DEPARTMENT OF MECHANICAL ENGINEERING
3RD SEMESTER MECHANICAL
MATERIA SCIENCE AND METALLURGY (2131904)
YEAR-2014
“DYE PENETRATE INSPECTION”
PREPARED BY
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130600119011
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BARIA JAYDEEP
DARJI MAHESHKUMAR V.
DHALIWAL HARPRETSINGH H.
GOLWELKAR ANMOL D.
GUIDED BY:
PROF.DHAVAL K PATEL
INTRODUCTION
 This module is intended to provide an introduction to the NDT method
of penetrant testing.
 Penetrant Testing, or PT, is a nondestructive
testing method that builds on the principle
of Visual Inspection.
 PT increases the “seeability” of small
discontinuities that the human eye might
not be able to detect alone.
MATERIALS
Penetrants are classified into sensitivity levels. Visible penetrants are
typically red in colour , and represent the lowest sensitivity.
Fluorescent penetrants contain two or more dyes fluorescent when
excited ultraviolet radiation (also known as black light).
since fluorescent penetrate inspection is performed darkened
environment ,and the excited dyes emit brilliant yellow gring light that
contrasts strongly again the dark background , this material is more
sensitive to small defects.
6 Steps in Penetrant flaw detection
Surface preparation
Penetrant application
Removal of excess penetrant
Application of developer
Inspection
Post cleaning and protection
1) Clean & Dry Component
2) Apply Penetrant
3) Remove Excess
6) Post Clean Component
5) Visual Inspection
4) Apply Developer
What Can Be Inspected Via PT?
Almost any material that
has a relatively smooth,
non-porous surface on
which discontinuities or
defects are suspected.
What Can NOT be Inspected Via PT?
Components with rough surfaces,
such as sand castings, that trap and
hold penetrant.
Porous ceramics
Wood and other fibrous materials.
Plastic parts that absorb or react with
the penetrant materials.
Components with coatings that
prevent penetrants from entering
defects.
Defect indications become
less distinguishable as the
background “noise” level
increases.
Advantages of Penetrant Testing
 Relative ease of use.
 Can be used on a wide range of material types.
 Large areas or large volumes of parts/materials can be inspected
rapidly and at low cost.
 Parts with complex geometries are routinely inspected.
 Indications are produced directly on surface of the part providing a
visual image of the discontinuity.
 Initial equipment investment is low.
 Aerosol spray cans can make equipment very portable.
Limitations of Penetrant Testing
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Only detects surface breaking defects.
Requires relatively smooth nonporous material.
Precleaning is critical. Contaminants can mask defects.
Requires multiple operations under controlled conditions.
Chemical handling precautions necessary (toxicity, fire, waste).
Metal smearing from machining, grinding and other operations inhibits
detection. Materials may need to be etched prior to inspection.
 Post cleaning is necessary to remove chemicals.
THANK YOU