EN 10217 S355J2 Electric Resistance Welded (ERW) Pipe
Important Clarification: Grade Designation
Note: EN 10217 S355J2 represents a specification combination where structural and pressure standards intersect. EN 10217 (pressure tubes) officially uses P-prefix grades (e.g., P235, P265, P355) . S355J2 is a structural steel grade defined in EN 10025 with guaranteed impact properties at -20°C .
For pressure applications requiring S355J2 properties, the technically correct EN 10217 grade is P355NH (fine-grain normalized steel) .
Correct Grade Mapping
| Intended S355J2 | Correct EN 10217 Grade | Standard Part | Key Rationale |
|---|---|---|---|
| S355J2 (27J @ -20°C) | P355NH | EN 10217-3 (Fine grain steels) | Fine-grain normalized steel with guaranteed -20°C impact properties |
| General pressure use | P355NH TC1 | EN 10217-3 | Standard quality, sufficient for most applications |
| Critical service | P355NH TC2 | EN 10217-3 | Enhanced quality with ultrasonic weld examination |
| Structural engineering | S355J2H | EN 10219 | Cold-formed structural hollow sections (not pressure) |
Key Features of EN 10217 S355J2 (as P355NH) ERW Pipe
| Feature | Description |
|---|---|
| Material Type | Fine-grain, fully-killed carbon-manganese steel |
| Manufacturing | High Frequency Welded (HFW) or Electric Resistance Welded (ERW) – longitudinal weld seam fully normalized |
| Yield Strength | 355 MPa minimum (51,500 psi) |
| Tensile Strength | 490-650 MPa (71,000-94,000 psi) |
| Elongation | 22% minimum (longitudinal) |
| Impact Properties | 27J minimum at -20°C (matches J2 designation) |
| Key Advantages | High strength-to-weight ratio, excellent low-temperature toughness, fine-grain structure |
| Temperature Range | -20°C to +400°C for pressure applications |
| Certification | EN 10204 3.1 inspection certificate standard |
Chemical Composition (P355NH per EN 10217-3)
| Element | Content (%) | Notes |
|---|---|---|
| Carbon (C) | 0.20 max | Low carbon for weldability |
| Silicon (Si) | 0.10-0.50 | |
| Manganese (Mn) | 0.90-1.65 | Provides strength |
| Phosphorus (P) | 0.025 max | Tight control |
| Sulfur (S) | 0.020 max | Critical for low-temperature toughness |
| Aluminum (Al) | 0.02 min | Grain refinement |
| Niobium (Nb) | 0.05 max | Micro-alloying |
| Vanadium (V) | 0.10 max | Micro-alloying |
| Titanium (Ti) | 0.04 max | Micro-alloying |
Note: EN 10217 has stricter sulfur control (S ≤ 0.020%) compared to structural S355J2 (S ≤ 0.045%), ensuring better low-temperature toughness and weld integrity .
Mechanical Properties Comparison
| Grade | Yield Strength (MPa) min | Tensile Strength (MPa) | Elongation % | Impact Energy (J) / Temp |
|---|---|---|---|---|
| S235J2 | 235 | 360-510 | 24 | 27 @ -20°C |
| S275J2 | 275 | 430-580 | 22 | 27 @ -20°C |
| S355J2 | 355 | 490-630 | 22 | 27 @ -20°C |
| P355NH | 355 | 490-650 | 22 | 27 @ -20°C (transverse) |
EN 10217 Parts for S355J2/P355 Materials
| Part | Title | Applicable Grades | Key Application |
|---|---|---|---|
| Part 3 | Welded tubes of fine grain steels | P355NH, P355NL1, P355NL2 | Pressure applications requiring low-temperature toughness (-20°C to -50°C) |
| Part 4 | Non-alloy tubes with specified low temperature properties | P215NL, P265NL | Lower strength low-temperature service |
| Part 2 | Tubes with specified elevated temperature properties | P355GH | High-temperature service (above 400°C) |
Test Categories: TC1 vs. TC2
| Category | Description | Typical Application |
|---|---|---|
| TC1 | Standard quality, without mandatory ultrasonic testing of weld seam | General pressure applications, sufficient for most uses |
| TC2 | Enhanced quality, with mandatory ultrasonic testing of weld seam | Critical service, low-temperature applications, higher integrity requirements |
Multi-Certification Examples (Tata Steel Inflow™ Plus 355)
Major manufacturers offer multi-certified tubes satisfying multiple standards :
| Standard | Grade |
|---|---|
| Primary Standard | EN 10217-3 Grade P355NH |
| Structural Engineering | EN 10219 Grade S355J2H (for sizes ≥219.1mm OD) |
| German Standards | DIN1626 St52.0N/G, DIN1628 St52.4, DIN17178 WSt E 355 |
| Seamless Equivalents | DIN1629 St52.0N, DIN1630 St52.4, DIN17179 WSt E355 |
Size Availability & Delivery Conditions
| Parameter | Hot-Finished | Weld Line Annealed (WLA) |
|---|---|---|
| Outside Diameter | 17.2 mm to 193.7 mm | 219.1 mm to 508 mm |
| Wall Thickness | 1.8 mm to 16 mm | Up to 25 mm |
| Delivery Condition | Normalized throughout | Weld seam normalized |
| Weld Bead | Fully removed (OD & ID) | Fully removed |
Testing & Inspection Requirements
| Test Type | Purpose | Requirement |
|---|---|---|
| Chemical Analysis | Verify composition per EN 10217 limits | Per cast/heat |
| Tensile Test | Confirm yield and tensile strength | Per batch |
| Flattening Test | Verify ductility across weld seam | Mandatory |
| Bend Test | Check weld integrity and formability | Mandatory |
| Impact Test | Charpy V-notch at -20°C (J2 requirement) | 27J minimum |
| Hydrostatic Test | Proof of leak-tightness | ≥1.5 × design pressure, ≥10-15 seconds hold |
| NDT of Weld Seam | Eddy current (EN ISO 10893-2) or ultrasonic (EN ISO 10893-10) | 100% examination (mandatory for TC2) |
| Ultrasonic Testing | Weld + 10mm base metal on both sides | Sensitivity Φ3.2mm FBH (typical) |
Common Applications
| Industry | Applications |
|---|---|
| Pressure Equipment | Boilers, heat exchangers, pressure vessels requiring low-temperature toughness |
| Oil & Gas | Medium-pressure pipelines, process plant piping, onshore gas lines |
| Petrochemical | Industrial conveyance, process equipment for moderate cold climates |
| Power Generation | Steam services, elevated temperature lines with low-temperature startup |
| HVAC | Specialist industrial heating and cooling systems |
| Fire Protection | Fire sprinkler systems in unheated buildings |
| Structural | High-strength pressure-containing elements in cold environments |
Temperature Range & PED Compliance
| Aspect | Requirement |
|---|---|
| Standard Temperature Range | -20°C to +400°C |
| Low Temperature Option | Possible for lower temperatures upon request with full application details |
| PED Compliance | Fully aligned with Pressure Equipment Directive 2014/68/EU |
| PED Categories | Suitable for equipment in categories I, II, III, or IV |
| AD2000 Compliance | Aligned with AD2000 Merkblatt W4 |
Pressure Ratings (Reference Values)
Typical pressure ratings for P355NH (S355J2-equivalent) material (based on Tata Steel Inflow™ Plus 355 data) :
| OD (mm) | Thickness (mm) | Designation | Recommended Max Operating Pressure (bar) |
|---|---|---|---|
| 60.3 | 3.91 | STD | 219 |
| 5.54 | XS | 307 | |
| 114.3 | 6.02 | STD | 179 |
| 8.56 | XS | 256 | |
| 219.1 | 8.18 | STD | 128 |
| 12.7 | XS | 198 | |
| 323.9 | 9.53 | STD | 101 |
| 12.7 | XS | 134 |
Note: Pressure ratings calculated based on ASME B31.3 and European guidelines for straight pipes with full penetration welded joints. Actual system design must consider corrosion allowance, bending, fittings, and applicable codes .
Surface Finish & Protection Options
| Coating Type | Application |
|---|---|
| Self-colour (bare) | Standard mill finish, indoor use |
| Varnish coating | Short-term corrosion protection |
| Primer-painted | Basic corrosion protection |
| 3LPE / FBE | Buried pipelines, harsh environments |
| Epoxy coating | Enhanced corrosion protection |
| Galvanized | Outdoor exposed applications |
Certification
| Certificate Type | Description | Typical Use |
|---|---|---|
| EN 10204 3.1 | Manufacturer's independent testing department certifies results from actual supplied products | Standard for pressure applications |
| EN 10204 3.2 | Third-party witnessed testing | Critical applications, specific project requirements |
Mill Test Certificate must include: chemical composition, mechanical properties, NDT results, hydrostatic test results, heat treatment details.
International Equivalents (Approximate)
| Standard | Equivalent Grade | Notes |
|---|---|---|
| ASTM A106 | Gr.B/C | Lower strength (240/275 MPa vs. 355 MPa) |
| ASTM A333 | Gr.6 (low temp) | Lower strength (240 MPa) |
| API 5L | X52 | Yield 360 MPa – slightly higher |
| ISO 3183 | L360 | Similar to X52 |
| DIN 1629 | St52.0N | Historical German equivalent |
| DIN 17178 | WSt E 355 | Historical German equivalent |
| GB/T 3091 | Q355 | Chinese equivalent |
Important Selection Notes
1. Correct Grade Designation
For pressure applications requiring S355J2 properties, specify P355NH (EN 10217-3)
S355J2H is for structural hollow sections (EN 10219), not pressure purposes
Major manufacturers offer multi-certified tubes meeting both standards
2. Temperature Considerations
Standard range: -20°C to +400°C for pressure applications
For temperatures below -20°C, specify P355NL1 (-40°C) or P355NL2 (-50°C)
For temperatures above 400°C, consider P355GH (EN 10217-2)
3. Quality Level Selection
TC1: Standard quality, sufficient for most applications
TC2: Enhanced quality with ultrasonic weld examination – recommended for low-temperature service and critical applications
4. Advantages over Lower Grades
Higher strength allows thinner walls for same pressure rating
Weight savings reduce supporting structure requirements
Fine-grain structure provides better low-temperature toughness
Cost-effective alternative to seamless tubes
5. When to Choose S355J2/P355NH
Applications requiring guaranteed toughness at -20°C
Pressure equipment in moderate cold climates
Industrial conveyance where higher strength reduces wall thickness
Projects requiring multi-certified materials for flexibility
Final Takeaway: EN 10217 S355J2 ERW Pipe (technically P355NH per EN 10217-3) is a high-strength, fine-grain steel welded tube designed for pressure applications requiring guaranteed low-temperature toughness at -20°C. With minimum yield strength of 355 MPa and impact properties of 27J at -20°C (J2 designation), it offers an excellent balance of strength, toughness, and weldability for demanding applications in oil & gas, petrochemical, power generation, and industrial pressure systems. For critical service, specify EN 10217-3 P355NH with TC2 test category and EN 10204 3.1 certification. Major manufacturers offer multi-certified tubes that also meet EN 10219 S355J2H structural requirements, providing flexibility for projects where both pressure and structural certifications are needed.
