![]() Liquid Penetrant Examination Jim Worman Senior Staff Engineer National Board Category: Design/Fabrication Summary: This article was originally published in the Winter 2011 National Board BULLETIN. The part needs to be cleaned to remove all developer after it has been evaluated.Asme Section V Article 6 Pdf 3,8/5 3787 votes Here, the two linear indications are rejectable defects. Length of indication is measured for evaluation, not length of the flaw. Length of an indication can grow over time as penetrant bleeds out, causing an acceptable indication to be a rejectable defect. It is critical to examine the part within the time frame designated in the written procedure. The developer manufacturer’s recommendations and written procedure should be followed closely. The dwell time for developer is typically 10 to 60 minutes. A dwell time needs to be observed to allow time for the dye to exit the flaws and create an indication (flaw) in the developer. Next, cleaner/ remover should be sprayed on another clean, dry, lint-free rag and used to vigorously rub the part again until there is no penetrant visible on the rag.Ī thin, light coating of developer should be sprayed on the part being examined. The part or material should be rubbed vigorously until the penetrant is not visible on the dry rags. The penetrant manufacturer’s recommendations and written procedure should be followed.Īll penetrant should be removed with clean, dry, lint-free rags until thoroughly clean. This is typically 5 to 30 minutes but should never be long enough for the penetrant to dry. A dwell (soak) time needs to be observed to allow for the penetrant to permeate into cracks and voids. This is generally done by spraying penetrant from the aerosol can or applying it with a brush. ![]() ![]() The surface needs to be free of dirt, rust, scale, paint, oil, and grease, and be smooth enough to wipe off the penetrant without leaving residue. This can range from grinding and wire brushing to merely wiping the part with a rag moistened with the cleaner/ remover. ![]()
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