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U.S. Department of Energy
Office of Scientific and Technical Information

Pre-inspection degreasing

Conference ·
OSTI ID:64639
 [1]
  1. Babb Co., Villepreux (France)
Degreasing is the process of removing contaminants from the part. Examples of contaminants are oxides, paint, scale, slag, oil, grease, water, etc. These contaminants can interfere with the subsequent penetrant inspection by either preventing the penetrant from entering the flaws, or by absorbing the penetrant on the surface and then producing either objectionable background levels, or even a ``false call``. Properly degreased parts will have no contaminants on the surface and no contaminants in the flaws. Degreasing operations can be broadly divided into two types: Shop degreasing, and Field degreasing. Shop degreasing is performed in fixed installations, and is usually associated with a production line penetrant inspection system. The degreasing operation takes place after the parts have been prepared by grinding, acid etching, neutralization, rinsing, drying, etc. Field degreasing is performed when a fixed installation is unavailable, when parts are too large to process in the fixed installation, or when the inspector is ``in the field`` and has only portable materials to work with. Field degreasing may also be done after some surface preparation, such as grinding. One might then ask, ``What is the ideal precleaning or degreasing solvent?`` The answer is that there is no single ideal solvent, except in fixed installations. But for other inspections, the main characteristics should be that it: meets contaminant specifications (halogens, sulfur, other elements); be efficient in removing oils, grease, and water (which requires that it contain both polar and non polar solvents); be volatile; and be composed of ingredients which present a low health hazard.
OSTI ID:
64639
Report Number(s):
CONF-931193--; ISBN 0-931403-23-5
Country of Publication:
United States
Language:
English