What Does an EN 10204 3.1 Certificate Prove on a Ball Valve?
Key Takeaway
An EN 10204 3.1 certificate is a document in which the manufacturer reports test results for the lot actually delivered, validated by a person independent of the manufacturing department. It shows what a casting or bar was when it was made. It does not show that the valve in the carton was built from that lot, and it is not a third-party check. Before accepting one, ask which parts it covers, how each valve is tied to a heat number, and who signed it.
What are the four EN 10204 document types?
EN 10204 defines four kinds of inspection document, and what separates them is who validates the document and whether the results come from the lot being delivered. The standard is published by CEN, the European standards body. This article was written from published summaries of the 2004 edition, not from a licensed copy of the standard, and the sources note at the end says so again.
| Type | What the manufacturer provides | Test results | Who validates |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | None | The manufacturer |
| 2.2 | Test report, with the manufacturer declaring compliance | Yes, from non-specific inspection | The manufacturer |
| 3.1 | Inspection certificate | Yes, from specific inspection | The manufacturer’s authorised inspection representative, independent of the manufacturing department |
| 3.2 | Inspection certificate | Yes, from specific inspection | That same independent representative, plus either the purchaser’s representative or an inspector designated by official regulations |
The summaries read describe non-specific inspection as tests on products of the same grade, not necessarily on the heat or lot being delivered, and specific inspection as tests on the delivered product, traceable to its heat and lot. That difference is why a 2.2 and a 3.1 are not interchangeable. A 3.1 is also still a document the manufacturer writes about its own product. The independence is that of one person from the production department, not of the company from its customer.
What does a 3.1 certificate certify on a ball valve?
Only what the order or the product specification told the manufacturer to test. One of the summaries states that the test unit and the tests come from the product specification, the regulations or the order. So 3.1 names a kind of document, not a list of tests. On a ball valve it can be attached to two different kinds of result:
- Material results for a part. The grade, the heat number, the chemical composition and the mechanical properties of the body, ball, stem or end connection.
- Test results for the valve. For example a shell test or a seat leakage test, with the pressure and the result.
A certificate that says 3.1 but lists only a material grade says nothing about leakage, and a leakage report is not a material certificate. Write each into the order by name. What each leakage test shows is covered in API 598 Is Three Tests, and Only One Is About Shut-Off, and the chemistry limits to compare against belong to the grade’s own specification, as discussed in Is CF8M the Same as 316?
What does a 3.1 certificate not prove?
Four things are easy to assume and are not in the document.
- That this valve contains that lot. The certificate describes a heat or lot. The link from the lot to one valve is a separate matter, covered in the next section.
- That anyone outside the manufacturer checked. The 3.1 validator belongs to the manufacturer, only to a different department. A 3.2 adds the purchaser’s representative or an inspector designated by official regulations.
- That the valve works. Unless pressure or leakage tests are listed on it, a material certificate does not speak to them.
- That the casting is sound. Chemistry and strength describe the metal. Whether a particular casting has shrinkage or gas porosity is a different question, covered in What Casting Quality Does to a Ball Valve.
How does a certificate get tied to one valve?
Through the heat number, and the tie is often made by hand. A Valve World Americas article of April 2026 describes the problem in pharmaceutical projects. Each valve has several wetted components, each with its own heat number and certificate, and matching them to the buyer’s tag numbers takes manual effort. Tracking relies on spreadsheets and on physical tags that can be lost or damaged during welding, and valves are often quarantined on arrival when the supplier’s reference numbers and the buyer’s tag numbers do not match. The author works for a valve manufacturer that sells a digital solution, so the remedy is a vendor view. The mechanics, however, apply to any buyer.
The third box is the one to ask about. Three questions cover it:
- Is the heat number cast in or stamped on each part, so that it can be read on a valve taken from the lot?
- Is the heat number recorded against the valve’s serial number or lot number?
- If the body casting is bought in, whose certificate covers it, the foundry’s or the valve maker’s?
The last one also connects to where the casting comes from. If it moves to another foundry, the certificates move with it, which is one reason a change of casting source belongs in the re-qualification described in Changing Valve Supplier: What Has to Be Re-Qualified.
How do you read a 3.1 certificate?
In six checks, none of which needs a laboratory.
- Match the grade to the order. The grade named on the certificate must be the grade on the drawing or purchase order, for example the cast grade CF8M under ASTM A351 for a cast stainless body.
- Find the heat numbers and look for them on the parts. A number that cannot be found on any part cannot be tied to the valve.
- Compare the results with the grade. Chemistry and mechanical values are checked against the limits of the specification the certificate names, not against a number from memory.
- Check which parts are covered. A set that covers the body only leaves the ball and the stem unaccounted for.
- Read the signature block. A name, a position and a date should be there, and the position should sit outside production.
- Check what it is attached to. The order number, and a valve or lot number, should appear, and the manufacturer named should be the one that made the material, not only the one that sent it.
When is a 3.2 certificate worth asking for?
When the buyer needs someone outside the manufacturer to stand behind the results. A 3.2 carries the signature of the manufacturer’s independent representative and of either the purchaser’s representative or an inspector designated by official regulations. It adds a party, so it adds scheduling and cost. The summaries read give no figures and this article does not invent any. The usual reason to ask is that a project specification or a regulation names it.
A 3.2 is not a substitute for checking the goods. Lot inspection by sampling is a separate step, described in How Do You Inspect a Lot of Stainless Steel Ball Valves Before It Ships?, and the first lots from a new supplier are what sample approval is for.
What should the order say about certificates?
It should name the document, the parts, the link to the valve and the timing. The wording below is a starting point for an order or an RFQ, to be adapted to the standards the project uses.
| Wording in the order | What it secures |
|---|---|
| Material certificates to EN 10204 3.1 for body, ball, stem and end connections | Results for a named lot of each named part, with heat numbers |
| Heat number marked on each part and recorded against the valve serial number | The link from certificate to valve |
| Valve test report stating the test standard, the pressures and the result per valve or lot | Leakage results, kept separate from material results |
| Certificates listed on the packing list, copies sent before shipment | Time to check them before the goods arrive |
| Notice before the casting source or the material supplier changes | The certificate set stays matched to what is shipped |
Certificates also sit alongside the supplier’s own quality system papers. What an ISO 9001 certificate does and does not cover is a different question, discussed in What Does a Valve Manufacturer’s Certification Actually Prove?
Frequently asked questions
What is an EN 10204 3.1 certificate?
It is an inspection certificate in which the manufacturer reports test results for the lot delivered. A person authorised by the manufacturer and independent of the manufacturing department validates it. The tests it reports come from the product specification, the regulations or the order.
What is the difference between 3.1 and 2.2?
A 2.2 reports results from non-specific inspection, tests on products of the same grade that are not necessarily from the heat or lot delivered. A 3.1 reports results from specific inspection of the delivered lot and is validated by a person independent of the manufacturing department.
Is a 3.1 certificate a third-party document?
No. The manufacturer issues it, and the validator is the manufacturer’s representative from outside the production department. A third party enters with a 3.2 certificate.
What is the difference between 3.1 and 3.2?
A 3.2 is signed by the manufacturer’s independent representative and also by the purchaser’s representative or an inspector designated by official regulations. A 3.1 carries only the manufacturer’s signature.
Does a 3.1 certificate prove that a ball valve passed a pressure test?
Only if the certificate lists pressure or leakage tests. A material certificate reports grade, chemistry and mechanical properties. The valve test report is a separate document and should be asked for by name.
What is a heat number and why does it matter on a valve?
It identifies the melt the metal came from, and the certificate reports its results against that number. Seeing the same number on the part is what ties the part to the certificate.
What should a buyer write in an order to get a 3.1 certificate?
The document type, the parts it must cover, the heat number marking and its record against the valve serial number, a separate valve test report, and notice before the material source changes.
Related Articles
- What Casting Quality Does to a Ball Valve: Porosity, Inclusions and Field Failure
- Is CF8M the Same as 316? What Changes When a Ball Valve Body Is Cast
- API 598 Is Three Tests, and Only One Is About Shut-Off
- How Do You Approve a Stainless Steel Ball Valve Sample From a New Supplier?
- How Do You Inspect a Lot of Stainless Steel Ball Valves Before It Ships?
- What Should You Check When You Audit a Ball Valve Factory?
- What Does a Valve Manufacturer’s Certification Actually Prove?
- What Does Made in Taiwan Mean on a Stainless Steel Ball Valve?
- Changing Valve Supplier: What Has to Be Re-Qualified
- Stainless Steel Ball Valve OEM Manufacturer in Taiwan
Referenced sources: Van Leeuwen, EN 10204 inspection documents, Projectmaterials, EN 10204 2.1 vs 2.2 vs 3.1 vs 3.2 and Valve World Americas, Effective Product Traceability Across the Valve Industry (16 April 2026).
EN 10204:2004 itself is a licensed CEN standard and was not read for this article. The document definitions above follow two published summaries that agree with each other, and the wording of any clause should be checked against a licensed copy before it goes into a contract. The Valve World Americas article is written by an employee of a valve manufacturer and is cited for the problem it describes, not for the product it proposes. No test figures or limits for any alloy are given here, because none were read from the specifications themselves.