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Nil Khosol Co., Ltd. is an engineering company providing fabrication, installation, repair and maintenance

 Quality assurance
Quality control section works hand in hand with various fabrication teams in the factory and the project engineer.

The quality control officer participates in the preparation of the quotation and bidding for the project. Once a project is awarded, all parties concerned start working together closely. All the related document, information and data are shared or sent to everyone in the project in the timely manner.

General inspection plan
Below is the general inspection and test plan for a vessel manufacturing. Each inspection point must be passed. If not, there will be re-work or repairing that also may need client's approval.
  •  Design and engineering
    (require client's approval)
  •  Shop drawings
    (require client's approval)
  •  Manufacturing manual or procedure
    (require client's approval)
  •  Materials procurement
    (inspection - mill test report, physical and chemical, thickness, lamination)
  •  Marking off
    (inspection - dimension)
  •  Cutting
    (inspection - dimension, edge preparation, locations of nozzles, etc.)
  •  Forming, machining, drilling
    (inspection - dimension, curve, locations of holes, etc.)
  •  Shell and heads assembly
    (inspection - dimension, orientation)
  •  Welding
    (WPS, PQR, WQT, inspection, submission document to client if required)
  •  Nozzle opening and support fixing
    (inspection - dimension)
  •  Welding
    (WPS, PQR, WQT, inspection, submission document to client if required)
  •  Post weld heat treatment
    (inspection - temperature rate, holding duration)
  •  Hydrostatic test
    (inspection - test pressure, holding time, leakage)
  •  Cleaning, surface preparation and coating
    (inspection - surface, film thickness, color)
  •  Packing
    (inspection - method of packing, protection, marking, packing list)
  •  Transportation
    (inspection - protection, safety, delivery document)
  •  Delivery to client
Details in an inspection plan
The inspection plan will contain:
  •  Date and revision number
  •  Name of the project
  •  Job number or project number
  •  Client name
  •  Equipment or part to be inspected
  •  Drawing number, revision number and other related document
  •  Description of the inspection
  •  Applicable industrial code
  •  Names of parties to witness and take part in the inspection
  •  Acceptance criteria
  •  Inspection schedule (which reflects the overall manufacturing schedule)


Non-conformance report
If an inspection is not passed, or there is a problem during the manufacturing, prompt action is taken. Non-conformance report is prepared and sent to the higher level staff (quality officer, project engineer, plant manager and the top management). On the job discussion is held to find a solution. The method of solving the problem or the change of design (if necessary) shall be submitted to the client for approval before starting the repair or re-work.

The non-conformance report will contain:
  •  Date and report number
  •  Name of the project
  •  Job number or project number
  •  Client name
  •  Part name, part number, serial number, quantity
  •  Drawing number, revision number and other related document
  •  Non-conformity description
  •  Disposition, conclusion and approval