EN 10204 is the European standard that defines the types of material test documents required when buying metallic products. Types 3.1 and 3.2 are the inspection certificates used in oil and gas — they differ in who signs them, not what they test. Here is what every Aramco contractor needs to know.
EN 10204 — formally titled Metallic Products — Types of Inspection Documents — is a European standard published by CEN (the European Committee for Standardization) that defines the format, content, and validation requirements for material test documents supplied alongside metallic products.
Although it is a European standard, EN 10204 has been adopted globally by the oil and gas, petrochemical, power generation, and construction industries as the default framework for specifying what kind of material documentation buyers require from their suppliers. Saudi Aramco, ADNOC, QatarEnergy, and virtually every major EPC contractor reference EN 10204 document types in their Purchase Orders and engineering specifications.
The standard defines four document types — 2.1, 2.2, 3.1, and 3.2 — that differ progressively in the specificity of testing performed and the independence of the party who validates the results. Understanding which type your Purchase Order requires is essential: specifying 2.2 when Aramco requires 3.1 will result in document rejection at Goods Receipt inspection.
EN 10204 is the European standard defining four types of metallic material inspection documents. The key distinction is not whether the material meets specification, but the independence and traceability of the test evidence: Types 2.1 and 2.2 use non-specific (representative) test data; Types 3.1 and 3.2 tie all test data to the heat number of the exact delivered batch. Saudi Aramco requires Type 3.1 at minimum for all SAEP-347 stockist materials.
EN 10204 types define who validates the test results and how specifically the testing is tied to the delivered batch — not whether the material meets the specification. A 2.2 and a 3.2 certificate may report the same chemical composition values; the difference is the chain of custody and independence of the validator.
EN 10204 organises material test documents into two categories — non-specific inspection and specific inspection — each with two sub-types:
A statement by the manufacturer that the product meets the requirements of the order — no test results, no heat data. Issued by any authorized representative of the manufacturer. Not accepted in oil & gas for critical materials.
A document stating compliance, accompanied by actual test data — but the data may come from tests on representative samples of the same product type, not necessarily from the specific batch delivered. Issued by any authorized manufacturer representative. Rarely accepted for Aramco.
A document issued by the manufacturer's own authorized inspector — who is independent of the production department — based on tests carried out on the specific batch of material being delivered. Heat number links the certificate directly to the product. Standard requirement for SAEP-347 materials.
A 3.1 certificate that is additionally countersigned by the purchaser's own representative or a third-party inspector nominated by the purchaser. Both parties must be present at the time of testing or witness the results. Required for sour service, H₂S-rated, and other safety-critical Aramco materials.
EN 10204 defines four document types in two categories. Types 2.1 (Declaration of Compliance) and 2.2 (Test Report) are non-specific — test data may come from representative samples, not the exact delivered batch. Types 3.1 (Inspection Certificate) and 3.2 (independently witnessed) are specific — all test data is tied to the heat number of the delivered material. For Saudi Aramco SAEP-347 materials, Type 3.1 is the minimum standard; Type 3.2 is required for sour service and H₂S-rated applications.
| Criterion | Type 3.1 | Type 3.2 |
|---|---|---|
| Who issues it? | Manufacturer's authorized inspector (independent of production dept.) | Manufacturer's authorized inspector AND purchaser's representative or nominated TPI |
| Is test data batch-specific? | Yes — tied to the heat/lot number of the delivered material | Yes — same as 3.1, plus independently witnessed |
| Third-party witness required? | No — internal independent inspector only | Yes — purchaser rep or external TPI must countersign |
| When does Aramco require it? | Standard SAEP-347 stockist materials — valves, fittings, flanges, pipe | Sour service materials (H₂S), SAES-L-108, SAES-L-133, critical pressure vessel components |
| Typical lead time impact | Minimal — issued at mill during normal production | Adds 3–10 working days for TPI scheduling and witness inspection |
| Can a stockist issue it? | No — must originate from the manufacturer | No — stockist passes through original mill certificate |
The critical difference between EN 10204 Type 3.1 and Type 3.2 is the second signature: a 3.1 certificate is issued by the manufacturer's authorized inspector (independent of production); a 3.2 certificate additionally requires countersignature by the purchaser's representative or a nominated third-party inspector (TPI) who witnesses the testing. Type 3.2 typically adds 3–10 working days for TPI scheduling. Neither type can be issued by a stockist — both must originate from the original manufacturer.
Saudi Aramco does not apply a single EN 10204 type across all materials. The requirement depends on the service conditions defined in the applicable SAES (Saudi Aramco Engineering Standard) and the specific Purchase Order. The table below covers the most common scenarios encountered by contractors and stockists:
Applies to the majority of SAEP-347 stockist materials for standard utility and process service — carbon steel pipes with EN 10204 3.1 certification, fittings, flanges, and valves per SAES-L-108 Class Normal service conditions.
Required for materials entering H₂S-containing or sour service environments per SAES-L-133 and SAES-A-206, or where the Purchase Order explicitly mandates TPI witness inspection.
The Purchase Order is always the definitive document. Aramco's project teams may specify 3.2 even for materials that don't technically require it under the applicable SAES, based on project risk assessments or contract terms.
When in doubt, request clarification from the Aramco Procurement representative before placing your order with your stockist — upgrading from 3.1 to 3.2 after order placement typically adds cost and time.
Positive Material Identification (PMI) is a non-destructive testing technique — typically X-ray fluorescence (XRF) or optical emission spectrometry (OES) — applied directly to delivered material to verify that the actual chemical composition matches the marked grade. PMI is a physical test performed on the specific pipe, fitting, or valve in the shipment. It is not a document review; it is a material verification.
SAEP-1142 mandates PMI on alloy steel and stainless steel materials — specifically where substituting a lower-grade material for a higher-grade alloy would create a safety risk. In practice, Aramco requires PMI for: austenitic stainless steels (ASTM A182 F316L, A351 CF8M), duplex and super duplex stainless steel, chrome-moly alloy steels (P11, P22, P91), and nickel alloy materials. PMI is generally not required for plain carbon steel (ASTM A105, A106, A234 WPB) — the appearance and MTC provide sufficient traceability. Check your Purchase Order: Aramco project teams may specify PMI on carbon steel for high-consequence or sour service applications.
The EN 10204 3.1 MTC is a document issued by the manufacturer at the time of production, certifying the chemical and mechanical properties of the heat. PMI is a real-time test applied at the point of delivery — it physically verifies that the material in front of the inspector matches the chemistry stated in the MTC. An MTC alone cannot confirm that a fitting stamped '316L' is actually 316L; PMI closes that verification gap. For Saudi Aramco projects, the MTC establishes the documented traceability chain; PMI provides the physical confirmation at goods receipt. Gulf Union Ozone offers PMI testing on request for all alloy and stainless steel orders — results delivered with the shipment documentation package.
Saudi Aramco applies EN 10204 Type 3.1 for standard SAEP-347 stockist materials — carbon steel pipes (API 5L, ASTM A106), flanges (A105/A182), butt-weld fittings (A234 WPB), and valves per 04-SAMSS-035. Type 3.2 is required for sour service materials entering H₂S environments (SAES-L-133, SAES-A-206) and wherever the Purchase Order explicitly mandates TPI witness. Always check the PO: Aramco project teams may specify 3.2 for any material class based on project risk assessment.
Every EN 10204 3.1 MTC from a competent mill follows the same general structure. Knowing what to look for — and what to verify — prevents document rejection at Aramco Goods Receipt inspection:
Manufacturer name, address, and EN 10204 type declaration (the certificate must explicitly state "3.1" or "3.2"). Also lists the purchase order number, customer name, quantity, product description, and applicable standard (e.g., ASTM A106 Gr. B, API 5L Gr. X52). Verify the PO number matches your order.
The heat number (also called melt number or cast number) is the critical traceability link. It must match the heat number physically stamped or stencilled on the product. If the heat number on the material doesn't match the MTC, the traceability chain is broken and Aramco inspection will reject it.
Lists actual elemental percentages — C, Mn, Si, P, S, Cr, Ni, Mo, V, etc. — for the specific heat tested. Each value must fall within the limits specified by the applicable standard. For sour service materials, check Carbon Equivalent (CE) against the SAES-L-133 or NACE MR0175 limit.
Lists UTS (ultimate tensile strength), YS (yield strength), elongation %, and — for PSL2 or sour service — Charpy impact energy values. Verify each result meets the minimum (or maximum, for hardness) required by the applicable standard and any Aramco SAMSS supplementary requirements.
For Type 3.1, one authorized inspector signs — who must be explicitly identified as independent of production. For Type 3.2, a second signature appears from the purchaser's representative or the nominated TPI, together with their organization's stamp. An unsigned or insufficiently identified certificate does not meet EN 10204 requirements.
An EN 10204 3.1 MTC contains five critical elements to check: the header block (PO number, applicable standard, and explicit '3.1' declaration), the heat number (must match the physical marking on the delivered material — any mismatch breaks traceability and triggers Aramco rejection), the chemical composition table (actual elemental percentages for the specific heat), the mechanical properties table (UTS, YS, elongation, and Charpy impact for PSL2/sour grades), and the authorized inspector's signature with independent identification. An unsigned, insufficiently identified, or heat-number-mismatched MTC does not meet EN 10204 requirements.
Gulf Union Ozone Trading Co. sources materials exclusively from manufacturers who issue EN 10204 Type 3.1 inspection certificates as a standard. We do not stock materials with 2.2-only documentation for any product category covered by SAEP-347.
For every shipment, we provide: the original mill MTC at 3.1 level, a Gulf Union Ozone Certificate of Conformance linking the MTC to your purchase order, and a heat number cross-reference that confirms the MTC heat matches the physical marking on the material received into our Jeddah warehouse.
When 3.2 is specified — for sour service or critical service projects — we can coordinate TPI witness inspection at the mill prior to shipment to Saudi Arabia. Contact us at order placement stage so we can schedule the TPI inspector without delaying your delivery.
An EN 10204 mill test certificate (MTC) is a document that records the actual test results — chemical composition and mechanical properties — for a specific heat or batch of material, linked to the heat number stamped on the product. It proves the material meets the specified standard (ASTM, API, EN, etc.). The EN 10204 standard defines four document types (2.1, 2.2, 3.1, 3.2) that differ in who issues and validates the document.
EN 10204 Type 3.1 is an inspection certificate issued by the manufacturer's own authorized inspector, independent of the production department. Type 3.2 is issued and countersigned by both the manufacturer's authorized inspector AND a representative of the purchaser or an independent third-party inspector nominated by the purchaser. Type 3.2 provides an additional layer of verification because it requires a witness outside the manufacturer's organization to validate the test results.
A stockist cannot issue its own EN 10204 3.1 or 3.2 certificate — these must be issued by the original manufacturer. A stockist can pass through the original mill's 3.1 or 3.2 certificate from its stock alongside its own Certificate of Conformance (CoC). SAEP-347 requires stockists to maintain and transmit the original manufacturer's inspection documents. Gulf Union Ozone supplies original mill MTCs at EN 10204 3.1 level with every order.
No. Saudi Aramco requires EN 10204 Type 3.1 for the majority of SAEP-347 stockist materials — valves, pipe fittings, flanges, and standard piping. Type 3.2 (with independent third-party countersignature) is mandated for sour service materials under SAES-L-133, pressure vessel components under SAES-A-206, and specific projects where the Purchase Order explicitly requires TPI. Always check your applicable SAMSS, Piping Material Class (PMC) sheet, and the project PO before requesting 3.2.
An EN 10204 3.1 MTC contains actual measured test results — heat number, chemical analysis values, tensile/yield/impact results, heat treatment details, and dimensional check. It is issued by the manufacturer and is traceable to a specific production heat. A Certificate of Conformance (CoC) is a declaration — typically issued by the stockist — confirming that materials meet the specified standard and purchase order requirements. SAEP-347 requires both: the original mill 3.1 MTC for traceability, and a stockist CoC as the compliance declaration.
Yes, for materials sourced directly from mills where 3.2 MTCs can be arranged. We coordinate third-party inspection through SGS, Bureau Veritas (BV), and Lloyd's Register at the origin mill. This adds lead time and inspection costs. For in-stock items at our Jeddah warehouse, original 3.1 MTCs from the mill are available immediately. Advise your 3.2 requirement at the RFQ stage so we can schedule accordingly.
Send your material specifications, quantities, and delivery location. We confirm stock availability and issue your quotation within 4 business hours — with EN 10204 3.1 mill certificates included at no extra cost.