Visual testing ,Liquid penetrant testing ,Magnetic particle testing,Radiography testing,Ultrasonic testing,non destructive testing. - PowerPoint PPT Presentation

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Visual testing ,Liquid penetrant testing ,Magnetic particle testing,Radiography testing,Ultrasonic testing,non destructive testing.

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Nest Institute of NDT posse’s high quality international standard training for NDT in accordance with quality management system and pursuing placement for candidates to improve their career. To give quality training and education along with placement for the youngsters to enrich their career (or) to make their life delightful.Courses: VISUAL TESTING, LIQUID PENETRANT TESTING, MAGNETIC PARTICLE TESTING, RADIOGRAPHY TESTING, ULTRASONIC TESTING,More Information Visit Our Website nestndt.com – PowerPoint PPT presentation

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Title: Visual testing ,Liquid penetrant testing ,Magnetic particle testing,Radiography testing,Ultrasonic testing,non destructive testing.


1
A PRESENTATION ON NEST NDT
2
  • Nest (National Employment Service and Training)

3
ABOUT US
  • Nest (National Employment Service and
    Training) is a leading training institute for
    ASNT level II. We are the only training centre
    giving 100 placement assistance to the
    candidates till candidates get placed. Our
    trainers are having more than ten years of field
    experience in industries like petroleum
    refineries and power plant (nuclear, thermal).
    The candidates will get both theoretical and
    practical during the training session. We are
    moulding our candidates with advance training
    medium like visual and audio to enrich their
    knowledge. Our candidates will get a globally
    authentication certificates from ASNT America
    Society for Non Destructive Testing level II as
    per SNT-TC-1A standard on successful completion
    of training and practical exams.
  •  
  • Our candidates will get onsite training in the
    particular industries like refineries and power
    plant to get a real time experience. Nest takes
    whole responsibilities of our candidates
    developing in their career. Other than NDT
    training, we are providing Motivation class,
    personality development session to get through in
    their interviews with fear.

4
  • Vision
  •  
  • Nest Institute of NDT posses high quality
    international standard training for NDT in
    accordance with quality management system and
    pursuing placement for candidates to improve
    their career.
  •  
  • Our Mission
  •  
  • To give quality training and education along
    with placement for the youngsters to enrich their
    career (or) to make their life delightful.

5
Visual Testing
  • The earliest and most useful method of NDT is
    visual examination. Important details can be
    collected during VT which would be useful for
    future analysis and also to decide on the types
    of NDT to be used for as further analysis. Also,
    VT should be carried out as a complementary
    method to all other NDT methods. VT should
    proceed and succeed all other examinations.
    Inaccessible areas can be inspected by means of
    boroscope and fiber-optic techniques. Depending
    upon the severity of the surface defect and the
    component in use, decision will be taken for
    salvaging the component or not. If the product is
    found unacceptable during visual examination
    itself, further NDT need not be carried out, thus
    saving time and cost of inspection

6
VT is selected for detecting the following
discontinuities
  • Surface deposits
  • Scaling
  • Corrosion
  • Discoloration
  • Oxidation bulging
  • Missing parts
  • Mechanical damage
  • Dimensional conformance
  • Gross effects visible on the surface
  • Distortion of components during fabrication and
    in services
  • General corrosion on the surface of a component

7
Liquid Penetrant Testing
  • Liquid penetrant testing (LPT) is another
    means of enhancing the capability of visual
    examination. It is suitable for use on smooth
    surfaces of all materials, magnetic as well as
    non-magnetic. It is limited to surface defects.
    Its inability to indicate the depth or breadth of
    flaw should be kept in mind while selecting this
    method for particular application.
  • Use of LPT for porous materials is ruled out
    since the absorption into the pores would mask
    the presence of defects. A clean surface is a
    pre-resist as penetrant cannot enter in to the
    cracks that are filled with dirt, oil, or other
    matter.
  •  
  • Size, shape, weight and number of workpieces to
    be inspected often influence the selection of a
    penetrant system. The desired degree of
    sensitivity and the cost are the most important
    factors in selecting a system.
  •  
  • LPT can also be used for leak testing. In this
    case, the component casting is filled with
    penetrant and developer is applied outside the
    surface.

8
  • LPT is selected for detecting the following types
    of discontinuities on the surface of a component.
  •  
  • Cracks of any orientation
  • Porosity
  • Pin holes
  • Voids
  • Forging laps
  • Forging bursts
  • Lamination in plates
  • Various types of weld defects
  • Corrosion cracks
  • Creep fissures
  • Fatigue cracks

9
Magnetic Particle Testing
  • While LPT is effective only for fine surface
    discontinuities, the need remains to detect
    larger surface flaws or those present just below
    the surface. The need is met by magnetic particle
    testing (MPT). This technique is applicable only
    for ferromagnetic materials. MPT is a considered
    more sensitive than LPT. MPT requires a higher
    degree or operator expertise to ensure that the
    magnetic fields are aligned in the correct
    direction in order to detect the defect. Flaws
    oriented perpendicular to the induced magnetic
    field is only reliably detectable. Hence the
    challenge is to induce magnetic field lines in a
    given work piece so that they are most likely to
    be perpendicular to the flaw orientation.
    Therefore, prior knowledge on flaw orientation
    and or introduction of magnetic fields in several
    directions are is essential.
  •  
  • It is commonly agreed that defects breaking the
    surface are most severe amongst the various
    discontinuities occurring in components. For
    dynamically loaded structures, their removal is
    essential. Their detection in ferrite materials
    is most easily accomplished by MPT. Since the
    depth determination of the surface breaking
    cracks is almost impossible, crack depth
    measurements may be additionally employed to
    asses them. Detection of subsurface defects by
    MPT is impossible if the components are thin, but
    generally it requires ideal testing conditions.

10
  • MPT is used for detecting following
    discontinuities in ferromagnetic materials.
  •  
  • Surface discontinuities
  • Cracks and tears
  • Porosity
  • Shrinking cavities
  • Slag inclusions
  • Voids
  • Forging laps
  • Grinding cracks
  • Corrosion cracks
  • Fatigue cracks
  •  
  • Discontinuities just below the surface (within
    around 6mm depth from the surface sensitivity
    goes down as a defect is deeper)
  •  
  • Larger size cracks in various orientations
  • Pores
  • Slag inclusions
  •  

11
Radiography Testing
  • The other NDT methods are used for detection of
    defects which are open to the surface nearer to
    the surface. To detect more deeply seated
    discontinuities, NDT methods with test medium
    capable of deeper penetration and system that
    senses even minute changes in the
    characteristics, behaviour of the test medium is
    required. Radiographic inspection is one of the
    most widely used methods of NDT as this is
    applied to all metals and alloys, both ferrous
    and nonferrous, for detection of volumetric type
    of defects. The range of capabilities offered by
    the variety of sources and equipments has brought
    radiography to the forefront of NDT techniques.
  •  
  • Testing of multilayer vessels and welds is
    generally a difficult task due to in accessible
    inner layers. RT is the only NDT method to
    evaluate multilayered vessels during
    manufacturing stages and inservice.

12
  • Development of micro focal X-ray units has made
    it possible to extend radiographic practice to
    meet the requirements of more stringent quality
    levels demanded for critical applications,
    besides a host of new applications. It is know
    that the sensitivity in radiography depends to a
    large extend on the focal spot size. In micro
    focal radiography, the focal spot size is less
    than 100microns and typically 15-50 micron as
    compared to a few mm or ½ a mm in conventional
    radiography. Using microfocal RT, intricate
    geometrical components such as tube to tube
    sheet. Welds can be tested with a sensitivity of
    even 1 of wall thickness 0-3mm. microfocal RT
    can be used for detection of micro cracks of
    around 25micron in size. Another application of
    microfocal RT is to check the integrity of
    micro-welds used electronic integrated circuits.
  • One of the advantages of RT is that no prior
    preparation of the surface of the component is
    necessary. The main disadvantage of the RT is the
    possible hazards due to exposure to radiation if
    proper care is not taken.

13
  • RT is selected to detect and size the following
    types of discontinuities
  •  
  • Cracks (parallel to the radiation beam)
  • Volumetric defects such as slag inclusions, voids
    etc
  • Porosity
  • Blockages or deposits inside the pipe lines are
    pressure vessels
  • Material thickness
  • To detect hidden foreign material inside a
    component
  •  

14
Ultrasonic Testing
  • Ultrasonic testing involves use of high
    frequency sound waves coupled to the components
    to be inspected and studying the reflection
    pattern of these waves. UT is finding increased
    applications in various industries. Several wave
    modes such as longitudinal, shear and surface
    waves can be used depending on the orientation
    and location of the discontinuities. Different
    techniques such as pulse-echo, through
    transmission, and pitch-catch or employed. The
    advantages of UT are real time availability of
    results, higher penetrating power of these waves,
    higher sensitivity for planner defects,
    independence sensitivity over depths, low cost
    for inspection, higher portability to the
    equipment and compatibility for automation. But
    the subjectivity of the results on the operators
    training and skill is stumbling block for its
    wider acceptance. With the advent of
    microprocessors and automation, operator
    dependability is being eliminated to a larger
    extent and UT finding increased applications in
    industries such as power, railways, chemical,
    aerospace etc

15
  • UT of cast metals and alloys is renderd
    difficult due to the influence of casting
    intricacy, micro structural variations and
    surface roughness. Defects occurring in the cast
    structure have irregular surfaces which scatter
    the aquostic waves and makes UT more difficult.
    Hence successful use of UT for inspection of
    castings depends greatly upon the skill and
    expertise of the operator.
  •  
  •  
  • UT is the most suitable method of NDT for
    inservice inspection (ISI) of components in power
    plants, chemical process industries, etc. Many
    times, RT cannot be applied for ISI due to the
    requirements of two side accessibility. UT is
    more sensitive flaw growth monitoring has
    compared with RT in view of all these advantages
    the first choice of ISI is UT for volumetric
    defects in components except for heat exchangers
    and condensers where ECT is preferred.

16
  • UT Is Selected To Detect The Size The Following
    Type Of Discontinuities
  •  
  • Surface breaking and hidden cracks in any
    orientation
  • Inter granular cracks
  • Laps
  • Laminations
  • Volumetric defects such slag inclusions, voids,
    ect
  • Porosity
  • Wall thickness measurements
  • Creep
  • Hydrogen encriptment
  • Liquid level measurement
  • To detect blockages, deposits, etc. in the pipe
    lines and pressure vessels
  •  

17
  • THANK YOU
  • FOR MORE INFORMATION
  • Visit
  • nestndt.com
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