Third Party Inspection for Steel Structure – Fabrication
When the Steel Structure material inspection carried out and result was satisfactory or non-conformities closed by remedial action, then Steel Structure manufacture will be authorised to start fabrication.
The third party Inspector checks following points on Steel Structure based on the inspection and test plan (ITP) which is already agreed between purchaser and Steel Structure manufacture.
The inspection scope is determined in ITP, some clients prefer to have stringent control and put the TPI inspector in more “hold points” in fabrication activities and some others may take lesser “hold points” and put TPI much more in the review document.
This depend to the inspection budget which client assign for inspection, much more inspection will have much more costs and less risks and conversely less more inspection will have less costs but more risks.
For more detail review Inspection and Test Plan for Steel Structure article. There is draft ITP in this article which I believe it is the best practice for Steel Structure inspection.
Third Party Inspection for Steel Structure – Welded Structure
The third party inspector controls following points while production continues:
- Cleanliness and fit up of weld preparation
- Tacking up welds of good appearance
- Welding process approved
- Welders properly qualified
- Test coupons compiled where necessary
- NDE procedures properly applied and approved
- Completed weld profiles are acceptable
If third party inspector is not in the hold or witness point in these stages, then will review steel structure quality control report in his coming visit or in final inspection day.
Third Party Inspection for Steel Structure – Bolted or Riveted Structures
The third party inspector controls following points while production continues:
- Dimensional check on pre-drilled parts
- Correct fastening being used
- Trial assembly of sub-structures
If third party inspector is not in the hold or witness point in these stages, then will review steel structure quality control report in his coming visit or in final inspection day.
Third Party Inspection for Steel Structure – Rust Prevention/Painting Inspection
After completion of all fabrication the painting process is started under supervision of third party inspector, the inspection is done based approved procedure.
Following points are taken in account while the structures are under painting process:
- Items have been prepared for coating as per specification requires
- Proper records of surface preparation and coating build up have been kept
- Paying particular attention to drying times/times between coats.
- Painted surfaces are free from drips, runs and bare areas.
- Dry film thickness measurements are checked.
If third party inspector is not in the hold or witness point in these stages, then will review steel structure quality control report in his coming visit or in final inspection day.
Third Party Inspection for Steel Structure – Final Inspection
A final random inspection on quantities and visual appearance is necessary to be done by third party inspector on finished materials.
Third Party Inspection for Steel Structure Packing, Marking and Shipping
The following points are checked by the third party inspector:
- Cleanliness of components
- Proper rust prevention for all machined surfaces
- Protection of protruding parts
- Shipping and other marks
Third Party Inspection for Steel Structure Documentation
When necessary the documentation package is reviewed and endorsed by the third party inspector.