API 5L GR.B PSL2 line pipe is a high-performance tubular product widely used in the oil and gas industry. As the second quality level under API 5L, it imposes more stringent requirements than GR.B PSL1 regarding chemical composition, mechanical properties, dimensional tolerances, and non-destructive testing. This ensures suitability for high-pressure transmission, long-distance pipelines, and complex geological environments.
API 5L GR.B PSL2 pipes are extensively deployed in long-distance transmission pipelines, gathering systems, urban gas networks, and industrial piping across oil & gas, chemical, and power sectors. Particularly in extreme operating conditions involving high pressure, elevated temperature, or corrosive media, their seamless variants serve as critical components due to exceptional performance and reliability.
Chemical composition % of API 5L Grade B psl2 carbon steel seamless pipe
| CHEMICAL COMPOSITION | |||||||||||
| Mass fraction, based upon heat and product analysis % maximum | CARBON EQUIVALENT a | ||||||||||
| % MAXIMUM | |||||||||||
| Cb | Si | Mnb | P | S | V | Nb | Ti | Other | CEIIW | CEPcm | |
| SEAMLESS & WELDED PIPES | |||||||||||
| L245R OR BR | 0.24 | 0.4 | 1.2 | 0.025 | 0.015 | c | c | 0.04 | e | 0.43 | 0.25 |
| L245Q OR BQ | 0.18 | 0.45 | 1.4 | 0.025 | 0.015 | 0.05 | 0.05 | 0.04 | e | 0.43 | 0.25 |
| WELDED PIPE | |||||||||||
| L245M OR BM | 0.22 | 0.45 | 1.2 | 0.025 | 0.015 | 0.05 | 0.05 | 0.04 | e | 0.43 | 0.25 |
Mechanical properties of API 5L Grade B psl2 carbon steel seamless pipe
| MECHANICAL REQUIREMENTS | |||
|
Y.S |
T.S |
ELONGATION |
|
|
Mpa(psi) |
Mpa(psi) |
||
|
min |
min |
min |
|
|
245(35 500) |
450(50 300) |
f |
|
API 5L GR.B PSL1 vs PSL2 Key Differences
| Parameter | PSL1 (Basic) | PSL2 (Enhanced) | Technical Impact |
|---|---|---|---|
| Chemical Composition | |||
| - CEpcm | ≤0.43% | ≤0.43% (same) | Equivalent requirement |
| - Sulfur (S) | ≤0.030% | ≤0.015% (50% stricter) | ↑ SSC Resistance |
| - Phosphorus (P) | ≤0.030% | ≤0.025% | ↑ Low-Temperature Toughness |
| Mechanical Properties | |||
| - Yield Strength | ≥240 MPa | ≥240 MPa (same) | Consistent baseline |
| - Charpy Impact Test | Optional | Mandatory (≥40J @ -20°C) | ↑ Cryogenic Safety |
| - Hardness Limit | Not specified | ≤250 HBW | Prevents HIC/SSC Failure |
| Non-Destructive Testing | |||
| - Ultrasonic Test (UT) | Sampling | 100% Full-body | ↑ Defect Detection |
| - Radiographic Test (RT) | Not required | 100% on welds/HAZ | For welded pipes only |
| Dimensional Tolerance | |||
| - Wall Thickness | ±12.5% | ±10.0% (tighter) | ↑ Precision by 25% |
| - Ovality | ≤1.5% | ≤1.0% | ↑ Sealing Reliability |
| Typical Applications | Low-pressure/non-corrosive (e.g., water) | High-pressure/corrosive service (e.g., sour gas) | Critical for harsh environments |
Production Process of API 5L GR.B PSL2 Seamless Pipe
Steelmaking & Continuous Casting
Advanced converter/electric furnace smelting with strict chemical control (Ceq≤0.43%)
Secondary refining (e.g., LF/RH furnaces) for steel purity [H]≤1.5ppm
Electromagnetic stirring during casting ensuring homogeneous billet structure
Hot Rolling & Piercing
Billet heating at 1200±20°C → Rolling into tube blanks
Hollow shell formation via cross-rolling piercing or press piercing
Critical control: Deformation ratio ≥6:1 for grain refinement
Cold Working (Optional)
Cold rolling/drawing for ±0.1mm dimensional precision
Stress-relief annealing at 650-700°C (mandatory for cold-worked pipes)
Heat Treatment
Normalizing: 880-920°C air cooling → Enhances toughness
Quenching & Tempering:
Quenching (900°C water spray) → Tempering (600°C) → Achieves ≥360MPa yield strength
Non-Destructive Testing
100% coverage required for PSL2:
UT (detects ≥1.6mm flaws per ASTM E213)
ET (surface defects ≤0.3mm depth)
RT (wall thickness variation ≤±5%)
API 5L GRB PSL2 carbon line pipe factory
