Question Paper on Liquid Penetrant Examination

8/13/2019 Question Paper on Liquid Penetrant Examination

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Specific Question Paper on Liquid Penetrant Examination

Time : 1 Hour

Name of the Candidate : Date :

1 If the surface of the part has een machined! sanded or "rit #asted:The part may also require etching

It can be immersed in penetrant for its entire dwell time

It will require a shorter dwell timeIt will need to be heated in order to open any cracks that have been peened over

$ %hich #e&e# of penetrant is the most sensiti&e'Level I

Level II

Level III

Level IV

( )enera##*! there is no harm in usin" a #on"er penetrant d+e## time as #on" as the penetrant:

Is not allowed to dry

Stays viscous

Does not form clumps on the surface of the part

Is mixed with emulsifier

, %hich of the fo##o+in" is an ad&anta"e to LPI'Large areas can be inspected

arts with complex shapes can be inspected

It is portable

!ll of the above is an advantage

5 LPI can e used to test most materia#s pro&ided the surface of the part is: "eated to a temperature above #$$o%

Is not extremely rough or porous

Smooth and uniform

&leaned with number $$' grit

- %hich t*pe of penetrant is a &isi#e penetrant'Type I

Type II

Type III

Type IV

. The pentrants that are used to detect the sma##est defects:Should only be used on aerospace parts

(ill also produce the largest amount of irrelevant indications

&an only be used on small parts less than #$ inches in surface area

Should not be used in the field


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/ The performance of a penetrant:(ill remain consistent as long is it is stored in a temperature range of '$ to #$$o%

(ill only degrade of the temperature exceeds #)$o%

&an be affected by contamination and aging

&an be ad*usted with the dwell time

0 PD stands for:roduct of discontinuities

robability of defectsrobability of detection

ersonnel over distributor

12 The tota# time that the penetrant is in contact +ith the part surface is ca##ed the:Soak time

+aking time

Dwell time

Immersion time

11 De&e#opers are used to:,ake the penetrant fluoresce

-educe the dwell time

ull trapped penetrant material out of the defect

!ll of the above

1$ Surface contaminants can #ead to:! shift in the fluorescent wavelength to a lower angstrom level

The part needing to be redipped in order to produce good results

"igher background fluorescence

!ll of the above

1( %hich t*pe of penetrant is a f#uorescent penetrant'Type I

Type II

Type III

Type IV

1, 3or 45 #i"hts used in LPI! the accepted intensit* is 6666666 micro+atts per square centimet

#$$

'$$

.$$

#$$$

18 %hich of the fo##o+in" +i## produce hi"her sensiti&it* of a penetrant test'Leaving the part immersed in the penetrant for the entire dwell time

Leaving the part immersed in the wet developer for the entire developer time


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/sing a nonaqueous wet developer

!llowing the specimen to drain0dwell during its dwell time

1- Contamination of the penetrant:(ill only take place if the part has not been cleaned

(ill occur because of the crossover between the penetrant and developer

(ill occur if the tank is not covered during the dwell time

(ill change the surface tension and contact angle

1. %hen f#uorescent penetrant inspection is performed! the penetrant materia#s are formu#ateto "#o+ ri"ht#* and to "i&e off #i"ht at a +a&e#en"th:

&lose to infrared light

&lose to the wavelength of x0rays

That the eye is most sensitive to under dim lighting conditions

In the red spectrum

1/ 9inimum penetrant d+e## times are usua##*:#0' minutes

#01$ minutes

'02$ minutes

2$0#$$ minutes

10 De&e#oper is required to:Draw out the penetrant from the discontinuity

rovide contrast between the penetrant and the parts background color

Increase the pentrants fluorescence

+oth ! and +

$2 %hite #i"ht intensit* at the surface of the part +hen usin" a &isi#e d*e penetrant shou#d e

! minimum of '$ foot0candles

! maximum of '$ foot0candles

! maximum of #$$ foot0candles

! minimum of #$$ foot0candles

$1 %et de&e#opers are app#ied:!fter the part has been dryed

Immediately after the excess penetrant has been removed from the parts surface

!fter the emulsifer dwell time

!fter the part has been dipped in cleaner3remover

$$ %hich of the fo##o+in" shou#d e remo&ed in order to otain a "ood penetrant test'Varnish

4xides

lating

!ll of the above


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$( %hite #i"ht intensit* at the surface of the part +hen usin" f#uorescent penetrant shou#d e:

! minimum of #$$ foot0candles

! maximum of #$$ foot0candles

! minimum of '$ foot0candles

! maximum of ) foot0candles

$, "ood c#eanin" procedure +i##:-emove all contamination from the part and not leave any reside that may interfere with the

inspection process

-emove a small amount of metal from the surface of the part

Should leave the part slightly flourescent in order to identify any discontinuities

Should etch the part slightly only if it is made from 5$5# aluminum

$8 %hich penetrant method is easiest to use in the fie#d'%luorescent6 post0emulsifiable

Visible dye6 water washable

Visible dye6 solvent removable%luorescent6 water washable

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Question Paper on Liquid Penetrant Examination