Inspection certificate 3.1 or 2.2? Test certificates to EN 10204
For safety-relevant pipework the goods alone are not enough – the matching documentation is required. EN 10204 distinguishes four types of inspection document. Which one you need is decided before ordering, not afterwards.
The four types at a glance
| Type | Designation | Contains | Validated by |
|---|---|---|---|
| 2.1 | Declaration of compliance | Compliance with the order, no test results | Manufacturer |
| 2.2 | Test report | Compliance plus results of non-specific testing | Manufacturer |
| 3.1 | Inspection certificate | Results of testing on the delivered batch | Manufacturer's inspection representative, independent of production |
| 3.2 | Inspection certificate | As 3.1, additionally countersigned | Additionally purchaser or notified body |
The decisive difference: with 2.2, some test from current production is documented. With 3.1 the figures are those of your batch. Only from 3.1 upwards can the delivered material be traced unambiguously to a heat.
What a 3.1 certificate contains
An inspection certificate 3.1 is more than a stamp. It typically states:
- Material and standard – for example 16Mo3 to EN 10216-2
- Heat and batch number – the basis of traceability
- Chemical composition – heat analysis, sometimes product analysis
- Mechanical properties – yield strength, tensile strength, elongation, impact energy
- Heat treatment condition – normalised, quenched and tempered, solution annealed
- Non-destructive testing – ultrasonic, eddy current or radiography, where required
- Pressure test – with test pressure and holding time
Which certificate when?
| Application | Customary |
|---|---|
| Water, ventilation, building services | 2.1 or 2.2 |
| General mechanical and structural engineering | 2.2 |
| Pressure equipment, chemicals, process technology | 3.1 |
| Boiler and power plant construction, steam | 3.1, often 3.2 |
| Pressure Equipment Directive, higher category | 3.1 or 3.2 with notified body |
| Shipbuilding with classification society | 3.2 with survey |
Why it pays to decide early
A certificate cannot be produced retrospectively. If material was ordered without 3.1 and the batch has been mixed in the warehouse, no amount of goodwill will help – the only remedy is to return the goods and reorder. That costs weeks.
The required certificate type therefore belongs in the enquiry, not only in the order. It noticeably affects price and lead time: material with 3.1 comes from a documented batch that must be traced at the mill.
When the certificate does not match
Three cases occur regularly in practice:
- No certificate at all. Ordered without specification, delivered without documentation. This cannot be remedied afterwards – the batch is no longer clearly attributable.
- Certificate does not match the delivery. Batch number on paper and marking on the pipe differ. That is grounds for complaint, not a formality.
- Wrong type. 2.2 delivered where 3.1 was required. That will not pass inspection, even if the material is correct.
At goods inward, therefore, check not only quantity but also whether marking on the component and the details in the certificate match. With us, documentation is assigned to the order and archived – in case it is requested years later during an overhaul.
Traceability in practice
The chain runs from the heat through the semi-finished product to the installed component. Every item carries a marking – material, batch, manufacturer – that can be matched to the certificate. For power plant and boiler components this attribution is not optional but part of the inspection.
On request we supply with inspection certificate 3.1 to EN 10204, where required 3.2 with survey by a notified body – for pipes, flanges and fittings, valves and special parts. Documentation is assigned to the order and archived.
Frequently Asked Questions
What is the difference between 2.2 and 3.1 to EN 10204?
With 2.2 a test from current production is documented; with 3.1 the figures are those of the delivered batch, confirmed by an inspection representative independent of production. Only from 3.1 upwards is the material traceable to a specific heat.
What does an inspection certificate 3.1 contain?
Material and standard, heat and batch number, chemical composition, mechanical properties, heat treatment condition, plus non-destructive testing and pressure test where required.
When do I need 3.2 instead of 3.1?
When the purchaser or a notified body must countersign. Customary in boiler and power plant construction, for pressure equipment in higher categories and in shipbuilding with a classification society.
Can a certificate be issued retrospectively?
No. If the batch can no longer be clearly attributed in the warehouse, the documentation cannot be recreated. The required certificate type therefore belongs in the enquiry.
What should be checked at goods inward?
That the marking on the component and the details in the certificate match, in particular the batch number. Any discrepancy is grounds for complaint.
Do you need exactly these parts?
Grade, size, pressure rating and quantity are enough – you usually receive your quote the same day, with an inspection certificate 3.1 on request.
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