EN 10204 3.1 vs 3.2 certificate explained for EN 1092-1 flanges — TheSupplier

EN 10204 3.1 vs 3.2 Certificate Explained for EN 1092-1 Flanges | TheSupplier

By thesupplier • August 27, 2025 • 4 min read

What EU buyers must know about material test certificates (MTCs), compliance, and third-party inspection for EN 1092-1 flanges.

📘 What you’ll learn:

  • ✅ What EN 10204 certificates are and why they matter in Europe
  • 📑 Key differences between 3.1 and 3.2 certificates
  • 🔍 When EU buyers must insist on a 3.2 with third-party witness
  • ⚡ How to order EN 1092-1 flanges with correct certification

In Europe, every EN 1092-1 flange must ship with a valid EN 10204 Material Test Certificate (MTC). These certificates ensure traceability and compliance with EU directives, and are often checked during plant audits. The most common are EN 10204 3.1 and EN 10204 3.2.

💡 Definition: EN 10204 defines different inspection documents for metallic products. 3.1 = manufacturer’s QA cert. 3.2 = same tests, but signed by both manufacturer and an independent third-party.

3.1 vs 3.2 Certificates — What’s the Difference?

AspectEN 10204 3.1EN 10204 3.2
Issued byManufacturer’s QA deptManufacturer + Independent Inspector (TÜV, Lloyd’s, SGS, DNV)
VerificationBased on manufacturer’s test resultsIndependent witness verifies test results and stamping
Cost & lead timeStandard, included in most ordersHigher cost & longer lead time (due to 3rd-party scheduling)
When requiredGeneral industry, non-critical linesPressure vessels, oil & gas, nuclear, regulated industries

When Should EU Buyers Ask for 3.2?

Not every order needs a 3.2. But in certain sectors, it is mandatory:

  • ✔ Pressure equipment under PED 2014/68/EU
  • ✔ Oil & gas refineries, offshore platforms
  • ✔ Nuclear or critical safety lines
  • ✔ Projects where third-party insurance requires independent certification

Need EN 10204 3.1 or 3.2 certified flanges with DDP delivery?

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Checklist for Buyers

📝 Always include in your PO:

  • PN rating (e.g. PN16, PN40)
  • Flange type (slip-on, weld neck, blind, etc.)
  • Material grade (316L, Duplex 2205, P245GH, etc.)
  • Certificate required: EN 10204 3.1 or 3.2

Conclusion

Both EN 10204 3.1 and 3.2 ensure compliance, but the level of assurance differs. If your project involves pressure vessels or regulated industries, request a 3.2 certificate. For standard industry supply, 3.1 is sufficient.

See our Europe flange page or request a certified quote now.