EN10208: Combustible Fluids Pipeline Tubes (Historical Standard)
EN10208 "Steel pipes for pipelines for combustible fluids" was the European standard specifically for pipeline tubes carrying flammable liquids and gases. It was the predecessor to the current EN10224 and EN ISO 3183 standards.
Status: Withdrawn in 2002, replaced by EN10224 (for onshore) and integrated into EN ISO 3183 (international pipeline standard).
1. Historical Structure of EN10208
The standard had two main parts that were critical for pipeline applications:
EN10208-1: Requirements for seamless and welded pipes of specified high toughness (for demanding applications like offshore, seismic zones, etc.)
EN10208-2: Requirements for seamless and welded pipes of standard toughness
Key Aspect: EN10208 was one of the first comprehensive European standards specifically addressing the needs of oil and gas transmission pipelines, including stringent requirements for Longitudinally Submerged Arc Welded (LSAW) pipes.
2. LSAW Pipe Requirements in EN10208
EN10208 provided detailed specifications for LSAW pipes used in high-pressure pipeline applications:
Table 1: Typical Steel Grades & Properties (EN10208 Historical)
| Steel Grade | Minimum Yield Strength (MPa) | Tensile Strength (MPa) | Charpy V-Notch Impact Requirements | Primary Application |
|---|---|---|---|---|
| L245NB | 245 | 415-655 | Specified at 0°C | Onshore pipelines |
| L290NB | 290 | 415-655 | Specified at 0°C | Onshore pipelines |
| L360NB | 360 | 460-685 | Specified at 0°C | Main transmission lines |
| L415NB | 415 | 515-760 | Specified at 0°C | High-pressure lines |
| L450QB | 450 | 535-760 | Specified at -20°C | Offshore/cold climate |
| L485QB | 485 | 570-760 | Specified at -30°C | Arctic/offshore |
| L555QB | 555 | 625-825 | Specified at -40°C | Deepwater offshore |
Notes:
L = Line pipe
Number = Minimum yield strength in MPa
NB = Normalized, Basic toughness
QB = Quenched & Tempered, High toughness
3. Manufacturing Requirements for LSAW Pipe
EN10208 specified rigorous requirements that became the benchmark for pipeline quality:
Key Manufacturing Requirements:
Plate Material: Steel plates to EN10028 or equivalent, with strict chemical composition controls (low sulfur, controlled carbon equivalent for weldability)
Forming Process: Typically UOE (U-ing, O-ing, Expanding) or JCO process
Welding: Multiple-pass submerged arc welding (SAW) with certified procedures
Heat Treatment: Full-body normalization or quenching & tempering for higher grades
Testing: Extensive mechanical testing, including:
Transverse and longitudinal tensile tests
Charpy impact tests at specified temperatures
Drop-weight tear tests (DWTT) for higher grades
Hardness tests
Table 2: Testing Requirements in EN10208
| Test Type | Frequency | Standard | Purpose |
|---|---|---|---|
| Hydrostatic Test | 100% of pipes | EN ISO 10893-4 | Proof of pressure integrity |
| Ultrasonic Testing | 100% of weld seam | EN 10246-10 | Weld defect detection |
| Radiographic Testing | Sampling or 100% | EN 1435 | Weld quality verification |
| Charpy Impact | Per heat/batch | EN 10045-1 | Fracture toughness |
| Hardness Survey | Per pipe/heat | EN 1043-1 | Weld zone properties |
| Flattening Test | Sampling | EN 10233 | Weld ductility |
4. Modern Replacements for EN10208
When EN10208 was withdrawn, its requirements were distributed among several modern standards:
Table 3: Current Standards Replacing EN10208
| Application Area | Current Standard | Key Features | Relationship to EN10208 |
|---|---|---|---|
| Onshore Pipelines | EN10224 | Non-alloy steel tubes for water/combustible fluids | Direct descendant, simpler requirements |
| International Pipelines | EN ISO 3183 | Petroleum/natural gas industry pipeline transportation systems | Comprehensive international standard |
| High-Toughness Applications | DNVGL-ST-F101 | Submarine pipeline systems | More stringent than EN10208-1 |
| General Pressure Pipes | EN10217-5 | Pressure purpose welded tubes | Similar welding requirements |
5. Typical LSAW Pipe Specifications Under EN10208 Legacy
Even though EN10208 is withdrawn, its specifications remain influential:
Table 4: Typical LSAW Pipe Specification (EN10208 Legacy)
| Parameter | Typical Specification | Notes |
|---|---|---|
| Diameter Range | 18" to 56" (457mm to 1422mm) | Common for transmission pipelines |
| Wall Thickness | 6mm to 40mm+ | Depends on pressure rating |
| Length | 12m standard, up to 18m | Double random lengths common |
| Tolerance | ±0.5% on OD, +15/-10% on WT | Stricter than structural pipes |
| End Preparation | Beveled ends for welding | Specific bevel angles for pipeline girth welding |
| Coating | External FBE/3LPE, internal epoxy | Corrosion protection |
6. Manufacturing Process for EN10208-Style LSAW Pipe
The manufacturing process that was typical for EN10208 pipes:
Plate Inspection → Ultrasonic testing of steel plates
Edge Preparation → Machining of plate edges
Pre-Bending → Plate ends pre-curved
U-Forming → Plate formed into U shape
O-Forming → U-shape closed into circular form
Welding → Internal and external SAW passes
Inspection → Ultrasonic testing of weld
Expanding → Mechanical expansion for roundness
X-Ray → Radiographic examination
Heat Treatment → Normalization or Q&T
Hydrostatic Test → Pressure test to specified level
Final Inspection → Dimensional, visual, NDT
Coating → External/internal anti-corrosion coating
7. Why EN10208 Was Important for LSAW Development
EN10208 played a crucial role in advancing LSAW pipe technology because it:
Standardized Testing: Established rigorous testing protocols still used today
Material Advancement: Pushed development of high-toughness steels (X70, X80, etc.)
Weld Quality: Set high standards for longitudinal seam integrity
Safety Focus: Emphasized fitness-for-service in hazardous fluid transport
Global Influence: Formed basis for many national and international standards
Conclusion
While EN10208 is no longer a current standard, its technical requirements and quality philosophy continue to influence modern LSAW pipe manufacturing for pipeline applications. When specifying LSAW pipe for combustible fluid service today, you would typically reference:
EN ISO 3183 for international pipeline projects
EN10224 for onshore European pipelines
DNVGL-ST-F101 for offshore/subsea applications
API 5L for global oil and gas projects
The legacy of EN10208 lives on in the stringent quality controls, comprehensive testing regimes, and safety-focused design principles that characterize modern high-quality LSAW pipeline production. When procuring LSAW pipe for critical applications, many specifications still reference "to EN10208 quality level" as a benchmark for excellence, even though the formal standard has been superseded.
