EN 10204 for Electric Resistance Welded (ERW) Pipe
Basic Overview
EN 10204 is not a pipe manufacturing standard – it is a European standard that specifies the types of inspection documents provided with metallic products, including ERW pipes. It defines the level of traceability and certification accompanying the pipe delivery.
What EN 10204 Actually Is
| Aspect | Description |
|---|---|
| Standard | EN 10204:2004 – Metallic products – Types of inspection documents |
| Purpose | Defines the different types of inspection documents supplied to the purchaser for the delivery of metallic products |
| Applicability | Applies to all metallic products: plates, sheets, bars, forgings, castings, seamless pipes, welded pipes, whatever their production method |
| Also Applies To | May also apply to non-metallic products |
| Not a Product Spec | Used in conjunction with product specifications that define technical delivery conditions |
| Key Point | EN 10204 certifies the test results and traceability, not the pipe grade itself |
EN 10204 Certificate Types for ERW Pipe
There are four main types of EN 10204 certificates, ranging from basic to highest integrity :
2.1 Certificate – Declaration of Compliance
| Aspect | Description |
|---|---|
| Level | Lowest level certification |
| What It States | Manufacturer declares products were made according to order requirements |
| Test Results | No test results included |
| Issuer | Manufacturer's representative |
| Typical Use | Non-critical applications, standard stock items |
2.2 Certificate – Test Report
| Aspect | Description |
|---|---|
| Level | Intermediate level |
| What It States | Products comply with order requirements |
| Test Results | Test results included, but based on representative samples (not necessarily the actual supplied product) |
| Issuer | Manufacturer's QA department (no separation from manufacturing) |
| Limitation | Results may not reflect the actual supplied product – relies on manufacturer's QA system |
3.1 Certificate – Inspection Certificate (Most Common for ERW Pipes)
| Aspect | Description |
|---|---|
| Level | High-level certification |
| What It States | Products comply with order requirements based on actual testing of the supplied products |
| Test Results | Results from actual supplied materials included |
| Key Requirement | Testing department must be formally independent from manufacturing department |
| Issuer | Manufacturer's independent testing department |
| Typical Use | Standard for pressure equipment, critical applications |
| Commonly Seen As | "Mill Test Certificate: EN 10204/3.1B" on supplier datasheets |
| ISO Requirement | Manufacturer must have ISO 9001 certification to issue 3.1 certificates |
3.2 Certificate – Witnessed Inspection Certificate (Highest Level)
| Aspect | Description |
|---|---|
| Level | Most stringent certification |
| What It States | Products comply with order requirements based on actual testing of supplied products, witnessed by independent third party |
| Test Results | Results from actual supplied materials included |
| Key Requirement | Independent third party (EU-notified body) must witness testing and verify results |
| Issuer | Manufacturer with third-party validation |
| Typical Use | Pressure equipment directive (PED) compliance, critical safety applications |
| Required For | Export of large equipment, pressure vessels to Europe |
Certificate Comparison Summary
| Level | Test Results Included? | Based on Actual Product? | Independent Testing? | Third-Party Witness? |
|---|---|---|---|---|
| 2.1 | ❌ No | ❌ No | ❌ No | ❌ No |
| 2.2 | ✅ Yes | ❌ No (representative samples) | ❌ No | ❌ No |
| 3.1 | ✅ Yes | ✅ Yes | ✅ Yes (internal independence) | ❌ No |
| 3.2 | ✅ Yes | ✅ Yes | ✅ Yes (internal) | ✅ Yes (external) |
Source:
EN 10204 Tests Typically Included for ERW Pipe
When an ERW pipe is supplied with EN 10204 certification, the following tests are typically documented :
| Test Type | Specific Tests |
|---|---|
| Chemical Analysis | Carbon, manganese, phosphorus, sulfur, silicon, alloying elements |
| Mechanical Properties | Tensile strength, yield strength, elongation |
| Hardness Testing | Brinell, Rockwell, or Vickers as applicable |
| Bend Testing | Flattening test, bending test |
| Impact Testing | Charpy V-notch (when specified for low temperature) |
| Hydrostatic Test | Pressure integrity verification |
| NDT Testing | Ultrasonic, eddy current, X-ray examination as applicable |
| Dimensional Inspection | Exterior size, wall thickness, straightness |
| Visual Inspection | Surface finish, weld quality |
When Each Certificate Type is Used for ERW Pipe
| Application | Recommended Certificate | Reason |
|---|---|---|
| General construction, fencing, handrails | 2.2 | Cost-effective, basic compliance |
| Structural applications (buildings, bridges) | 2.2 or 3.1 | Depends on specification requirements |
| Industrial fluid lines (non-critical) | 3.1 | Traceability to actual product |
| Pressure equipment (PED compliance) | 3.1 or 3.2 | Required by Pressure Equipment Directive |
| Oil and gas pipelines | 3.1 | Industry standard for traceability |
| Export to Europe (critical equipment) | 3.2 | Often specified for large projects |
| Sour service (H₂S environments) | 3.1 with specific tests | Requires additional NACE testing documentation |
Common ERW Pipe Standards Paired with EN 10204 Certification
EN 10204 certificates are typically provided alongside these pipe manufacturing standards :
| Standard | Typical Grades | Application |
|---|---|---|
| API 5L | Gr.B, X42, X46, X52, X56, X60 | Oil and gas pipelines |
| ASTM A53 | Gr.A, Gr.B | General piping |
| EN 10217 | S235, S275, S355 | Welded steel tubes for pressure purposes |
| EN 10224 | Various | Water pipes |
| EN 10255 | Various | Threaded tubes |
| ASTM A795 | Gr.A, Gr.B | Fire sprinkler systems |
| DIN 17100 | St37-2, St44, St52 | Structural applications |
| GB/T 3091 | Q235, Q345 | General piping |
Key Points to Remember
EN 10204 is NOT a pipe grade – it's a certificate type that documents testing and traceability
3.1 is the industry standard for most critical ERW pipe applications
3.2 is required for:
Pressure Equipment Directive (PED) compliance
Export of large equipment to Europe
Projects explicitly requiring third-party witness
2.2 may not reflect your actual pipe – test results are from representative samples, not your specific shipment
Always specify the certificate type in your order – don't assume what you'll receive
Final Takeaway: EN 10204 defines the inspection documents for ERW pipes and other metallic products. For critical applications requiring full traceability to the actual delivered pipe, specify EN 10204 3.1 (manufacturer's independent testing) or 3.2 (with third-party witness). The certificate type is as important as the pipe grade itself for quality assurance and regulatory compliance.
