ASR Ndt_fundamentals Rev-03

8/6/2019 ASR Ndt_fundamentals Rev-03

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1. Introduction2. Scope

3. Objectives

4. Brief description of NDT

5. Application of NDT methods6. Selection of NDT methods

7. Visual testing

8. Magnetic particle testing.

9. Liquid penetrant testing 10. Ultrasonic testing.

11. Radiography testing

12. Leak testing

13. Eddy current testing. 2Cont,d



W elcome to the session of nondestructive testing .

NDT methods are used to examine the materials or components withoutdestroying it, This has played a very important role in the industry.

Nowadays almost all industries are using various NDT methods to controlthe quality of their products.

In RIL we are using various NDT methods to control the quality of ourproject components like- pressure vessel, piping, welding, casting etc .

Most common methods used are RT,MT,UT,PT and VT.

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NDT methods are used to detect surface ,subsurface and

internal discontinuities in the materials and give qualitycontrol checks in the various stages of manufacturing .

ASME sec ²V is the relevant code for the various NDT

methods used in the industries.

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RELIANCE ENGINEERING ASSOCIATES (P) LIMITED 5

3.1. To bring awareness of various NDT methods, their applications,advantages and limitations.

3.2. To share our field experience and discuss case studies to high light

the importance of NDT.



Various NDT methods are used in the industries for thevarious purpose at different stages.The mechanism of each method varies and is based on thescientific principles. They are based on the application ofsound energy , electrical energy, mechanical energy ,magnetic energy, etc. Photo graphic principle of light energyalso used.Each method has its own advantage and limitations .They are used in various fields like medical field ,Engg.industries and also in day to day life.

Sonography is used to check the sex of unborn child .X-ray are used in the air port to check the luggage of thepassengers.MT ,UT and PT are used in the industries.

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NDT methods are used for different applications. Some of themare listed below:

5.1. Defect detection- type, size & location of defects.

5.2. Checking of various properties ² Density , chemicalcomposition , electrical and thermal conductivity.

5.3. Sorting out mix up of material ²composition , grain size,chemical composition & heat treatment conditions.

5.4. Dimensional gauging ²material thickness & coating

/plating thickness check .

In RIL W e are using NDT methods mostly for defect detectionand thickness checking of the pipes, plates,forgingscastings and welding.

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Selection of NDT method to check the quality of product

is based on the following information.

6.1. Type & location of the defect.

6.2. Nature of the defect.

6.3. Expected orientation of the defect.

6.4. Surface condition.

6.5. Applicable code & standards, (ASME,BS,IS,DIN etc,).

6.6. Quantity of material and facilities of NDT method .

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6.7. Inspection at site or at workshop.

6.8. Accessibility for the site inspections.

6.9. Environmental condition (temperature, wind, height, radiation

hazard).6.10. NDT instrument availability.

6.11. Cost &Time required

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� Visual testing is the oldest and simple NDT method and mostcommonly used everywhere. It is used to detect surface defects likeslaps, cracks, blow holes and many other defects which are visible to

naked eyes. Nowadays sophisticated instruments like boroscope,fibroscope, magnifying lenses etc, are also used.

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� The magnetism is induced in the part by electricity or by using permanent magnet resulting the flow of lines of magnetic flux in thepart.

The magnetic lines of force which pass through the component arebreaking due to discontinuity in the material .

This broken lines are checked by using iron powder forming thedefect indications on the surface at the area where discontinuities arepresent .

� MT is applicable to ferromagnetic material only .

� It is applicable for the detection of surface and sub surfacediscontinuities only .

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Magnetic field

indicator

Magnetic gauss

meter

MPT kits

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Cont,d

Magnetic particle testing



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Lifting Power of Yoke



This testing is applicable for detecting defects open tosurface.

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20 micron nickel chromium test

plate



Procedure�Clean the surface area tobe tested�Apply penetrant bybrushing or spraying, waitfor 7 to 15 min, (dwelltime).�Remove excess penetrantby wiping with lint freecloth.�Apply developer and waitfor 15 minute.�Inspection and evaluationof the defects .� Cleaning to be done withlint free cloth only.

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Limitation for testing

�Surf ace temperature with in 10

to 52 c.

�Smooth surf ace is required .�Porousmaterial can not be

tested.



Penetrant

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DeveloperCleaner



Ultrasonic sound waves are generated by using electricaltransducer . These waves are transmitted in the material byusing couplant. The sound waves are flowing inside the

material and are disturbed by the presence of discontinuitiesin the material. The path of sound wave and its disturbance ismonitored on the CRT screen.

The loss of sound energy ( amount & location ) is indicated onthe screen. which gives the idea about the defects , its size &

location.

(cont,d)

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(cont,d)

Ultrasonic testing.



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(cont,d)

Probe

Test jobFlaw

Indication

ltrasonic Flaw Detector



Ultrasonic testing transducer

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Inspection



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Phase array ltrasonic testing



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Ultrasonic thickness testing

Thickness reading



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Transmitter Receiver

Sound

beam

LATER ALWAVE



Radiography testing depends upon the ability of x-rays or gammarays to penetrate the test material .During penetration the rays arepartially absorbed by the material . The amount of absorptiondepends upon the density and the thickness of material. Defectiveareas do not absorbs the radiation energy. Difference in radiationenergy due to presence of discontinuity is recorded on aphotographic film.

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Information required for

testing

�Thickness and diameter

�Material

Limitation for testing

� R adiation hazard

� Surf ace temperature with in 0 to

45 c for contact technique .

� Surf ace roughness



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11. R adiography testing

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The ability to find out the leakages using air / gas

medium at pressure or at vacuum.

The air or gas is filled in the vessel/ tank at therequired pressure and temperature. The leakage is

detected by the loss of pressure checked bypressure gauge.Some times soaps solution is also used which formsair bubbles at the area of leakage.

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�This method is used for various applications such as mixmetal sorting , dimension gauging, detection of defect

,measuring electrical conductivity etc.

�Principle of eddy current is based on the generation ofinduced current in the material and monitoring on thescreen.

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Multielement probe Magnetic saturation head

Lift-off

adjustment

Non-contact probe 1.5 mm

Magnetic

saturation

coil

ASR Ndt_fundamentals Rev-03

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