jspl-introduction of ndt

8/17/2019 Jspl-Introduction of Ndt

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• INTRODUCTION OF NDT


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• NDT METHODS•Penetrant Inspection

•Magnetic Particle Inspection•Eddy Current Inspection

•Ultrasonic Inspection•Radiograpic Inspection

Dye Penetrant Inspection


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Surface breaking defects only detected

Penetrant applied to the component and drawn into the defects by capillary

action

Applicable to all non- porous and non absorbing materials.

Penetrants are available in many different types

Water washable contrast

Solvent removable contrast

Water washable fluorescent

Solvent removable fluorescent

Post-emulsifiable fluorescent



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!e use Non Destructive Testing "NDT# $en $e $is to

assess te integrity o% a structure $itout destroying it

Types o% NDT used are&

Dye penetrant inspection "PT#

Magnetic particle inspection "MT#

Radiograpic inspection "RT#

Ultrasonic inspection "UT#


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Sur%ace 'rea(ing de%ects only detected

Penetrant applied to te co)ponent and dra$n

into te de%ects 'y capillary action

*pplica'le to all non+ porous )aterials,


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First te $or( )ust 'e cleaned torougly- ten a

penetrant is applied %or a speci%ied ti)e

Once te contact ti)e as elapsed- te penetrant isre)o.ed and a de.eloper is ten applied

*ny penetrant tat as 'een dra$n into a crac( 'y capillary

action $ill 'e dra$n out into te de.eloper


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Dye Penetrant nspection

Step 1. Pre-Cleaning

Cleaning preparation is very important on this method.

Usually solvent removal is been used


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Step 2. Apply penetrant

After the application of the penetrant the penetrant is normally

left on the components surface for appro!imately "# minutes

$dwell time%. &he penetrant enters any defects that may be

present by capillary action


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Step 3. Clean off penetrant

After sufficient penetration time $dwell time% has been given'

e!cess removal penetrant stage take place. A damped lint free

tissue with solvent is used to clean the e!cess penetrant.


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Step 3. Apply developer

After the exess penetrant is been removed! a thin layer

of developer is applied.A penetrant dra"n out by reversed

apillary ation.


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Step #. $nspetion % development time

nspection should take place immediately after the developer

has been applied .Any defects present will show as a bleed

out during development time.


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Step &. Post-Cleaning

After the inspection has been performed post cleaning is

re(uired to prevent corrosion.


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Apply Penetrant Clean then apply

Developer

Result



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Colour ontrast Penetrant

'luoresent Penetrant(leed out vie"ed

under a U)-A light

soure

(leed out vie"ed

under "hite light


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Colour ontrast Penetrant

Simple to use

ne!pensive

)uick results*an be used on any non-

porous material

Portability

+ow operator skill re(uired

Surface breaking defect

only

little indication of depths Penetrant may contaminate

component

Surface preparation critical

Post cleaning re(uired

Potentially ha,ardous

chemicals

Advantages Disadvantages


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*ny /uestions*ny /uestions


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• Penetrant dwell times areusually

A.1-5 minutes

B.1-30 minutes

C.5-60 minutes

D.60-100 minutes


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• !en %luorescent penetrant inspection is

per%or)ed- te penetrant 0 )aterials are %or)ulated

to glo$ 'rigtly and to gi.e o%% ligt at a$a.elengt&

*,Close to in%rared ligt

1,Close to te $a.elengt o% 2+raysC,Tat te eye is )ost sensiti.e to under di)

D,ligting conditions In te red spectru)


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• Which type of penetrant is auorescent penetrant?

A.Type IB.Type II

C.Type III

D.Type IV


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• !en re)o.ing $ater $asa'le penetrant te

)a2i)u) $ater pressure 3 sould 'e&

*,45 psi1,67 psi

C,57 psi

D,87 psi


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• De.elopers co)e in a .ariety o% %or)s and can 'e

applied 'y&

• *,Dusting

1,Dipping

C,Spraying

D,*ll o% te a'o.e


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• It is $ell recogni9ed tat )acining- oning-

lapping and and sanding 5 $ill result&

*,In a 'etter penetrant inspection

1,In a longer d$ell ti)e in order to produce ade:uate

penetration o% te penetrantC,;onger d$ell ti)es

D,Metal s)earing


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• !ic de.eloper %or) is used %or nona:ueous Type

I de.eloper<

• For) a

• For) '

• For) c• For) d


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• !ic penetrant )etod is easiest to use in te

%ield<

• *,Fluorescent- post+e)ulsi%ia'le

1,=isi'le dye- $ater $asa'le

C,=isi'le dye- sol.ent re)o.a'le

D,Fluorescent- $ater $asa'le


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Which type of penetrant is mostsensitive?

A.Type IB.Type II

C.Type III

D.Type IV


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Sur%ace and sligt su'+sur%ace detection

Relies on )agneti9ation o% co)ponent 'eing tested

Ferro+)agnetic )aterials only can 'e tested

Metods o% applying a )agnetic %ield- yo(e- per)anent )agnetand prods,

*ny de%ect $ic interrupts te )agnetic %ield- $ill create alea(age %ield- $ic attracts te particles



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Colletion of in*

partiles due to

lea*age field

Prods

+C or AC

,letro-magnet

yo*e +C or AC

Cra* li*e

indiation

Cra* li*e

indiation



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The types of magnetic media used are:

1) Wet in 1) Wet in 4#4# Dry po!derDry po!der 3#3#

"luorescent in "luorescent in

Te $eld lengt )ust 'e crossed at >7? 'y te )agnetic %ield

* )agnetic in( is applied $ic $ill concentrate in areas o%

%lu2 lea(age- as tose caused 'y %la$s

First te $or( )ust 'e cleaned and a $itener applied %or

contrast, * )agnetic %lu2 is ten applied 'y per)anent )agnet-

electro )agnet- or straigt current



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Contrast paint #agnet $ %n Result



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Surface and slight sub-surface detection

elies on magneti,ation of component being tested

/erro-magnetic materials only can be tested

A magnetic field is introduced into a specimen being tested

0ethods of applying a magnetic field' yolk' permanentmagnet' prods and fle!ible cables.

/ine particles of iron powder are applied to the test area

Any defect which interrupts the magnetic field' will create aleakage field' which attracts the particles

Any defect will show up as either a dark indication or in thecase of fluorescent particles under 12-A light a green3yellowindication



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Colletion of in*

partiles due to

lea*age field

Prods

+C or

AC

,letro-

magnet

yol* +C or

AC

Cra*

li*e

indiati

on

Cra*

li*e

indiati

on



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A ra* li*eindiation



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Alternatively to contrast inks' fluorescent inks may be usedfor greater sensitivity. &hese inks re(uire a 12-A light source

and a darkened viewing area to inspect the component



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/ypial se0uene of operations to inspet a

"eld

*lean area to be tested

Apply contrast paint

Apply magnetisism to the component

Apply ferro-magnetic ink to the componentduring magnetising

nterpret the test area

Post clean and de-magnatise if re(uired


M ti P ti l I ti


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Magnetic Particle Inspection

Advantages

Simple to usene!pensive

apid results

+ittle surface

preparation re(uired

0ore sensitive thanvisual inspection

+isadvantagesSurface or slight sub-surface detection only

0agnetic materials

only4o indication of

defects depthsDetection is re(uired

in two directions


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Ultrasonic inspection

"UT#



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Tis detection )etod uses ig %re:uency sound $a.es-

typically a'o.e 4MH9 to pass troug a )aterial

* pro'e is used $ic contains a pie9o electric crystal to

trans)it and recei.e ultrasonic pulses and display te signals on

a catode ray tu'e or digital display

Te actual display relates to te ti)e ta(en %or te ultrasonic

pulses to tra.el te distance to te inter%ace and 'ac(

*n inter%ace could 'e te 'ac( o% a plate )aterial or a de%ect



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*ny i)per%ections $ill re'ound te sound $a.es causing a

signal to occur on te catode ray tu'e

* pro'e is ten applied $it te correct angle %or te $eld

preparation and sound $a.es are trans)itted

First te $or( )ust 'e cleaned torougly- ten a couplant is

applied to increase sound trans)ission



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Apply Couplant &ound !ave

&ignal re'ounded&ignal re'ounded

from (ac of fusionfrom (ac of fusion

CRT display

Result



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defet

1 2 3 # &

defet

eho(a* "all

eho

C/ +isplayCompression Probe

aterial /h*

initial pulse



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• To understand and

appreciate te

capa'ility andli)itation o% UT



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Sub-surface detection

&his detection method uses high fre(uency sound waves'

typically above 506, to pass through a material

A probe is used which contains a pie,o electric crystal totransmit and receive ultrasonic pulses and display the signals

on a cathode ray tube or digital display

&he actual display relates to the time taken for the ultrasonic

pulses to travel the distance to the interface and back

An interface could be the back of a plate material or a defect

/or ultrasound to enter a material a couplant must be

introduced between the probe and specimen



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+aminations detected using compression probes

Pulse echo

signals

A scan Display

1& Set' Digital

*ompression probe &hickness checking the material



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defect

7 "7 57 87 97 #7

defect

echo

*& Display*ompression Probe

0aterial &hk

initial pulse:ack wall

echo



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U/ Set!

+igital

Pulse eho

signals

A san +isplay

Compression probe/hi*ness he*ing the material



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initial pulse

defect echo

defectdefect

defect

7 "7 57 87 97 #7

*& Display

7 "7 57 87 97 #7

initial pulse

defect echo

*& Display

@ S(ip

Full S(ip


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Angle Probe

U/ SetA San

+isplay



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1 2 3 # &

initial pulse defet eho

C/ +isplay

sound path

Angle Probe

defet

Surfae distane



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Advantages

apid results

Sub-surface detection

Safe

*an detect planar defect

*apable of measuring the depth

of defects 0ay be battery powered

Portable

+isadvantages &rained and skilled operator

re(uired e(uires high operator skill ;ood surface finish re(uired Difficulty on detecting

volumetric defect *ouplant may contaminate 4o permanent record



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Radiograpic inspection "RT#


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The principles of radiography

A or Ba))a radiation is i)posed upon a test o'ect

Radiation is trans)itted to .arying degrees dependant

upon te density o% te )aterial troug $ic it is

tra.elling

Tinner areas and )aterials o% a less density so$ as

dar(er areas on te radiograp Tic(er areas and )aterials o% a greater density so$ as

ligter areas on a radiograp

*pplica'le to )etals-non+)etals and co)posites

Radiograpic Testing "RT#


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The types of radiation used in industrial radiography:

1) * rays +from Cathode Ray Tu'e)

) ,amma rays +from a Radioactive %sotope)

*ny i)per%ections in line $it te 'ea) o% radiation $ill 'e

so$n on te %il) a%ter e2posure and de.elop)ent

* %il) is placed inside a cassette 'et$een lead screens,

It is ten placed to te rear o% te o'ect to 'e radiograped

* radiograpic source- is e2posed to te $or( and %il) %or a

pre+calculated ti)e



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Industrial Radiograpy

• A + Rays

Electrically generated

• Ba))a Rays

Benerated 'y te decay

o% unsta'le ato)s



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Industrial Radiograpy

• A + Rays

Electrically generated



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Industrial Radiograpy• Ba))a Rays

Benerated 'y te decay o% unsta'le

ato)s



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Source

adiation beam mage (uality indicator

Radiograpic Inspection

0 7 % e 0 D

&est specimenadiographic film


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Source

adiation beam mage (uality indicator

adiographic film with latent image after e!posure

0 7 % e 0 D

&est specimen

0 7 % e 0 D



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Density - relates to the

degree of darkness

*ontrast - relates to the degree of difference

Definition - relates to the degree of sharpness

Sensitivity - relates to the overall (uality of the

radiograph



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4',12

Step % 5ole type $6$ 7ire type $6$



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7ire /ype $6$

Step%5ole /ype $6$

I)age /uality IndicatorsI)age /uality Indicators



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Radiograpic Tecni:ues• Single !all Single I)age "S!SI#

+ %il) inside- source outside

• Single !all Single I)age "S!SI# panora)ic+ %il) outside- source inside "internal e2posure#

• Dou'le !all Single I)age "D!SI#+ %il) outside- source outside "e2ternal e2posure#

• Dou'le !all Dou'le I)age "D!DI#+ %il) outside- source outside "elliptical e2posure#



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Single $all single i)age S!SI

)s should be placed source side

/ilm

/ilm



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Single $all single i)age S!SI panora)ic

• )s are placed on the film side

• Source inside film outside $single e!posure%

/ilm



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/ilm

Dou'le $all single i)age D!SI

• )s are placed on the film side

• Source outside film outside $multiple e!posure%

• &his techni ue is intended for i e diameters over "77mm



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adiograph

dentification

$+ 11

• 1ni(ue identificationEN !07

• ) placing

A (• Pitch marks

indicating readablefilm length



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adiograph



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/ilm

Dou'le $all dou'le i)age D!DI elliptical e2posure

• )s are placed on the source or film side

• Source outside film outside $multiple e!posure%

• A minimum of two e!posures

• &his techni(ue is intended for pipe diameters less than "77mm



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Dou'le $all dou'le i)age D!DI

Shot A adiograph

dentification

$+ 12

• 1ni(ue identification

EN !07

• ) placing

1 2

• Pitch marksindicating readablefilm length

# 3



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Dou'le $all dou'le i)age D!DI


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AdvantagesPermanent record

+ittle surface preparation

Defect identification

4o material type

limitation

+isadvantages

6armful radiationDetection on defect

depending on orientationSlow resultse(uired license to operate



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jspl-introduction of ndt

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