Third-Party Inspection (TPI) is independent verification against a defined PO and inspection plan. Book required mill witnesses before the relevant tests occur. A Kanpur stockyard check can verify material, marking, dimensions, and documents but cannot recreate a mill witness after the event.
What TPI is, and what it is not
TPI is independent inspection of the ordered lot against the PO, approved ITP, and product standard. It is not mill QA, not a BIS licence, and not automatically an IBR form.
A third-party inspector works for the purchaser or for an official regulation, not for the rolling mill production desk. ISO/IEC 17020:2012 describes inspection-body competence and impartiality, including Type A third-party bodies. The inspector examines the item against the contract, the product specification, and the agreed ITP.
TPI is not a substitute for the mill test certificate. The mill still issues chemistry and mechanical results. TPI adds witness, review, or release. EN 10204 Type 3.2 is a specific inspection certificate countersigned by an independent inspector. A generic Certificate of Conformity may be narrower than Type 3.2. Write the document you need.
TPI is not an IBR form unless the inspector is recognised for that exact duty and the applicable form is completed through the official route. Company letterhead alone does not create authority. Use Form III-A for steam pipes, III-B for tubes, and III-C for boiler mountings and fittings.
Use TPI when the tender, PO, inspection plan, purchaser, or applicable authority requires independent inspection. Do not add it automatically to ordinary stock orders whose approved document set already defines mill certification and receiving checks.
- TPI: independent witness, review, or release
- Not mill QA and not a BIS licence
- Type 3.2 is a defined EN 10204 document
- An IBR form needs the recognised authority for that exact duty
- Skip TPI only when the PO waives it in writing
What are the stages of a typical Third-Party Inspection?
Book TPI before the first contractual witness or hold point. The approved ITP must identify the location, material identity, document review, dimensions, sampling, tests, release authority, records, and required attendance; not every scope includes drilling samples or tensile-test witnessing.
1. Pre-Inspection Meeting: Confirm scope and standards.
2. Visual & Dimensional Check: Verify against P.O.
3. Witness Sampling: Cut chips for chemical analysis.
4. Witness Testing: Tensile, bend, impact tests.
5. Release: Issue Certificate (e.g., Certificate of Conformity).
The inspection and test plan should list hold points before the mill dates the heat. Chemical sampling is product or ladle sampling as the product standard requires, not a free choice on the day. Tensile, bend, and impact tests follow the product specification, not a generic shop list.
Dimensional checks use the pipe or tube standard on the order. Wall and OD limits for IS 1239 class pipe are not the same as ASTM A53, IS 3589, or DIN 2391 precision tube. The inspector should measure against that standard and the PO, not against a remembered percentage from another product.
- Booking: At PO stage
- Witness: Chemical Sampling
- Witness: Mechanical Testing
- Release: Certificate of Conformity (CoC)
Which TPI agencies are commonly used for steel inspection?
Purchasers may nominate SGS, Bureau Veritas, Lloyd's Register, TÜV, IRClass, RINA, DNV, or another competent body. The tender and required accreditation scope should control the choice.
SGS, Bureau Veritas, Lloyd's Register, TÜV, IRClass, RINA, and DNV are examples of inspection organisations buyers may encounter. A brand name alone does not prove that the office and inspector have the required scope.
Name the agency on the PO when the tender or purchaser requires one. If the tender says “TPI by purchaser”, state the agency in the nomination letter before the mill books the inspection. Do not rank agencies from marketing descriptions.
Ask for the inspection-body accreditation scope. ISO/IEC 17020 covers inspection bodies. ISO/IEC 17025 covers testing laboratories. A 17025 lab report is not the same document as a 17020 inspection release. For IBR, the inspector must be recognised for that duty, not merely globally branded.
- Match the agency to the tender or nomination
- Verify the office and inspector scope
- Keep inspection-body and laboratory accreditation distinct
How TPI, Type 3.2, and IBR forms differ
TPI is an activity. Type 3.2 is an EN 10204 inspection certificate with the specified validation. IBR Forms III-A, III-B, and III-C are component-specific regulatory forms. Order the records the controlling documents actually name.
EN 10204:2004 Type 3.1 is validated by the mill authorised inspection representative independent of manufacturing. Type 3.2 is validated by that mill representative and by the purchaser inspector or an inspector designated by official regulation. Both types report specific inspection results for the delivered lot.
A TPI visit can support Type 3.2 when the inspector signs that certificate. The same visit can instead issue only a Certificate of Conformity or an inspection report. Those papers are useful, but they are not Type 3.2 unless they meet EN 10204.
The IBR forms index assigns III-A to steam pipes, III-B to tubes, and III-C to boiler mountings and fittings. Confirm applicability and authorised sign-off. Do not treat Type 3.2, a generic inspection report, or another IBR form as an automatic substitute.
Write separate PO lines for the mill inspection certificate, independent validation, and IBR documentation when the governing project requires them. For other work, order only the evidence required by the approved specification and quality plan.
- Activity: TPI visit and ITP
- Document: name 3.1, 3.2, CoC, or the exact IBR form
- IBR: confirm the required form and authority path
- Purchase specification controls the inspection-document type
| Document | Who validates it | Test results | Typical Kanpur use |
|---|---|---|---|
| EN 10204 Type 2.2 | Manufacturer | Non-specific | Not a lot certificate |
| EN 10204 Type 3.1 | Mill authorised inspector | Specific to the lot | When the purchase specification accepts it |
| EN 10204 Type 3.2 | Mill plus independent inspector | Specific to the lot | Export, many pressure tenders |
| TPI Certificate of Conformity | Named TPI agency | As the ITP states | Only if the PO names this paper |
| Applicable IBR form | Recognised authority for the duty | As the IBR route states | III-A pipe, III-B tube, III-C mounting/fitting |
RFQ checklist for booking TPI
Name the product, tests, document, agency, hold points, and who pays. Book before the mill rolls the heat. A late nomination cannot witness a test that already happened.
Product line: standard, grade, NB or OD, wall or class, length, end finish, coating, and quantity. Inspection is meaningless if the mill offers a different class or grade than the drawing.
Document line: Type 3.1, Type 3.2, Certificate of Conformity, and/or the component-specific IBR form. Name the TPI or inspecting authority if required. If nomination is pending, record that dependency.
ITP line: visual, dimensional, marking, chemistry sample, tensile, bend, impact, hydrotest, NDE. Mark each as review, witness, or hold. Hydrotest pressure and hold time come from the product standard or the PO, not from a generic 1.5 times rule copied across products.
Commercial line: state who contracts with and pays the inspector, fee basis, travel, waiting, retest, cancellation, delivery, freight, legally applicable taxes, and dates. Obtain every term in the current quotation.
- Standard, grade, size, wall or class
- Certificate type and agency name
- Witness, review, and hold points
- Who pays and which quoted expenses apply
- Delivery, freight, taxes, availability, and date: current written quotation
Booking TPI for dispatch from Kanpur
Mill inspection happens at the producing works. Kanpur is a stockyard hold point for document match, marking, and quantity. Do not treat a Kanpur walk-around as mill Type 3.2.
For a Kanpur-origin order, identify the actual material location, inspection location, collection or delivery point, packing, carrier, freight, taxes, availability, and promised date in the current quotation. A regional service-area statement is not proof that the ordered lot or inspector is ready.
PWD and JJM contractors should follow the inspection agency and hold points named by the tender. Sugar-mill boiler tubes follow the applicable IBR inspection path. Hydraulic and printing-cylinder shops should specify the dimensional and material evidence their drawings require.
If the lot is already in Kanpur stock, a TPI agency can still check marking, OD, wall, length, and papers against the PO. That is a stock inspection. It cannot recreate mill witness of tensile or hydrotest. For those tests, book TPI at the mill on the next heat.
Use steel pipes Kanpur, MS ERW Kanpur, seamless Kanpur, and the Kanpur steel market page for local supply context. Send the ITP with the RFQ.
- Mill TPI: witness tests at the works
- Kanpur TPI: stock, marking, documents
- Required mill witness cannot be recreated by a stock inspection
- Name the agency on the PO
Common TPI mistakes on Indian pipe orders
The usual failures are late booking, the wrong document name, the wrong product standard, and an inspector who is not recognised for IBR.
Booking after rolling is the first failure. Specific inspection has to see the tests. A 3.2 request on a finished Kanpur bundle is too late for mill witness.
Calling every paper “TPI certificate” is the second failure. Write Type 3.2 or the exact component-specific IBR form when required. A short CoC is not automatically either.
Applying one wall tolerance to every product is the third failure. The inspector must use IS 1239 class tables, IS 3589, ASTM A53, or the precision-tube standard on the PO. Do not import a seamless mill offer of minus 0 plus 10 percent onto class pipe.
Using an inspector without the required IBR recognition is the fourth failure. A global brand does not replace the approval required for the named duty. Verify the applicable roster or authority record before the visit.
- Book TPI on the PO, before rolling
- Name 3.1, 3.2, CoC, or the exact IBR form
- Measure to the product standard on the PO
- Confirm IBR recognition for the exact form and duty
Key points for TPI on a Kanpur order
Book early, name the document, and keep mill witness separate from stockyard checks.
These five points repeat nothing new. They are the decision list for the purchaser who has already read the stages above.
- TPI is independent inspection, not mill QA and not a BIS licence
- Type 3.2 and component-specific IBR forms are named documents; a CoC is not automatically either
- Book the agency and ITP on the PO before the heat is tested
- Kanpur stock inspection cannot replace mill witness of tensile or hydrotest
- Allocate TPI cost and expenses in the quotation