API 5L PSL2 Grade B Double-Sided Submerged Arc Welding (DSAW) Steel Pipe
Basic Overview
API 5L PSL2 Grade B DSAW steel pipe is a carbon steel line pipe manufactured to the American Petroleum Institute specification. The "Grade B" designation indicates a minimum yield strength of 35,000 psi (241 MPa) . PSL2 is the enhanced quality level with stricter requirements than PSL1, including mandatory impact testing, tighter chemistry controls, and maximum strength limits .
Key Specifications
| Attribute | Description |
|---|---|
| Standard | API 5L (46th Edition, aligned with ISO 3183) |
| PSL Level | PSL2 – enhanced quality |
| Grade | B (L245) |
| Min Yield Strength | 241-245 MPa (35,000 psi) |
| Max Yield Strength | 448-450 MPa (65,000 psi) |
| Min Tensile Strength | 414-415 MPa (60,000 psi) |
| Max Tensile Strength | 758-760 MPa (110,000 psi) |
| Yield-to-Tensile Ratio | ≤ 0.93 |
| Size Range (DSAW) | 16" to 72" OD (406 mm to 1829 mm) |
| Wall Thickness | 6.0 mm to 50 mm |
| Length | 6 m to 12 m standard |
Chemical Composition
| Element | Max % | PSL1 Comparison |
|---|---|---|
| Carbon (C) | 0.24% | PSL1: 0.26% |
| Manganese (Mn) | 1.20% | Similar |
| Phosphorus (P) | 0.025% | PSL1: 0.030% |
| Sulfur (S) | 0.015% | PSL1: 0.030% (50% reduction) |
| Carbon Equivalent (CEV) | 0.43% max | Not specified for PSL1 |
Source:
PSL1 vs PSL2 Comparison
| Feature | PSL1 | PSL2 |
|---|---|---|
| Carbon max | 0.26-0.28% | 0.24% |
| Sulfur max | 0.030% | 0.015% |
| Yield Strength | Min only (241 MPa) | Min & Max (241-450 MPa) |
| Tensile Strength | Min only (414 MPa) | Min & Max (414-758 MPa) |
| Yield-to-Tensile Ratio | Not specified | ≤ 0.93 |
| Impact Testing | Not required | Mandatory (27J at 0°C) |
| NDT Requirements | Standard | 100% UT mandatory |
| Traceability | Batch level | Pipe-by-pipe |
| Typical Use | General service | Critical service, sour service, low temp |
Source:
Delivery Conditions (Suffixes)
PSL2 Grade B DSAW pipes are supplied with suffixes indicating heat treatment :
| Suffix | Condition |
|---|---|
| BN | Normalized |
| BQ | Quenched and tempered |
| BR | As-rolled |
DSAW Manufacturing
Double-sided welding (inside + outside) forms a single high-quality weld nugget
Used for large diameter pipes (16" to 72"+)
Methods: JCOE or UOE forming
100% ultrasonic inspection (UT) of weld seam is mandatory for PSL2
Common Applications
Oil and gas transmission pipelines
Sour service (H₂S environments)
Low-temperature service
Offshore pipelines
Water transmission mains
Summary
API 5L PSL2 Grade B DSAW steel pipe is the entry-level PSL2 line pipe grade. Key benefits over PSL1 include:
Mandatory Charpy impact testing (27J at 0°C)
50% lower sulfur content (0.015% vs 0.030%)
Maximum strength limits (241-450 MPa)
Yield-to-tensile ratio ≤ 0.93
100% ultrasonic inspection of weld seam
Full pipe-by-pipe traceability
Available in large diameters from 16" to 72"+ for DSAW manufacturing.
When ordering, specify: API 5L PSL2 Grade B, DSAW, Size (OD x WT), Length, Delivery Condition (BN/BQ/BR), Impact test temperature.
