According to the 2007 edition of the American Petroleum Institute (API) 5L specification, API 5L X52 welded and seamless pipes should ensure that there are no defects such as cracks, folds, wrinkles, delamination, scars and scale on the inner and outer surfaces. During the removal process, it is required to ensure that the negative deviation of the nominal wall thickness and the actual thickness of the API 5L X52 PSL2 pipe meet the relevant standards and the grinding to remove surface defects should be a smooth transition, and welding methods should not be used to fill.
Specifically,
1. The inner and outer surfaces of the API 5L X52 PSL2 carbon steel pipe must be polished to a straight line, and the removal depth must not exceed the negative deviation of the nominal wall thickness.
2. The scale on the inner and outer surfaces of the API 5L X52 PSL2 steel pipeline should be removed, and the actual thickness of the removal area should not be less than the minimum wall thickness allowed by API 5L X52 PSL2.
3. In terms of pipe section shape, both ends of the API 5L X52 PSL2 steel pipe should be cut at right angles and burrs should be removed.
4. No welds are allowed on the API 5L X52 PSL2 pipeline.
API 5L X52 PSL2 High Strength Pipe Dimensional Tolerances OD, Out of Roundness and Wall Thickness
| Specified Outside Diameter D (in) | Diameter Tolerance, inches d | Out-of-Roundness Tolerance in | ||||
|---|---|---|---|---|---|---|
| Pipe except the end a | Pipe end a,b,c | Pipe except the End a | Pipe End a,b,c | |||
| SMLS Pipe | Welded Pipe | SMLS Pipe | Welded Pipe | |||
| < 2.375 | -0.031 to + 0.016 | – 0.031 to + 0.016 | 0.048 | 0.036 | ||
| ≥2.375 to 6.625 | 0.020D for | 0.015D for | ||||
| +/- 0.0075D | – 0.016 to + 0.063 | D/t≤75 | D/t≤75 | |||
| By agreement for | By agreement for | |||||
| D/t≤75 | D/t≤75 | |||||
| >6.625 to 24.000 | +/- 0.0075D | +/- 0.0075D, but max of 0.125 | +/- 0.005D, but max of 0.063 | 0.020D | 0.015D | |
| >24 to 56 | +/- 0.01D | +/- 0.005D but max of 0.160 | +/- 0.079 | +/- 0.063 | 0.015D for but max of 0.060 | 0.01D for but max of 0.500 |
| For | For | |||||
| D/t≤75 | D/t≤75 | |||||
| By agreement | By agreement | |||||
| for | for | |||||
| D/t≤75 | D/t≤75 | |||||
| >56 | As agreed | |||||
| Wall thickness | Tolerances a |
|---|---|
| t inches | inches |
| SMLS pipe b | |
| ≤ 0.157 | -1.2 |
| >0.157 to < 0.948 | + 0.150t / – 0.125t |
| ≥ 0.984 | + 0.146 or + 0.1t, whichever is the greater |
| – 0.120 or – 0.1t, whichever is the greater | |
| Welded pipe c,d | |
| ≤ 0.197 | +/- 0.020 |
| > 0.197 to < 0.591 | +/- 0.1t |
| ≥ 0.591 | +/- 0.060 |
API 5L X52 PSL2 Carbon Steel Seamless Pipe
