ASTM A106 covers seamless carbon steel pipe designed for high-temperature service, ranging from NPS 1/8 to NPS 48 with nominal wall thicknesses defined by ASME B36.10M. This specification allows for variations in pipe dimensions, as long as they meet all other specification requirements. ASTM A106 pipes are suitable for bending, flanging, and welding, and the appropriate welding procedures must be used based on the steel grade and intended service.
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Common applications for ASTM A106 include high-temperature pressure piping for water, air, steam, and other fluids. While it is categorized for high-temperature use, it is approved for low-temperature service down to -20°F (-29°C), though it is more commonly used in environments up to 800°F (427°C). However, its allowable stresses decrease significantly above 400°F (200°C).
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As a standard for seamless pipe manufacturing, A106 prohibits the use of welded pipe forms like ERW, HFIW, or DSAW. Unlike national codes such as API, ASME, or CSA, ASTM A106 is not often mandated by legal requirements, but it has been adopted by ASME for use in pressure vessel (BPVC) and pressure piping (B31.X) applications under the designation SA106. It's essential to note that minor differences may exist between the ASTM and ASME versions, often due to the lag between their respective approval cycles. Engineers frequently reference the latest ASTM version for stricter requirements.
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ASTM A106 specifies a minimum manganese content of 0.30%, though the typical range is higher, with hot-rolled products often containing 0.80% to 1.20% Mn. The Mn/C ratio typically ranges from 3 to 5, which leads to limitations in low-temperature applications. For temperatures approaching -20°F (-29°C), products like SA333 are often specified.
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ASTM A106 does not have its own dimension table but follows the ASME B36.10 standard for nominal pipe dimensions. A106 pipes are often multi-certified to meet ASTM A53, A333, and API 5L standards. For welding, SA106 is categorized in the P1G1 alloy group for Grade B, and P1G2 for Grade C, as defined by ASME BPVC Section IX.
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Although ASTM A106 Grade A exists, it is rarely stocked in North America, and engineers typically specify Grades B or C for higher strength requirements. Non-destructive testing (NDT) may replace hydrotesting, provided the NDT method used is capable of full-thickness inspection.
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Basic Properties:
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Grade A: Min. Yield Strength (YS): 30 ksi (205 MPa), Min. Ultimate Tensile Strength (UTS): 48 ksi (330 MPa), not impact tested.
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Grade B: Min. YS: 35 ksi (240 MPa), Min. UTS: 60 ksi (415 MPa), not impact tested.
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Grade C: Min. YS: 40 ksi (275 MPa), Min. UTS: 70 ksi (485 MPa), not impact tested.
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