Table of Contents

18.1 Scope
18.2 Definitions
18.3 Records
18.4 General
18.5 Summary of Commonly Used Non-destructive Examination Methods
18.6 Visual Inspection
18.7 Radiography (R.T.)
18.8 Magnetci Particle Inspection (M.T.)
18.9 Ultrasonice Inspection (U.T)
18.10 Liquid Penetrant Inspection (P.T.)
18.11 Vacuum Box
18.12 "Holiday" Detectors
18.13 Identification of Metals
18.14 Hardness Testing
18.15 Surface Temperature Inspection
18.16 Camera
18.17 Paint Thickness Gauge
18.18 References
18.19 Glossary of Terms

18.1 Scope

The purpose of this section is to outline the most commonly used methods of non-destructive examination (NDE) for the general information of Company personnel, in particular Construction Specialists and the Welding Engineer.

Certain NDE operations, in particular radiography and ultrasonic inspection, are carried out by specialist independent organizations. The latter may be engaged:

  • By the subcontractor carrying out the works to be examined, as part of his scope.
  • Directly by Company as an NDE subcontractor in his own right.

The second alternative may sometimes by obligatory to meet client and/or authorities requirements.

Whatever the contractual configuration, it is the responsibility of the Welding Engineer before NDE starts:

  • To review the qualifications of personnel who will carry out NDE operations and interpret the results.
  • To define with all parties how the project NDE requirements are to be met.

Once NDE is in hand, the Welding Engineer shall continuously review quality:

  • Of the works being examined (welding for pipework for example) through the NDE program.
  • Of the NDE operation itself.

Piping, structural steel and storage tank subcontracts usually include prefabrication done in shops on site or offsite. It is important that the quality systems are coherent covering both shop and field operations. Interfaces between all parties i.e. the subcontractor doing the works, the NDE organization, the Welding Engineer, the client and authority (where applicable) shall be clearly defined. This applies in particular concerning responsibility for review and interpretation of radiographs.

Subsequent sections 18.2 to 18.19 are in effect reminders of what is required. However, they are no substitute for reading and familiarizing oneself with the subcontract, requisitions, specifications, standards, codes and drawings. In case of conflict it is these project specific documents which prevail.

No standard forms are proposed, it being usual to use those of the organization(s) carry out the non-destructive testing and interpreting the results.

18.2 Definitions

Non-Destructive Examination (NDE) is any examination process that determines the quality of a specimen without destroying it, permitting examination of all articles and materials that are to be used. N.D.E. includes non-destructive testing.

Non-Destructive Testing, NDT, are specific non-destructive examination methods used to detect material discontinuities. Four methods of N.D.T. are currently in common use: magnetic particle, liquid penetrant, ultrasonic and radiographic.

18.3 Records

Non-destructive examination, testing and inspection records shall provide sufficient information about procedures and equipment to permit repetition of the inspection.

18.4 General

  • Detailed NDE methods, instructions, procedures, specifications etc., can be obtained from the relevant applicable codes, standards and accepted standard practices.
  • It is standard practice and often obligatory that N.D.T. and certainly special or advanced inspection methods and techniques are performed by qualified licensed operators and specialists. The same applies to interpretation of results.
  • For each NDT method and technique, the parties shall prior to execution agree to the following:
  1. Applicable code or standard
  2. Acceptance criteria
  3. Extent of testing
  4. Authority approval (if applicable)
  5. Special requirements (sensitivity, etc.)
  6. Repair of defects (after test results)

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