EN 10204 2.1 vs 2.2 vs 3.1 vs 3.2
EN 10204 defines four types of inspection documents for metallic products—pipes, fittings, flanges, plates, and structural steel. The standard specifies what information each document contains, who issues it, and whether test results are based on specific or non-specific inspection. Selecting the correct certificate type is critical for piping procurement: it determines the level of material traceability and quality assurance delivered with every shipment.
The four types are 2.1 (declaration of compliance), 2.2 (test report based on non-specific inspection), 3.1 (inspection certificate with specific test results), and 3.2 (inspection certificate validated by an independent body).
Certificate Types Compared
| Type | Name | Issued By | Test Basis | Content |
|---|---|---|---|---|
| 2.1 | Declaration of compliance | Manufacturer | No specific testing required | Statement that the product complies with the order requirements |
| 2.2 | Test report | Manufacturer | Non-specific inspection (tests on same grade, not necessarily same heat/lot) | Test results from production, but not traceable to the specific delivery |
| 3.1 | Inspection certificate 3.1 | Manufacturer\u0027s authorized representative | Specific inspection (tests on the actual delivered product) | Chemical analysis, mechanical properties, and NDT results from the specific heat and lot |
| 3.2 | Inspection certificate 3.2 | Manufacturer\u0027s representative + independent inspector (TPI) | Specific inspection (tests on the actual delivered product, witnessed by TPI) | Same as 3.1 but validated and co-signed by an independent inspection body |
What Each Certificate Contains
| Data Element | 2.1 | 2.2 | 3.1 | 3.2 |
|---|---|---|---|---|
| Manufacturer name | Yes | Yes | Yes | Yes |
| Product description | Yes | Yes | Yes | Yes |
| Order/specification reference | Yes | Yes | Yes | Yes |
| Declaration of compliance | Yes | Yes | Yes | Yes |
| Chemical composition (ladle analysis) | No | Optional | Yes (from specific heat) | Yes (from specific heat) |
| Mechanical properties (tensile, impact, hardness) | No | From non-specific tests | From specific lot/heat | From specific lot/heat |
| Heat number traceability | No | Not guaranteed | Yes | Yes |
| NDT results | No | No | If specified | If specified |
| Manufacturer\u0027s stamp/signature | Yes | Yes | Yes (authorized rep) | Yes (authorized rep) |
| Third-party inspector stamp/signature | No | No | No | Yes (TPI co-signs) |
When Each Type Is Required
| Application | Typical Certificate | Reason |
|---|---|---|
| Standard commercial piping (CS, non-critical) | 3.1 | Industry standard for ASTM/API materials |
| Critical/sour service piping (NACE) | 3.1 or 3.2 | Full traceability + hardness/impact verification |
| Structural steel beams (commercial) | 2.2 or 3.1 | Per EN 10025; 3.1 if specified |
| Pressure equipment (PED) | 3.1 minimum | EU Pressure Equipment Directive requires specific inspection |
| Nuclear piping | 3.2 | Third-party witnessed testing mandatory |
| Subsea pipelines | 3.2 | DNV/NORSOK require TPI witnessing |
| Bolting for pressure piping | 3.1 | Traceability to heat + mechanical verification |
| General industrial (low risk) | 2.1 or 2.2 | Cost-effective where full traceability is not required |
Cost and Lead Time Impact
| Certificate Type | Relative Cost | Lead Time Impact | Reason |
|---|---|---|---|
| 2.1 | Lowest | None | No testing required |
| 2.2 | Low | Minimal | Uses existing production test data |
| 3.1 | Moderate | +1-2 weeks | Specific testing per heat/lot; lab time required |
| 3.2 | Highest | +2-4 weeks | TPI must schedule, witness, and co-sign; coordination overhead |
Common Pitfalls
Relationship to ASTM/ASME
EN 10204 is a European standard, but it is universally referenced in international piping procurement. ASTM material specifications (A106, A312, A234, A105) do not reference EN 10204 directly; instead, they define their own testing and certification requirements. In practice, mills issue certificates that comply with both the ASTM specification and the EN 10204 type specified in the purchase order.
The equivalent US practice: a mill test report (MTR) with specific heat-traceable test results corresponds to EN 10204 Type 3.1. Adding third-party witness (TPI) corresponds to Type 3.2.
Certificate type is specified in the purchase order and verified during pipe inspections at the manufacturing facility as part of the inspection and test plan.
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