Buyers who order stainless and nickel alloy pipe into Europe are usually told to ask for an EN 10204 certificate, and are often then handed a document whose label says one thing and whose content says another. The four document types in EN 10204 differ in a single, decisive respect: who is allowed to sign, and how independently that person stands from the production that made the material. Everything else follows from that.
EN 10204 is the European standard for the types of inspection document that accompany a metal product. The current edition is BS EN 10204:2004, Metallic products. Types of inspection documents, published 25 October 2004, which replaced BS EN 10204:1991 and is now withdrawn. The 2004 edition is identical to EN 10204:2004, and its own contents list runs to scope, terms and definitions, inspection documents based on non-specific inspection, inspection documents based on specific inspection, validation and transmission of inspection documents, transmission by an intermediary, summary of inspection documents, the relationship to the Essential Requirements of Directive 97/23/EC, and a bibliography.
The four document types
| Type | Document | What it contains | Who validates it |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | Statement of compliance with the order, without inclusion of test results | The manufacturer |
| 2.2 | Test report | Statement of compliance with the order, with results of non-specific inspection | The manufacturer |
| 3.1 | Inspection certificate 3.1 | Statement of compliance with the order, with results of specific inspection | The manufacturer’s authorised inspection representative, independent of the manufacturing department |
| 3.2 | Inspection certificate 3.2 | Statement of compliance with the order, with results of specific inspection | The manufacturer’s authorised inspection representative independent of the manufacturing department, and either the purchaser’s authorised inspection representative or the inspector designated by the official regulations |
The distinction between a test report and an inspection certificate is the distinction that gets missed most often. Non-specific inspection is carried out by the manufacturer in accordance with its own procedures to assess whether products defined by the same product specification and made by the same manufacturing process comply with the order. The standard is explicit about the consequence: the products inspected are not necessarily the products actually supplied. Specific inspection, by contrast, is carried out before delivery, according to the product specification, on the products to be supplied or on test units of which the product supplied forms part, in order to verify that those products comply with the requirements of the order.
That is why a 2.2 test report is not a substitute for a 3.1, even when both carry chemical and tensile figures on paper. One reports on the product family and the process. The other reports on your material.
What a 3.2 actually adds, and what it does not
A Type 3.2 certificate is not better steel. It is a different verification arrangement. The grade, the chemical composition, the mechanical properties and the acceptance limits all come from the material specification and the order, not from the certificate type. What the 3.2 adds is a second, independent validating party: the purchaser’s authorised representative, or the inspector designated by official regulations, alongside the manufacturer’s own authorised representative.
Two consequences follow for procurement. The first is that requesting 3.2 after material has been bought is a change of inspection arrangements, not a clerical correction, and it cannot be satisfied by adding a stamp to an existing 3.1. The second is that the inspection scope has to be agreed before production, not after: the test unit, the tests to be carried out, the witnessing arrangements and the accepted inspector all have to be settled in advance, because the standard permits the manufacturer to transfer relevant test results from specific inspection on primary or incoming products to the certificate, provided the manufacturer operates traceability procedures and can supply the corresponding inspection documents.
There is one further trap worth naming. Independence in a 3.1 does not mean an outside body. The manufacturer’s authorised inspection representative is independent of the manufacturing department, but that representative is employed by the manufacturer. A separate inspection company is a different situation entirely. When you compare quotations, ask who signs, in what capacity, and under whose quality system, rather than comparing certificate labels.
What ASME asks for instead
The ASME system is a separate framework, and its general requirements volume is explicit about what a mill must supply. The certifying organisation furnishes a certificate of compliance stating that the product was manufactured, sampled, tested and inspected in accordance with the specification, including year-date, the supplementary requirements, and any other requirements designated in the purchase order or contract, and has been found to meet those requirements.
| Point | ASME requirement in the general requirements volume | Practical consequence for a buyer |
|---|---|---|
| Signature | A signature or notarization is not required; the document must be dated and must clearly identify the organisation submitting it | An unsigned certificate is not automatically invalid. Check the identity of the issuing organisation, not the presence of a signature |
| Responsibility | Notwithstanding the absence of a signature or notarization, the certifying organisation is responsible for the contents of the document | The certificate carries legal weight without a signature. Ask who issued it |
| Test report content | Heat number, heat analysis, product analysis if specified, tensile properties, gauge length where strip specimens were used, bend test, flattening test, hydrostatic test pressure, nondestructive electric test method, impact test results, and any other results the product specification requires | Request the test report separately; it is a distinct document from the certificate of compliance |
| Supplementary requirements | Results required by supplementary requirements must be reported, but may be reported in a separate document | Do not assume the certificate of compliance is the complete record. Ask which results travel separately |
| Incomplete orders | The test report must explain the letter added to the specification number on the material when not all specification requirements have been completed, and the purchaser must certify completion before the letter is removed | Always check the specification suffix on the certificate against the marking on the pipe |
| Electronic transmission | A certificate, test report or similar document printed from or used in electronic form from an EDI transmission has the same validity as a printed counterpart | An emailed PDF is acceptable as a document. The content still has to meet the invoked standard |
The material specification adds its own certification layer on top of this. For austenitic stainless pipe, the certification must state whether or not the material was hydrostatically tested, and if the material was non-destructively tested, the certification must say so, name the standard practice that was followed, and state what reference discontinuities were used. For forgings, the general requirements for the product specification add a further marking layer: the specification number, grade or marking symbol, class, the certifying organisation’s name or symbol, the heat number or heat identification, size and, where applicable, the service rating, with the Standard Marking System of MSS SP 25 to be followed except that the word steel is not to be substituted for the specification grade.
This is where the certificate and the marking have to agree with each other. The 316L stainless steel pipe listing and the Incoloy 825 seamless pipe are supplied with the heat number, specification number and grade marked on each length, and those markings are what a receiver checks against the certificate. A certificate that does not carry the heat number of the material in front of you is not a document you can use for traceability, whatever type it is.
A receiving checklist
Before material is released for fabrication, five questions settle most of the risk. Is the certificate type the one the order actually requires, written as 2.1, 2.2, 3.1 or 3.2, rather than the vague phrase mill test certificate? If it is a 3.2, is the second validating party named and accepted, and was that arranged before the purchase order was placed? Does the document carry specific inspection results for your heat or test unit, with the heat number matching the marking on the material? Are the supplementary results the order called up present, and if they sit in a separate document, has that document actually arrived? And does the certificate explain any letter added to the specification number, and is the suffix on the pipe consistent with it?
On the ASME side, add one more: does the certification state whether the material was hydrostatically tested, and if it was non-destructively tested, which practice was used and against what reference discontinuities.
Send us the material, the size range and the test package you need, and tell us which certificate type your order calls up. We will quote against the governing product specification and state exactly what documentation travels with the material, so the certificate that arrives matches the certificate you ordered.
Speak to our technical sales desk on WhatsApp and telephone +86 186 2137 7760, or through our contact page, for the material and certification package for your next order.
