physical configuration of the QTC prevents their use. In this case, the standard sub-size specimens referenced in ASTM A370 may be used.” PROBLEM: • These paragraphs do not state that the “standard” specimens are ASTM A370 standard-sized specimens. This leaves open the use of ISO 6892-1 standard specimens. Additionally, they refer to the “standard sub-size specimens”, but the correct term in ASTM A370 is “small-size specimens”.
The Solution PROPOSED REVISIONS: • Section 5.6.4.1 Paragraph 5 - “ASTM A370standard-sized, 12,5 mm (0,500 in) diameter tensile specimens shall be used to qualify carbon, low-alloy and stainless steels, unless the physical configuration of the TC prevents their use. In this case, the standard sub-size specimens referenced in ASTM A370 may be used. Either standard 12,5 mm (0,500 in) or standard sub-size specimens (see ASTM A370) may be used to qualify CRA materials.” • Section 5.7.4.1 Paragraph 6 - “ASTM A370standard-sized, 12,5 mm (0,500 in) diameter tensile specimens shall be used, unless the physical configuration of the QTC prevents their use. In this case, the standard sub-size specimens referenced in ASTM A370 may be used.”
The Solution JUSTIFICATION: • “ASTM A370” needs to be added to clarify that the only specimen sizes currently permitted are the ASTM A370 specimen sizes. • ISO 6892-1 includes different size specimens that have a higher gage length to diameter ratio. • The longer relative gage length of the ISO 6892-1 specimens can result in failure to meet the API 6A specified elongation acceptance criteria. • The use of ASTM A370 specimen sizes meets ISO 6892-1, since ISO 6892-1, section 6.1.1, paragraphs 7 and 8 state: “The dimensional tolerances of the test pieces shall be in accordance with the Annexes B to E (see 6.2).” Other test pieces such as those specified in relevant product standards or national standards may be used by agreement with the customer, e.g. ISO 3183 [1] (API 5L), ISO 11960 [2] (API 5CT), ASTM A370[6], ASTM E8M [7], DIN 50125 [10], IACS W2 [13], and JIS Z2201 [14]”. • ASTM A370 specimen sizes are routinely used in the US and Europe.
API Ballot • Ballot ready for SC6 to approve at the 2012 Summer Meeting for formal balloting