EVALUATION OF LIQUID PENETRANT SYSTEMS

This paper discusses an evaluation carried out by the Canadian Forces for the selection of penetrant processes. Most of the evaluation measured the systems' response to defects of a fatique nature. Also, reviewed are the effects of residual entrapped penetrants. Various inspections to critical aircraft components have necessitated selection of high-sensitivity penetrant systems either for in-shop or in-situ use. In realizing the difficulty of comparing products, reference standards containing fine fatigue defects on both smooth and peened surfaces were selected to present a similar degree of inspection difficulty as the field application. Tests carried out by two evaluation bodies show similar results when reviewing fluorescent penetrants employing the water-washable, post-emulsified and solvent methods of excess penetrant removal. The results of the tests carried out show an extensive sensitivity difference between products tested as some of the general purpose penetrants provided a more capable examination than the high-sensitivity penetrants. A need to monitor defect progression led to the evaluation of the effects of residual entrapped penetrants. The results of these tests have proven the necessity of strict observance to pre- and post-cleaning operations as repetitive inspections produce greatly reduced indications, particularly when a color contrast method is used in the field prior to a fluorescent inspection at overhaul.

  • Availability:
  • Supplemental Notes:
    • Presented at the National Fall Conference of the American Society for Nondestructive Testing, October 21-24, 1974, in Detroit, Michigan.
  • Corporate Authors:

    National Association of Corrosion Engineers

    P.O. Box 1499
    Houston, TX  United States  77001
  • Authors:
    • Nielson, D C
    • Thomson, JGH
  • Publication Date: 1975-12

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Filing Info

  • Accession Number: 00129387
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Apr 21 1976 12:00AM