When QatarEnergy, ADNOC, or Aramco request the document package of a Chinese supplier, the real problem begins at technical review, not at price. We see three documentation gaps recur on major Gulf EPC contracts when contracting Chinese fabricators.

1. Material certification: EN 10204 type 3.2 vs GB/T 13321

The Chinese fabricator issues a GB/T 13321 material certificate and treats it as equivalent to EN 10204 type 3.2. It is not.

The defining difference: EN 10204 type 3.2 requires the certificate to be signed by an inspector independent of the production department — typically an Authorized Inspector or third-party. GB/T 13321 certificates are signed by the same internal QA function inside the fabricator's organisation.

When a TPI body — Bureau Veritas, DNV, SGS, Intertek — reviews the document pack against Aramco SAEP-1153, ADNOC ESS, or QatarEnergy DEP equivalents, the GB/T 13321 certificate is rejected. The batch is held for re-certification or re-supply. Critical-path slip is typically 4 to 6 weeks, sometimes more if the heat number traceability is weak and a fresh melt is required.

The procurement-side fix: the PO to the Chinese supplier must specify EN 10204 type 3.2 explicitly, the supplier must confirm in writing it has the independent-validation chain in place, and the certificate must be reviewed before release of shipment. We run this as a hold point on every Gulf-bound order.

2. Pressure vessel spec equivalence: ASME VIII Div.1 / UNI EN 13445 vs GB/T 150

Unfired pressure vessels on Gulf LNG, refining, and petrochemical projects are typically specified to ASME VIII Div.1 (Aramco SAES standard practice) or UNI EN 13445 (some EU-led EPC packages). The Chinese fabricator works to GB/T 150. The deltas are concrete and they affect cost, schedule, and field acceptance:

• Default corrosion allowance. GB/T 150 accepts 1 mm as a default minimum. ASME VIII Div.1 in combination with most Aramco and ADNOC standards expects 3 mm minimum, sometimes more for sour service. Wall thickness on the as-built drawing changes accordingly.
• NDE coverage on longitudinal welds. GB/T 150 accepts 20% sample radiography for many Class B vessels. ASME VIII UW-11(a) requires 100% radiography or ultrasonic testing for Category A welds in Class A vessels at thickness greater than or equal to 32 mm. The cost difference at fabrication is significant.
• Post-weld heat treatment thresholds and hold times. GB/T 150 and ASME VIII Div.1 UW-40 do not align on the temperature thresholds and the soak duration for several material grades. Aramco SAES generally tracks ASME. A vessel built to GB/T 150 PWHT parameters may not be acceptable on the Saudi side without re-treatment, which is rarely possible without distortion.

The fix is documented equivalence work before fabrication starts, not after. The PQR (Procedure Qualification Record) and WPS (Welding Procedure Specification) must be reviewed against the contract spec, not just the local Chinese standard. We do this at PO drafting and again at the pre-fabrication kickoff.

3. Supplier prequalification and the in-shop ITP

ADNOC's supplier prequalification framework runs on seven dimensions, each carrying independent weight: ICV (in-country value / local content), financial standing, technical capability, HSE record, quality assurance, human resources, and historical performance. Aramco runs a comparable seven-section vendor pre-qualification. QatarEnergy uses its own equivalent.

The same documentary discipline must be present in the Chinese fabricator's in-shop Inspection and Test Plan. Specifically:

• Hold points vs Witness points vs Surveillance points must be distinguished and counter-signed. A hold point cannot be passed without the surveyor signing on site. A witness point allows the manufacturer to proceed if the surveyor is delayed. A surveillance point is a lower-tier verification. ITPs that conflate these categories will not survive a TPI review.
• Class surveyor signatures. For class-relevant work — DNV, ABS, BV, LR, CCS, KR — every hold point in the ITP must show the surveyor's reference number and visit date. Retroactive signatures are visible in audit and unacceptable.
• MTR / MTC traceability from melt to delivery. The Material Test Report (MTR, often used interchangeably with MTC, Mill Test Certificate) must trace each finished component back to its specific heat number, with the heat number stamped on the material before processing. The chain must be unbroken through forming, welding, NDE, PWHT, and final inspection.

Aligning the Chinese in-shop ITP to Aramco / ADNOC / QatarEnergy procurement-book expectations from day one — not after the first TPI visit — typically saves two months on the delivery schedule and prevents end-of-project document rejection.

What we do

Meritus Technology operates from Shanghai as your procurement representation in China for Gulf EPC contracts. We read the prime contract specifications with you (Aramco SAES / SAEP, ADNOC ESS, QatarEnergy DEP / DEM, Saudi Aramco PIDC where applicable), translate the contractual obligations into an enforceable purchase order to the Chinese supplier, supervise PQR / WPS / NDE / PWHT in the workshop, coordinate third-party inspection (DNV, ABS, BV, LR, SGS, Intertek), and deliver a document package that survives Gulf TPI review the first time it is presented.

If you are managing Chinese sourcing for a QatarEnergy LNG, TA'ZIZ, Aramco, or any major Gulf EPC contract, the conversation is worth a call.