API 5L refers to the execution standard for pipeline pipes, covering two main categories: seamless steel pipes and welded steel pipes. These pipes are widely used in oil and natural gas transportation systems. Under the API 5L standard, there are various material grades for steel pipes, such as GR.B, X42, X46, X52, X56, X60, X65, X70, and higher grades. These grades indicate the strength and pressure resistance of the steel pipes, with higher numbers representing greater yield strength.
These steels are primarily low-carbon alloy steels, with appropriate alloying elements added to enhance their comprehensive properties, including tensile strength, yield strength, elongation, weldability, and corrosion resistance. For example, Grade X52 steel pipes have a minimum tensile strength of 414 MPa and a minimum yield strength of 290 MPa. These high-performance parameters ensure the stability and safety of the pipes in harsh environments.
Steel Grade:
1) Seamless Line Pipe For General Service
BN/L245N, X42N/L290N, X46N/L320N, X52N/L360N, X52Q/L360Q, X56N/L390N, X60N/L415N, X60Q/L415Q, X65Q/L450Q, X70Q/L485Q, X80Q/L555Q, X90Q/L625Q
2) Seamless Line Pipe For Sour Service
BNS/L245NS, X42NS/L290NS, X46NS/L320NS, X52NS/L360NS, X52QS/L360QS, X56NS/L390NS, X60QS/L415QS, X65QS/L450QS, X70QS/L485QS
3) Seamless Line Pipe For Ocean Service
BNO/L245NO, X42NO/L290NO, X46NO/L320NO, X52NO/L360NO, X52QO/L360QO, X56NO/L390NO, X60QO/L415QO, X65QO/L450QO, X70QO/L485QO, X80QO/L555QO, X90QO/L625QO.
4) Welded Line Pipe for General Service
BR/L245R, L290R/X42R, L245N/BN, L290N/X42N, L320N/X46N, L360N/X52N, L390N/X56N, L415N/X60N
BQ/L245Q, L290Q/X42Q, L320Q/X46Q, L360Q/X52Q, L390Q/X56Q, L415Q/X60Q, L450Q/X65Q, L485Q/X70Q, L555Q/X80Q, L625Q/X90Q, L690Q/X100Q.
BM/L245M, L290M/X42M, L320M/X46M, L360M/X52M, L390M/X56M, L415M/X60M, L450M/X65M, L485M/X70M, L555M/X80M,
L625M/X90M, L690M/X100M.
5) Welded Line Pipe for Sour Service
BMS/BNS/BQS/L245MS/L245NS/L245QS, L290MS/L290NS/L290QS/X42MS/X42NS/X42QS, L320MS/L320NS/L320QS/X46MS/X46NS/X46QS, L360MS/L360NS/L360QS/X52MS/X52NS/X52QS, L390MS/L390NS/L390QS/X56MS/X56NS/X56QS, L415MS/L415NS/L415QS/X60MS/X60NS/X60QS, L450MS/L450NS/L450QS/X65MS/X65NS/X65QS, L485MS/L485NS/L485QS/X70MS/X70NS/X70QS, L555MS/L555NS/L55QS/X80MS/X80NS/X80QS
Sizes:
Maximum diameter: 36" (914.4mm) minimum diameter: 1/2" (21.3mm)
Maximum thickness: 60mm mininmum thickness: 2.11mm
SCH: SCH10,SCH20,STD,SCH40,SCH60,XS,SCH80,SCH100,SCH120,SCH160,XXS
Coating
| 3PE Coating | 3PP Coating | FBE Coating | Epoxy Coating | Special Painting |
Chemical components & mechanical properties
| Standard | Grade | Chemical Components (%) | Mechanical Properties | ||||||
| API 5L PSL1 | A | 0.22 | - | 0.90 | 0.030 | 0.030 | ≥331 | ≥207 | |
| B | 0.28 | - | 1.20 | 0.030 | 0.030 | ≥414 | ≥241 | ||
| X42 | 0.28 | - | 1.30 | 0.030 | 0.030 | ≥414 | ≥290 | ||
| X46 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥434 | ≥317 | ||
| X52 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥455 | ≥359 | ||
| X56 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥490 | ≥386 | ||
| X60 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥517 | ≥448 | ||
| X65 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥531 | ≥448 | ||
| X70 | 0.28 | - | 1.40 | 0.030 | 0.030 | ≥565 | ≥483 | ||
| API 5L PSL2 | B | 0.24 | - | 1.20 | 0.025 | 0.015 | ≥414 | ≥241 | |
| X42 | 0.24 | - | 1.30 | 0.025 | 0.015 | ≥414 | ≥290 | ||
| X46 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥434 | ≥317 | ||
| X52 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥455 | ≥359 | ||
| X56 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥490 | ≥386 | ||
| X60 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥517 | ≥414 | ||
| X65 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥531 | ≥448 | ||
| X70 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥565 | ≥483 | ||
| X80 | 0.24 | - | 1.40 | 0.025 | 0.015 | ≥621 | ≥552 | ||
Tolerances of carbon seamless steel pipe
| Pipe types | Pipe sizes(mm) | Tolerances |
| Hot rolled | OD<50 | ±0.50mm |
| OD≥50 | ±1% | |
| WT<4 | ±12.5% | |
| WT 4～20 | +15%, -12.5% | |
| WT>20 | ±12.5% | |
| Cold drawn | OD 6～10 | ±0.20mm |
| OD 10～30 | ±0.40mm | |
| OD 30～50 | ±0.45 | |
| OD>50 | ±1% | |
| WT≤1 | ±0.15mm | |
| WT 1～3 | +15%, -10% | |
| WT >3 | +12.5%, -10% |
Ends design:
1) Bevel the welding ends to an angle of 30°, +5°, -0°, with a root face of 1/16", +/- 1/32". The bevel shall form a V groove with an included angle of 60°+10/-0. The root opening shall be 1/16", +/- 1/32" according to ANSI B16.25.
2) Plain or straight ends.
3) Threaded ends with coupling or without coupling according to API Spec. 5B.
