First check identity and traceability

Start at the top of the document. Confirm the legal manufacturer, certificate number, issue date, purchaser, PO number and item number. The product description should agree with the order: ASTM A182 cấp, ASME standard, NPS, lớp học, loại mặt bích, facing and quantity.

The heat number on the certificate must match the permanent flange marking and packing list. If components were split, re-marked or processed by another organization, review the traceability chain and any endorsed copies. A technically correct certificate that cannot be linked to the physical flange is not sufficient evidence.

Review chemistry, heat treatment and mechanical results

For F91 and other heat-treatment-sensitive grades, the relationship between chemistry, thermal history, mechanical properties and hardness deserves close attention. PMI alone cannot close that review.

Check supplementary testing and declarations

Compare the certificate with the material requisition and inspection plan. If the order requires PMI, UT, magnetic-particle examination, thử nghiệm tác động, grain size, corrosion testing or third-party witnessing, the MTC or attached reports should identify the results and traceable report numbers.

EN 10204 Kiểu 3.1 is commonly requested for metallic products. It defines an inspection document validated by the manufacturer’s authorized inspection representative independent of manufacturing. It does not decide which chemistry, hardness or NDE requirements apply; those come from the product standard and purchase order.

Ten-point MTC approval checklist

1. Manufacturer and manufacturing location are identified.
2. PO, item, quantity and product description match.
3. Specification edition and exact ASTM A182 grade are correct.
4. Heat number matches the flange and packing records.
5. Chemical analysis includes required actual values.
6. Heat treatment matches the ordered grade and condition.
7. Mechanical and hardness results meet the applicable limits.
8. Supplementary tests and NDE match the order.
9. Deviations, retests and repairs are disclosed and approved.
10. The document is validated by the appropriate authorized representative.

Resolve discrepancies before release or installation. Do not edit a supplier certificate locally to make it match; request a controlled correction from the issuing organization.