| Outside Diameter mm(in) | Body Tolerances mm(in) |
Ends Tolerances mm(in) |
Out -of-roundness tolerances | |
| Pipe except the end | Pipe end | |||
| < 60.3（2.375） | -0.8（0.031） to +0.4（ 0.016） | -0.8（0.031） to +0.4（ 0.017） | 1.2（0.048） | 0.9（0.036） |
| 60.3（2.375）to 168.3(6.625) | ±0.0075 D | -0.4 (0.016) to +1.6(0.063) | 0.020 D for D/t ≤ 75 |
0.015 D for D/t ≤ 75 |
| > 168.3(6.625) to 610(24.000) | ± 0.0075 D, but maximum of ± 3.2 (0.0125) |
± 0.005 D, but maximum of ± 1.6 (0.063) |
||
| Wall thickness | Tolerances |
| t mm(in) | mm(in) |
| t ≤ 5.0(0.197) | ± 0.5 (0.020) |
| > 5.0(0.197) to < 15.0(0.591) | ± 0.1t |
| t ≥ 15.0(0.591) | ± 1.5(0.060) |
| Hydrostatic testing | 100% of pipe shall be tested. Pipe must be able to survive a hydrostatic test without leaking through the weld seam or the pipe body |
| NDT | Weld seam of each pipe shall be tested by online Eddy Current test |
| Flattening Test（0 & 90 deg） | For Pipes over 2.875” i) No opening of the weld before the distance between the plates is less than 50% of the original outside diameter. ii) There shall be no crack or break other than in the weld before the distance between the plates is less than 33% of the original outside diameter. iii) No evidence of lamination or burnt metal shall develop during the flattening until opposite wall of the pipe meet. |
| Bend Test | There shall be no cracks in any part of the test piece, nor shall there be any opening of the weld. |
| Metallography | Micro Structure and Micro Hardness (HV10) test are carried out. |
| NPS | O. D. | Nominal Wall Thickness | |||||||||||||||
| DN | Inch | mm | SCH5S | SCH10S | SCH10 | SCH20 | SCH30 | SCH40 | SCH60 | SCH80 | SCH100 | SCH120 | SCH140 | SCH160 | STD | XS | XXS |
| 50 | 2″ | 60.3 | 1.65 | 2.77 | – | – | – | 3.91 | – | 5.54 | – | – | – | 8.74 | 3.91 | 5.54 | 11.07 |
| 65 | 2-1/2″ | 73 | 2.11 | 3.05 | – | – | – | 5.16 | – | 7.01 | – | – | – | 9.53 | 5.16 | 7.01 | 14.02 |
| 80 | 3″ | 88.9 | 2.11 | 3.05 | – | – | – | 5.49 | – | 7.62 | – | – | – | 11.13 | 5.49 | 7.52 | 15.24 |
| 90 | 3-1/2″ | 101.6 | 2.11 | 3.05 | – | – | – | 5.74 | – | 8.08 | – | – | – | – | 5.74 | 8.08 | – |
| 100 | 4″ | 114.3 | 2.11 | 3.05 | – | – | – | 6.02 | – | 8.58 | – | 11.13 | – | 13.49 | 6.02 | 8.56 | 17.12 |
| 125 | 5″ | 141.3 | 2.77 | 3.4 | – | – | – | 6.55 | – | 9.53 | – | 12.7 | – | 15.88 | 6.55 | 9.53 | 18.05 |
| 150 | 6″ | 168.3 | 2.77 | 3.4 | – | – | – | 7.11 | – | 10.97 | – | 14.27 | – | 18.26 | 7.11 | 10.97 | 21.95 |
| 200 | 8″ | 219.1 | 2.77 | 3.76 | – | 6.35 | 7.04 | 8.18 | 10.31 | 12.7 | 15.09 | 18.26 | 20.62 | 23.01 | 8.18 | 12.7 | 22.23 |
| 250 | 10″ | 273.1 | 3.4 | 4.19 | – | 6.35 | 7.8 | 9.27 | 12.7 | 15.09 | 18.26 | 21.44 | 25.4 | 28.58 | 9.27 | 12.7 | 25.4 |
| 300 | 12″ | 323.9 | 3.96 | 4.57 | – | 6.35 | 8.38 | 10.31 | 14.27 | 17.48 | 21.44 | 25.4 | 28.58 | 33.32 | 9.53 | 12.7 | 25.4 |
| 350 | 14″ | 355.5 | 3.96 | 4.78 | 6.35 | 7.92 | 9.53 | 11.13 | 15.09 | 19.05 | 23.83 | 27.79 | 31.75 | 35.71 | 9.53 | 12.7 | – |
| 400 | 16″ | 406.4 | 4.19 | 4.78 | 6.35 | 7.92 | 9.53 | 12.7 | 16.66 | 21.44 | 26.19 | 30.96 | 36.53 | 40.49 | 9.53 | 12.7 | – |
| 450 | 18″ | 457.2 | 4.19 | 4.78 | 6.35 | 7.92 | 11.13 | 14.27 | 19.05 | 23.83 | 39.36 | 34.93 | 39.67 | 45.24 | – | – | – |
| 500 | 20″ | 508 | 4.78 | 5.54 | 6.35 | 9.53 | 12.7 | 15.09 | 20.62 | 26.19 | 32.54 | 38.1 | 44.45 | 50.01 | – | – | – |
| 550 | 22″ | 558.8 | 4.78 | 5.54 | 6.35 | 9.53 | 12.7 | – | 22.23 | 28.58 | 34.93 | 41.28 | 47.63 | 53.98 | – | – | – |
| 600 | 24″ | 609.6 | 5.54 | 6.35 | 6.35 | 9.53 | 14.27 | 17.48 | 24.61 | 30.96 | 38.89 | 46.02 | 52.37 | 59.54 | – | – | – |
| Steel Grade | Chemical Composition | Mechanical Property | ||||||||||
| C (Max) | Mn (Max) | P (Max) | S (Max) | TENSILE ( Min ) | YIELD ( Min ) | |||||||
| Psi X 1000 | Mpa | Psi X 1000 | Mpa | |||||||||
| Grade A25 | CL I | 0.21 | 0.6 | 0.03 | 0.03 | 45 | 310 | 25 | 172 | |||
| CL II | 0.21 | 0.6 | 0.03 | 0.03 | ||||||||
| Grade A | 0.22 | 0.9 | 0.03 | 0.03 | 48 | 331 | 30 | 207 | ||||
| Grade B | 0.26 | 1.2 | 0.03 | 0.03 | 60 | 414 | 35 | 241 | ||||
| Grade X42 | 0.26 | 1.3 | 0.03 | 0.03 | 60 | 414 | 42 | 290 | ||||
| Grade X46 | 0.26 | 1.4 | 0.03 | 0.03 | 63 | 434 | 46 | 317 | ||||
| Grade X52 | 0.26 | 1.4 | 0.03 | 0.03 | 66 | 455 | 52 | 359 | ||||
| Grade X56 | 0.26 | 1.4 | 0.03 | 0.03 | 71 | 490 | 56 | 386 | ||||
| Grade X60 | 0.26 | 1.4 | 0.03 | 0.03 | 75 | 517 | 60 | 414 | ||||
| Grade X65 | 0.26 | 1.45 | 0.03 | 0.03 | 77 | 531 | 65 | 448 | ||||
| Grade X70 | 0.26 | 1.65 | 0.03 | 0.03 | 82 | 565 | 70 | 483 | ||||
| Steel Grade | Chemical Composition | Mechanical Property | ||||||||||
| C | Mn | P | S | Tensile | Yield | C. E. IMPACT ENERGY | ||||||
| Max | Max | Max | Max | Psi x 1000 | Mpa | Psi x 1000 | Mpa | PCM | IIW | J | FT/LB | |
| Grade B | 0.22 | 1.2 | 0.025 | 0.015 | 60 – 110 | 414 – 758 | 35 – 65 | 241 – 448 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X42 | 0.22 | 1.3 | 0.025 | 0.015 | 60 – 110 | 414 – 758 | 42 – 72 | 290 – 496 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X46 | 0.22 | 1.4 | 0.025 | 0.015 | 63 – 110 | 434 – 758 | 46 – 76 | 317 – 524 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X52 | 0.22 | 1.4 | 0.025 | 0.015 | 66 – 110 | 455 – 758 | 52 – 77 | 359 – 531 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X56 | 0.22 | 1.4 | 0.025 | 0.015 | 71 – 110 | 490 – 758 | 56 – 79 | 386 – 544 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X60 | 0.22 | 1.4 | 0.025 | 0.015 | 75 – 110 | 517 – 758 | 60 – 82 | 414 – 565 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X65 | 0.22 | 1.45 | 0.025 | 0.015 | 77 – 110 | 531 – 758 | 65 – 82 | 448 – 565 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X70 | 0.22 | 1.65 | 0.025 | 0.015 | 82 – 110 | 565 – 758 | 70 – 82 | 483 – 565 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Grade X80 | 0.22 | 1.9 | 0.025 | 0.015 | 90 – 120 | 621 – 827 | 80 – 102 | 552 – 705 | 0.25 | 0.43 | T/L 27/41 | T/L 20/30 |
| Main Advantage Of ERW Steel Pipes | - Low cost：the low raw material cost and manufacturing cost make it prices more competitive than longitudinal seam submerged-arc welded pipes and seamless pipes. - High Weld Seam Security：As a result of special welding method of melting parent metal together, without filler metal, the weld property is better than submerged-arc welded pipes; and the weld seam is much shorter than spiral seam welded pipes, the seam security is greatly improved. - Wide Range：ERW pipes can be applied with a wide range of thickness / diameter ratio, covering hundreds of specifications. |
| Difference between ERW, SSAW, LSAW | Steel pipe for pipe technology, can be divided into (SML), mainly as the Oilfield internal transportation pipeline and small-diameter high-pressure natural gas pipeline, used for a small number of long-distance gas pipeline, the vast majority of long-distance pipeline with Direct seam high frequency (ERW), spiral submerged arc (SSAW), LSAW three (LSAW). |
| Manual ultrasonic testing of ERW steel pipe welding joint | The residual defects in erw steel pipe ultrasonic testing is an important reason for failure of the weld, causing defects missed is inappropriate due to a probe parameter selection, disturbing wave effects and burr flaw echo echo does not distinguish between such a variety of factors. |
