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What is LPI in NDT?
Liquid Penetrant Inspection
What is contact angle in penetrant test?
The contact angle is the angle in which the liquid interface meets the solid surface. The contact angle should be as small as possible to have an effective penetrant material.
What are the chemicals being used in Dye penetrant testing?
FLUROSCENT
What radiation is most penetrating?
The gamma radiation is extremely penetrant.
What are the Types of penetrant inspections?
visible inspection and flourescent insp ection
When conducting a penetrant test what does the spherical indications on the surface of a part mean?
Porosity
Why is the inspection of anodized aluminum impractical with penetrant?
It isn't. The anodize coating providing elctrolytic passivation is considered a dye, not a paint. It is permissable to perform fluorescent penetrant inspection on anodized pieces in the aerospace engine overhaul industry.
What is liquid penetrant test in non destructive testing?
Liquid penetrant inspection is a nondestructive testing method that does not harm the test piece and is commonly used on materials such as metals, glass, plastics and fired ceramics. This nondestructive testing method relies on the liquid penetrant seeping into the flaw, then forming a surface indication that is observed under special lighting after the penetrant is given time to "bleed out" from the flaw. Liquid Penetrant Inspection (LPI or PT) is very effective in detecting flaws that are open to the surface such as fatigue, quench or grinding cracks; forging cracks and bursts; overload and impact fractures; porosity; laps and seams.The ProcessAt Laboratory Testing Inc., the first step in Liquid Penetrant Inspection is to thoroughly clean the surface to be inspected to be sure it is free of oil, grease, water, heat-treat scale, paint, plating and other contaminants that may prevent liquid penetrant from entering flaws. The part may also require etching if mechanical operations such as machining, sanding, or grit blasting have been performed because they can smear metal over the flaw opening and prevent the penetrant from entering.Next, a red visible or fluorescent dye liquid penetrant is applied to the part by spraying, brushing or immersing in a penetrant bath. The liquid penetrant is left on the surface for a sufficient time to allow as much penetrant as possible to seep into a defect. Penetrant dwell time is the total time that the penetrant is in contact with the part's surface.After the dwell time has elapsed, the excess liquid penetrant is removed from the surface. Depending on the penetrant method used, this step may involve cleaning with a solvent (solvent-removable), direct rinsing with water (water-washable), or first treating the part with an emulsifier (post-emulsifiable) before rinsing with water. When using the water-washable or post-emulsifiable methods, the part is placed in a low-temperature oven and allowed time to dry after rinsing.A thin layer of developer is applied to the part to assist in drawing penetrant trapped in flaws back to the surface where it will be visible as indications. Developers may be applied by dusting (dry powder) or spraying (wet developers). These indications are larger than the actual flaw, and therefore, are more visible. When using fluorescent penetrants, indications must be viewed under darkened conditions with a high-intensity UV lamp. The final step in the process is to thoroughly clean the surface to remove any residues.Advantages and LimitationsLiquid Penetrant Inspection offers a fast and relatively inexpensive means of surface inspection since large areas and quantities of parts or materials can be inspected quickly. The process is flexible for inspecting parts of almost any shape and for most materials that are not extremely rough or porous. This process is a nondestructive testing method which does not cause harm to the parts or products being tested. Indications are produced directly on the surface of the part and provide a visual representation of the flaw. Liquid penetrant inspection is highly sensitive to small surface discontinuities.One of the major limitations of a penetrant inspection is that flaws must be open to the surface. Also, surface finish and roughness can affect inspection sensitivity. Pre-cleaning of parts is critical since contaminants can mask defects, and post-cleaning is required to remove residues.
What does the acronym PB stand for?
In the Penetrant PB B'laster, the PB stands for Penetrating B'laster.
How do you remove a 1968 old beetles door hinge from the door?
Impact driver and lots of rust penetrant.
What are the disadvantages of gamma telescopes?
Gamma radiation is very penetrant and is used in medicine, nondestructive testing, etc.
Who can perform Dye penetrant inspection?
Penetrant inspection should be performed by a certified NDT (non-destructive testing) laboratory by a certified (Level II or III) inspector. There are many criteria for succesfully passing Penetrant Inspection. This type of test is usually performed in accordance with some kind of industry standard usually specified on an engineering drawing or blueprint. Just look up NDT or non-destructive testing laboratories in your area and they should be happy to answer more detailed questions.
