Third-Party Inspection RFP: SGS, BV, TUV, DNV, Intertek Compared

4. Marking audit. MSS SP-25 — manufacturer logo, heat number, grade, size, rating.

5. PMI. XRF for screening; OES required when carbon must be quantified (316 vs 316L). Per API 578 sample plan or 100%.

6. Hardness. Per ASTM E10 (Brinell) or E18 (Rockwell); UCI portable per ASTM A1038 for in-situ.

7. NDE witness. UT (ASTM A388 / A578), MT (ASTM E709), PT (ASTM E165 / E1417), RT (ASME V Art. 2). The TPI witnesses; they do not perform.

8. Hydrostatic test witness. ASME B31.3, 1.5 × design pressure, hold time per code.

9. Packing + load supervision. ISPM-15 mark verification, container photos, seal numbers.

SGS, BV, TÜV, DNV, Intertek — the buyer-relevant differences

SGS (founded 1878, HQ Geneva) is the largest TIC firm globally and has the densest China inspector network. Best for high-volume programs and multi-site coordination. Strong on commodity pipe and structural.

Bureau Veritas (BV) (founded 1828) is the go-to for marine and oil & gas classified work. Their inspectors are typically dual-qualified for class society work, useful when the same fittings will end up on a ship or offshore platform.

TÜV Rheinland / SÜD / NORD (German technical service organisations) are strongest in PED (EU Pressure Equipment Directive) certification. Pick TÜV when CE marking under PED 2014/68/EU is contractual.

DNV (Det Norske Veritas) is the leading classification society for offshore and energy. Use DNV when the fitting is for an offshore project, hydrogen service, or DNV-classed asset.

Intertek (130-year history, 40,000 employees in 100 countries) competes head-to-head with SGS in China and is often more flexible on small-batch inspection (1–2 days). Strong reporting templates.

Common buyer mistakes

• Choosing the cheapest TPI quote without checking which engineer is assigned to the visit.
• Not specifying the sample plan; "random sample" gets interpreted as 1 piece.
• Booking inspection on the planned ship date — leaving no time for re-inspection if defects appear.
• Forgetting to authorise hold points in writing — the inspector cannot stop a load without buyer authority.
• Mixing TPI with mill QC: the TPI witnesses, the mill performs.

Buyer checklist for the TPI RFP

• [ ] Scope of inspection points listed (visual, dimensional, NDE witness, hydro witness, PMI, hardness, packing)
• [ ] Sample plan stated (AQL or 100%)
• [ ] Acceptance standards named for each test
• [ ] Hold points and witness points clearly distinguished
• [ ] Inspector qualification minimums (CSWIP / ASNT II) requested
• [ ] Reporting template requirement (24/48 h after visit)
• [ ] Re-inspection policy and rate stated
• [ ] Mobilisation lead time confirmed (typically 3–7 working days)

Sample RFP clause

"Quote per visit, not per day. Confirm CSWIP 3.1 or ASNT-TC-1A Level II inspector. Include cost of one re-inspection if rejection rate exceeds 5%. Issue preliminary inspection report within 24 hours of visit, signed final report within 5 working days. Buyer reserves the right to extend inspection a second day at the quoted day rate without re-mobilisation."

See how our certificates library lists prior TPI reports for seamless butt-welding pipe fittings and forged flanges and non-standard forgings. Send the agency RFP via our inquiry portal and we will coordinate the visit window.

Sources

• SGS corporate profile: https://www.sgs.com/en
• Bureau Veritas company facts: https://www.bureauveritas.com/
• TÜV Rheinland services: https://www.tuv.com/
• DNV services: https://www.dnv.com/
• Intertek services: https://www.intertek.com/