APPLICATION

Penetrant testing (PT), is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics). The penetrant may be applied to all non-ferrous materials and ferrous materials, although for ferrous components magnetic-particle inspection is often used instead for its subsurface detection capability. Penetrant test is used to detect casting, forging and welding surface defects such as cracks, laps, seams, cold shuts, delamination, porosity and other types of defects, the penetrant test can be used in visible pénétrant test or flourescent penetrant test, the second is more sensibility than the first.

LIMITATION

• Only surface breaking defects can be detected.
• Only nonporous surface can be inspected.
• Pre-cleaning is critical since contaminants can mask defects.
• Metal smearing from machining, grinding, and grit or vapor blasting must be
• removed.
• The inspector must have direct access to the surface being inspected.
• Surface finish and roughness can affect inspection sensitivity.

APPLICATION

Is a non-destructive testing (NDT) process for detecting surface and shallow subsurface discontinuities in ferromagnetic materials , The presence of a surface or subsurface discontinuity in the material allows the magnetic flux to leak, since air cannot support as much magnetic field per unit volume as metals.To identify a leak, ferrous particles, either dry or in a wet suspension, are applied to a part. These are attracted to an area of flux leakage and form what is known as an indication, which is evaluated to determine its nature, cause, and course of action, the magnetic particle test can be detect defects such as cracks, laps, seams, cold shuts, delamination, porosity and other types of defects

The basic procedure that is followed to perform magnetic particle testingconsist of the following:

• Pre-cleaning of component
• Introduction of Magnetic field
• Application of magnetic media
• Interpretation of magnetic particle indications

BENEFITS

• Large surface areas of complex parts can be inspected rapidly.
• Can detect surface and subsurface flaws.
• Surface preparation is less critical than it is in penetrant inspection.
• >Magnetic particle indications are produced directly on the surface of the part and form an image of the discontinuity.
• Equipment costs are relatively low.

APPLICABILITY OF HT

• • Evaluation of ferrous and no ferrous metals
  • Inspection of weld, weld heat affected zones (HAZ’s), piping, stress relieved material, pressure vessels
  • All boiler and fired heater tubes, furnaces.

BENEFITS OF HT

• The method suiatble for immediate interpretation, rapid testing
• Portability
• Greater accuracy than other nondestructive methods in determining the position of internal flaws, estimating their size, and characterizing their orientation, shape and nature.
• Only one surface needs to be accesible.
• Nonhazardous to operations or to nearby personnel and has no effect on equipment and materials in the vicinity
• Portability

PMI testing is a physical evaluation of a material to confirm that the material which has been placed is consistent with the specified alloy material designated. These tests may provide either qualitative or quantitative information that is sufficient to verify the nominal alloy composition. There are many methods SIS NDT applies Portable X-ray Fluorescence (XRF)

LIMITATIION OF PMI

• It is not possible to detect all elements. XRF may exclude some of the important elements such as C, P, Si and S.
• Surfaces must be prepared by cleaning.
• Pre-cleaning is critical since contaminants can mask defects.

Thermography, also called infrared inspection, is based upon the sensing of heat emitted from the surface of an object in the form of infrared radiation. Test instruments are used to detect and convert the infrared radiation into either a temperature value or a thermal image, which can be used to assess the thermal condition of the object at the time of measurement. An infrared camera is one common type of an infrared thermal imaging device

• Analyze the loading of electronic switching circuits
• Detect faulty conditions during operation
• Determining thermal loss via heaters, boilers or other equipment

LIMITATION OF IRT

• Accurate temperature measurements are hindered by differing emissivities and reflections from other surfaces
• Methods and instruments are limited to directly detecting surface temperatures