Valve Documentation Requirements for Oil & Gas — MTCs, Test Certs, TPI & Traceability

In oil and gas valve procurement, the physical valve is only half the delivery — the documentation package is equally important. Inspectors at major operators like Aramco, Shell, and Equinor regularly reject valve deliveries not for dimensional or pressure issues, but for incomplete, incorrect, or non-compliant documentation. Understanding what each document certifies — and when it's required — is essential for efficient procurement and delivery.

EN 10204 Material Test Certificates (MTCs)

• EN 10204 2.1 (Manufacturer's Declaration): Confirms material meets specification without test data — not acceptable for oil & gas
• EN 10204 2.2 (Test Report): Manufacturer's own test data, not witnessed — acceptable for low-criticality utility valves only
• EN 10204 3.1 (Inspection Certificate 3.1): Third-party witnessed test data from manufacturer's quality representative (QR) — standard for all oil and gas valves
• EN 10204 3.2 (Inspection Certificate 3.2): Third-party test data witnessed by an independent, accredited inspection body AND the purchaser's representative — required for critical or NACE-service valves
• Content: Material heat/lot number, chemical composition (per ASTM/ASME spec), mechanical properties (yield, tensile, elongation, hardness, Charpy impact if required)

API 598 Pressure Test Certificate

API 598 (Valve Inspection and Testing) specifies: shell (hydrostatic body) test at 1.5× rated cold working pressure; seat leakage test at rated cold working pressure; backseat test (where applicable). The API 598 test certificate records: valve identification, test pressure applied, test duration, test fluid (typically water for hydrostatic or air/gas for low-pressure seat test), leakage measurement, and pass/fail result. Required for: all oil and gas service valves; all API 6D and API 600 valves; all ASME B16.34 valves.

PMI — Positive Material Identification

PMI (Positive Material Identification) uses a handheld XRF (X-ray fluorescence) analyser to verify the elemental composition of valve bodies, trim, and fasteners actually received — confirming they match the specified material grade. PMI is required by most major operators on alloy steel (Cr-Mo: WC6, WC9, F22, F91), stainless steel (SS 316, Duplex, Super Duplex), and nickel alloy (Hastelloy, Inconel) valves. PMI is NOT required for plain carbon steel (A216 WCB, A105) by most specifications, though some critical valve lists include it. PMI reports include: valve identification, element percentages measured, specified range, pass/fail.

NACE MR0175 Compliance Certificate

NACE MR0175/ISO 15156 (Petroleum and Natural Gas Industries — Materials for Use in H₂S-Containing Environments) specifies material hardness limits, heat treatment requirements, and alloy restrictions for valves in sour service. A NACE MR0175 compliance certificate from the valve manufacturer confirms: (1) body material maximum hardness (e.g., A216 WCB ≤ 22 HRC; A182 F316 ≤ 22 HRC per MR0175); (2) all hardness testing results per individual heat; (3) confirmation of applicable Environmental Limits (Region 1/2/3 of ISO 15156-2) and Material Qualification.

Third-Party Inspection (TPI) Reports

Many operators require third-party inspection at the valve manufacturer's facility before shipment. Common TPI agencies: Bureau Veritas (BV), SGS, Intertek, TÜV Rheinland, DNV GL, and the operator's own inspectors (Shell QAQC, Aramco inspector). TPI reports cover: material receiving inspection (MTCs vs. purchase order spec); dimensional inspection per drawing; pressure testing (witnessed API 598 test); visual and surface inspection; packing and shipping inspection. TPI reports are required for: all NACE MR0175 sour service valves; Class 600+ valves for critical service; any valve on the operator's critical valve list (CVL).