Interview 1.doc

8/12/2019 Interview 1.doc

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1. What is the importance of the Thermodynamics in the field of Mechanical

Engineering?

All the mechanical engineering systems are studied with the help of thermodynamics.Hence it is very important for the mechanical engineers.

2. How many Laws of Thermodynamics are there?

There are three laws of the thermodynamics.First Law:Energy can be neither created nor destroyed. It can only change forms.In any

process in an isolated system, the total energy remains the same.

econd Law:When two isolated systems in separate but nearby regions of space, each inthermodynamic equilibrium in itself, but not in equilibrium with each other at first, are at

some time allowed to interact, breaing the isolation that separates the two systems, and

they e!change matter or energy, they will eventually reach a mutual thermodynamic

equilibrium. The sum of the entropies of the initial, isolated systems is less than or equalto the entropy of the final e!changing systems. In the process of reaching a new

thermodynamic equilibrium, entropy has increased, or at least has not decreased.

Third Law:As temperature approaches absolute "ero, the entropy of a system

approaches a minimum.!. "s the #oiler a closed system?

#es definitely the boiler is a closed system.

$. What is %arnot engine?

It was being designed by $arnot and let me tell you that $arnot engine is an imaginary

engine which follows the $arnot cycle and provides %&&' efficiency.

&. Which form'la forms a lin( #etween the Thermodynamics and Electro

chemistry?

(ibbs Helmholt" formula

). Which is the hardest compo'nd (nown?

)iamond.*. What is Hess Law?energy transfer is simply independent of the path being followed.

+. Which has more efficiency: ,iesel engine or -etrol engines?

*ff course )iesel engine has the better efficiency out of two.

1. What is the difference #etween %ritical peed and Whirling peed?

ns. In +olid mechanics, in the field of rotor dynamics, the critical speed is the

theoretical angular velocity which e!cites the natural frequency of a rotating obect, suchas a shaft, propeller or gear. As the speed of rotation approaches the obects natural

frequency, the obect begins to resonate which dramatically increases system vibration.

The resulting resonance occurs regardless of orientation. Whirling +peed is due to theunbalanced forces acting on a rotating shaft.

2. How a ,iesel Engine Wor(s as /enerator?

ns. )iesel engine is a prime mover, for a generator, pump,and for vehicles etc.

generator is connected to engine by shaft. mostly in thermal power plat ,there is an engine

is used to drive generator to generate power.


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). How to Find0 ,'ctilerittle Transition Temperat're in Metals?

ns. The point at which the fracture energy passes below a pre-determined point for a

standard Impact tests. )TT is important since, once a material is cooled below the)TT, it has a much greater tendency to shatter on impact instead of bending or

deforming.

+. What is the difference #etween -11 and -12 -ipes?

ns. /%% the chromium molybdenum composition that is %' ofchromium and %01' of

molybdenum/%2 the chromium molybdenum composition that is %' ofchromium and 2' of

molybdenum

1. What is the difference #etween Technology and Engineering?

ns. Engineering is application of science. Technology shows various methods of

Engineering. A bridge can be made by using beams to bear the load,by an arc or by

hanging in a cable3 all shows different technology but comes under civil engineering and

science applied is laws of force0load distribution.

2. How to Meas're Temperat're in Wet 'l# Thermometer?

ns. Wet bulb temperature is measured in a wet bulb thermometer by covering the

bulb with a wic and wetting it with water. It corresponds to the dew point temperature

and relative humidity.

$. What is -owder Technology?

ns. /owder technology is one of the ways of maing bearing material. In this method

metals lie bron"e, Al, 4e are mi!ed and compressed to mae an alloy.

). tate the difference #etween 3nilateral and ilateral Tolerance?

ns. A unilateral tolerance is tolerance in which variation is permitted only in onedirection from the specified direction.e.g. %5&& 6&.&&&0-&.&7&

ilateral tolerance is tolerance in which variation is permitted in both direction from the

specified direction.e.g. %5&& 6&.&7&0-&.&7&

*. What is the a##re4iation of welding rod )51*?

ns. 8&%5 9

8&9tensile strength 8&&&&psi%9 welding position

59current flu!

+. What is difference #etween Welding and ra6ing?

ns. In Welding concentrated heat :high temperature; is applied at the oint of metal

and fuse together.In ra"inginvolves significantly lower temperatures and does not entail the melting of

base metals. Instead, a filler metal is melted and forced to flow into the oint through

capillary action.


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1. What is ,ifference #etween stamina and strength?

ns. +trength is capability over a short length of time and +tamina is the ability to eep

going continuously.

2. What is Hydrostatic ystem?

ns. Hydrostatics is the study of s a closed loop hydraulic systems. It comprises of motor and pump. Here pump

supplies energy to motor and motor gives return energy to pump supply.

!. How is the e7cess discharge press're pre4ented?

ns. )ischarge pressure prevented by a pressuri"ed spie cushion. Here the systememploys a pressuri"ed cushion of air and a two o-ring piston, which permanently

separates this air cushion from the water system. When the valve closes and the water

flow is suddenly stopped, the pressure spie pushes the piston up the arrester chamberagainst the pressuri"ed cushion of air. The air cushion in the arrester reacts instantly,

absorbing the pressure spie that causes water hammer.

$. What is the difference #etween trainer and Fitler?

ns. +trainer for coarse si"e, 4ilter is more accurate than +trainer.

*. What is meanst #y 8ne Tonn ir%onditioner?

ns. % ton refrigeration means 2%& ?0min e!tracts heat from thesystem.

15. "f yo' heat a steel pipe with the hole at center0 does heat affects the hole

diameter?

ns. It gets bigger.

1. Why the %entrif'gal -'mp is called High ,ischarge p'mp?

ns. $entrifugal pump is a inetic device. The centrifugal pump uses the centrifugal

force to push out the fluid. +o the liquid entering the pump receives inetic energy fromthe rotating impeller. The centrifugal action of the impeller accelerates the liquid to a

high velocity, transferring mechanical :rotational; energy to the liquid. +o it dischargesthe liquid in high rate. It is given in the following formulae@$entrifugal force F9 M;.

Where,

=-=ass-elocity

B-Badius


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2. How %a4itation can #e eliminated #y -'mp?

ns. $avitation means bubbles are forming in the liquid.

C To avoid $avitation, we have to increase the /ump si"e to *ne or Two Inch3To increase the pressure of the +uction Head, or

C )ecrease the /ump +peed.

@. Why %a4itation will occ'r in %entrif'gal -'mp and not in ,isplacement

-'mp?

ns. The formation of cavities :or bubbles; is induced by flow separation, or non-uniform flow velocities, inside a pump casing. In centrifugal pumps the eye of the pump

impeller is smaller than the flow area of pipe. This decrease in flow area of pump results

in increase in flow rate. +o pressure drop happened between pump suction and the vanes

of the impeller. Here air bubbles or cavities are formed because of liquid vapour due toincrease in temperature in impeller. This air bubbles are transmitted to pump which forms

cavitation.

!. Which -'mp is more Efficient %entrif'gal -'mp or eciprocating -'mp?ns. $entrifugal pump. ecause flow rate is higher compared to reciprocating pump.

4low is smooth and it requires less space to install. Dower initial cost and lowermaintenance cost.

$. Why %entrif'gal -'mp is not called as a -ositi4e ,isplacement Type of

-'mp?

ns. The centrifugal has varying flow depending on pressure or head, whereas the

/ositive )isplacement pump has more or less constant flow regardless of pressure.

Diewise viscosity is constant for positive displacement pump where centrifugal pump

have up and down value because the higher viscosity liquids fill the clearances of thepump causing a higher volumetric efficiency. When there is a viscosity change in supply

there is also greater loss in the system. This means change in pump flow affected by the

pressure change.*ne more e!ample is, positive displacement pump has more or less constant efficiency,

where centrifugal pump has varying efficiency rate.

1. Why Entropy decreases with increase in temperat're?

ns. ds9dA>T Entropy is inversely proportional to the temperature so, as temp.

Increases, entropy decreases.

@. How m'ch Watt means 1Hp?

Ans. 817.2 Watt

). When %r'de 8il is Heated0 Which Hydro %ar#on comes first?

ns. atural gas :(asoline;F at 2& $elsius

+. The Fatig'e life of a part can #e impro4ed #y?


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ns. Improving the surface finish by /olishing G providing residual stress by +hot

peening.

What is heat treatment and why is it done?

Heat treatment can #e defined as a com#ination of processes or operations in which

the heating and cooling of a metal or alloy is done in order to o#tain desira#lecharacteristics witho't changing the compositions. ome of the moti4es or p'rpose

of heat treatment are as follows:

B "n order to impro4e the hardness of metals.

B For the softening of the metal.

B "n order to impro4e the machina#ility of the metal.

B To change the grain si6e.

B To pro4ide #etter resistance to heat0 corrosion0 wear etc.

Heat treatment is generally performed in the following ways:

B Cormali6ing

B nnealing

B pheroidisingB Hardening

B Tempering

B 'rface or case hardening

What are the r'les that m'st #e (ept in mind while designing castings?

ome of the points that m'st #e (ept in mind d'ring the process of cast designing

are as follows:

B To a4oid the concentration of stresses sharp corners and freD'ent 'se of fillets

sho'ld #e a4oided.

B ection thic(nesses sho'ld #e 'niform as m'ch as possi#le. For 4ariations it m'st

#e done grad'ally.

B #r'pt changes in the thic(ness sho'ld #e a4oided at all costs.

B implicity is the (ey0 the casting sho'ld #e designed as simple as possi#le.

B "t is diffic'lt to create tr'e large spaces and henceforth large flat s'rfaces m'st #e

a4oided.

B We#s and ri#s 'sed for stiffening in castings sho'ld as minimal as possi#le.

B %'r4ed shapes can #e 'sed in order to impro4e the stress handling of the cast.

What are the points that sho'ld #e (ept in mind d'ring forging design?

ome of the points that sho'ld #e followed while forging design are:

B radial flow of grains or fi#ers m'st #e achie4ed in the forged components.

B The forged items s'ch as drop and press forgings sho'ld ha4e a parting line that

sho'ld di4ide the forging into two eD'al hal4es.

B The ri#s in a forging sho'ld not #e high or thin.

B "n order to a4oid increased die wear the poc(ets and recesses in forgings sho'ld #e

minim'm.

B "n forgings the parting line of it sho'ld lie as far as possi#le in a single plane.

B For ease of forging and easy remo4al of forgings the s'rfaces of the metal sho'ld

contain s'fficient drafts.


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Do you stop cooling-water flow through a steam condenser as soon as the turbine

is slopped?

#ou should eep the cooling water circulating for about % mill or more so that thecondenser has a chance to cool down gradually and evenly. e sure to have cooling water

flowing through the condenser before starting up in order to prevent live steam from

entering the condenser unless it is cooled. *verheating can cause severe leas and otherheadaches.

How can the deposits be removed?

o Water soluble deposits may be washed off with condensate or wet steam.

o Water insoluble deposits are removed mechanically after dismantling the

turbine.o E!perience shows that water soluble deposits are embedded in layers of

water-insoluble deposits. And when the washing process is carried out,water soluble parts of the deposit dissolve away leaving a loose, friable

seleton of water-insoluble deposits which then brea loose and wash

away.

How can the fatigue damage on high-pressure blades be corrected?4atigue-damage on high-pressure blades arises due to vibration induced by partial-arc

admission. This can be corrected by switching over to full arc admission technique.

+imple%. What is the A+=E code followed for design of piping systems in /rocess pipings

:Befineries G $hemical Industries;

:i; J%.% :ii; J%.J :iii; J%. :iv; J%.K Answer :III;

2. What do you mean by following items

i.;I+D-1&& ii; I+=-7&& iii; I+H-J& iv; I+=$-J&& v; I+?-%& vi; I+D-2&&vii;I+=-1& viii;I+W-1&& i!; I+?$-2&& !; I+D$-J& !ii; I+=$-2&Answer@ i.Indian +T) light weight beam, Web si"e L 1&& ii.Indian +T) medium weight

beam, Web si"e L 7&& iii.Indian +T) MH> beam, Web si"e L J& iv.Indian +T) medium

weight channel, Web si"e LJ&& v.Indian +T) unior beam, Web si"e L %& vi.Indian +T)light weight beam, Web si"e L 2&& vii.Indian +T) medium weight beam, Web si"e L 1&

viii.Indian +T) wide flange beam, Web si"e L 1&& i!.Indian +T) unior channel, Web

si"e L 2&& !.Indian +T) light weight channel, Web si"e L J& !i.Indian +T) mediumweight channel, Web si"e L 2&

J. What is this item

i.I+A-%&&N%&&N%2 ii; I+A-5&N&N%& iii;I+DT-%&&N%&& Answer@ i.Equal angle si"e%&&!%2 THO ii.Pnequal angle si"e 5&!&!%& THO iii.Indian +T) light weight tee bar

si"e %&&!%&&

Which one is preferred

4or branching of one si"e lesser of run pipe, +tub *n is preferred. 4or other branching less than one

si"e of run pipe stub in is preferred. The )esign is based on A+I J%.J .


7/23


8/23

%K. What is the thumb rule to calculate spanner si"e for given bolt Answer@ %. ! diameter of olt

2&. What is the thumb rule to calculate $urrent required for Welding Answer@ $urrent :Amp; 9

S )iameter of Electrode :mm; N 1& 6 2&

22. Which piping items will you drop down before conducting 4lushing and Hydrotest Ans@ Itemslie $ontrol alve, *rifice plates, Botameters, safety valves , Thermowells are dropped or replaced

with temporary spools before hydro test.

2. Which parameters will u chec during checing /iping Isometrics

Ans@ ill of =aterial, /ipe Bouting wrt (A), +upporting arrangement , details of insulation,

hydrotest pressure, painting specs and provision of ent and )rains at appropriate locations.

27. What is the A+I0A+=E dimensional standard for steel flanges G fittings :i; %7.J :ii; %7.

:iii; %7.K :iv; %7.%& Answer :II;

28. How can flanges be classified based on facing a. 4lat 4ace b. Baised 4ace c. Tongue and groove

d. Bing type oint

25. What do you mean by AABH :4lange 4inish; Ans@ Arithmetic Average Boughness Height.

2K. Which are the different types of (asets Ans@ 4ull 4ace, +piral Wound, *ctagonal Bing Type,

=etal ?aceted and Inside olt $ircle.

J&. What should be the relative hardness between the BT? gaset and flange groove

Ans@ 4or a BT? flange , the oint ring should have a J&-1& icers hardness less than that of the

mating face of flange.: rinnel hardness for BT? groove shall be 2&-& H more than the

corresponding gaset hardness;

J%. 4rom which side of pipe will you tae a branch connection

Ans@ When 4luid is (as, Air or +team and $ryogenic +ervice L Topside. When 4luid is Diquid L

ottom +ide. J2. Why don>t we tae a branch for $ryogenic +ervice from bottom side though the

fluid is in liquid state Ans@ There is the chance of Ice formation during normal operation and since

ice flows from the bottom of the pipe it will bloc the branch pipe connection.

J1. How do you support any small si"e H)/E0/$ :/lastic; pipe Ans@ It should be supported

continuously by using channel or Angle so that line should not +ag or fall from the sleeper0rac due to

uneven e!pansion because of Hot Temp.

J. Why do we provide High /oint ent :H/; and Dow /oint )rain :D/); in piping Ans@ H/ L

for removing Air during Hydro-test.D/) L for draining water after conducting Hydro-test.

J8. What do you mean by IB and Which lines comes under IB purview Ans@ IB@ Indian oiler

Begulation Act. +team lines with conditions listed bellow comes under IB purview L U Dines for

which design pressure is J. g0sq cm and above. U Dine si"e above %&Q having design pressure %.&

g0sq cm and above. U oiler feed water lines to steam generator, condensate lines to steam generator

and flash drum.

J5. What are Weldolet and +ocolet And where they are used


9/23

Ans@ Weldolet and +ocolet are basically self reinforced fittings. Weldolet is used for utt weld

branch connection where standard tee is not available due to si"e restrictions and the piping is of

critical 0 high pressure service. +ocolet is used for socet welding branch connection, which require

reinforcing pad.

JK. What is the =*$ for +uperheated high pressure +team Dines

Ans@ A JJ (r / I 0 / II $omposition @ &. =o:/%; 0%.2 ' $r-. =o:/%%;

1&. What is the normal upstream and downstream straight length of orifice flow meter

Answer @ Ppstream %) )ownstream - )

1J. What do you mean by $omposite 4lange The flange that is made up of more than one =*$ is

called a $omposite flange. a. Dap ?oint 4langes Insert 4langes are a specialty in the arena of pipe si"e

flanges and consist of two parts - the insert and the flange ring. The flange ring is the outer part of the

insert flange assembly, containing the bolt holes. The two piece construction of the insert flange also

offers the economy of matching the insert material to the process pipe :usually some corrosion

resistant alloy; while the outer flange ring may be manufactured from steel. When the environment

req uires the flange ring to be made of some alloy the rotating feature is still maintained. b. B4 flanges

with Baised of one =*$ and rest of the flange with different =*$ c. B4 blind flange with an overlay

of K&0%& $uni for +ea water service.

18. What is the min. distance to be maintained between two welds in a pipe The rule of thumb is that

the minimum distance between adacent butt welds is %). If not, it is never closer than %-%02V. This is

supposedly to prevent the overlap of HA s. =inimum spacing of circumferential welds between

centrelines shall not be less than 1 times the pipe wall thicness or 2 mm whichever is greater.

15. What are the different hardness tests carried out Ans@ rinell Hardness Test Bocwell Hardness

test icer Hardness Test

1K. What is the relation between rinell Hardness o and Bocwell Hardness o Ans@ 22 HB$

:Bocwell Hardness; 9 2J5 H :rinell Hardness o; Harder

%.)uring fabrication you observed that one small crac has appeared on a fresh plate, what type of

measure you will tae to obtain desired quality with minimum wastage

Answer@ 4irst identify the e!act length of crac by )/ test. )rill on the end point to resist further

crac. Bemove the crac portion by cutting the strip.

$rac

)rilling /oint

J. )escribe different types of destructive and non-destructive tests Answer@ )E+TBP$TIE TE+T@

end test, Tensile test, Impact test, and Hardness test. *-)E+TBP$TIE TE+T@ )/T, =/T,

Badiography and ultrasonic test

1. What is mean by M/WHT> Why it is required Answer@ R/*+T WED) HEAT TBEAT=ETQ

This is done to remove residual stress left in the oint which may cause brittle fracture.

. What is the minimum thicness of pipe that requires stress relieving to be done as per J%.J Ans@

%K mm th.

8. What is the $ode for +our +ervice

Ans@ $ode for +our +ervice is A$E :A$E =B L &%8; A$E@ ational Association of $orrosion

Engineers.

5. How much should be the pressure for Hydro-Test


10/23

Ans@ Hydrotest pressure should be calculated as follow e!cecpt as provided against point no-1. %. %.

Times of )esign /ressure.

Which fluid is used in Heat E!changer in shell side and tube side

Ans@ (enerally corrosive fluid is used from the tube side :as tube can be easily replaced; and cleaner

fluid is used from shell side. +ometimes Hot fluid is also used from the shell side.

%2. What is Beynold>s number and what is the value of Beynold>s number upto which the flow is

laminar Ans@ It>s a dimensionless number to classify the nature of flow. Be9 vd0 Where@ Be @

Baynold>s no. ass )ensity of fluid. d @ diameter of /ipe. @ average velocity of fluid.

iscocity of fluid. 4low is laminar upto Be92%&&

25. What is the mill tolerence to be considered for the thicness of pipe during stress analysis as per

A+=E J% :i; :ii; :iii; :iv; %' 2.' 8.' %2.'

45. What should be the material of shoes for supporting AS pipes &

why? Ans: If S shoes are used !ad in "onta"t with the pipe to be of

Alloy steel to a#oid dissimilar welding at pipe. $o a#oid alloy

steel welding and dissimilar welding fabri"ated "lamps either of S

or SS "an be used.

4%. What is the allowable stress range for S pipes.

Ans: '(' )g*"m

1. Describe the difference between QA & QC?

Answer: Quality Control is the operational techniques (Inspection, !a"ination & #estin$% that areused to fulfill require"ents for quality. Quality Assurance is the syste" of action and plannin$needed to proide confidence that a 'roduct or erice will satisfy quality require"ents

). *hat do quality syste" audits ealuate?

Answer: #he de$ree of quality syste" confor"ance to established require"ents.

Mechanical/Welding+. *hat is an essential ariable as related to a *eld 'rocedure pecification (*'%?

Answer: A chan$e in a weldin$ condition that will affect the welds "echanical properties.

-. *hat is the relationship between a 'rocedure Qualification ecord ('Q% and a *'?

Answer: #he 'Q docu"ents what occurred durin$ the weldin$ and testin$ of the test coupon.

/. 0eat input (A* per A I2% is a co"bination of what two electrical characteristics & trael speed?

Answer: 3olta$e and A"pera$e

4. !cessie heat input is "ainly attributed to what poor weldin$ techniques durin$ A* process?

Answer: !cessiely wide weain$ and slow trael speed.

5. *hat are 6 potential sources of 0ydro$en encountered durin$ A* process?

Answer: oisture in the "etal and electrode coatin$, oil, ele"ental 0ydro$en in the base "etal

7. *hat are seeral li8ely causes of porosity in carbon steel welds usin$ the A* process?

Answer: 'oor weldin$ technique and equip"ent, e!cessie wind, "oisture & weld conta"inants.

19. *hat di"ension is "easured to deter"ine the si:e of a concae fillet weld?

Answer: #hroat

1). *hat di"ension is "easured to deter"ine the si:e of a cone! fillet weld?

Answer: ;e$

16. *here would crac8in$ "ost li8ely occur fro" e!cessie current input in a sin$le pass weld?


11/23

Answer: Centerline of the weld

1+. bac8 $assin$ on "aterial?

Answer: !idation at the ID (u$arin$%

1-. @a"e 6 of the - "echanical tests in A I2 e"ployed for procedure & perfor"ance qualifications?

Answer: #ension, =uided end, Billetweld, @otchtou$hness & tudweld tests

Mechanical/NDT (assume SMAW process used for allquestions)

1/. 0ow is a$netic 'article inspection of a weld usin$ the wet continuous test "ethod perfor"ed?

Answer: #he particles (usually fluorescent% are sprayed, poured on or applied by i""ersion andthe "a$neti:in$ current is applied while the particles are still flowin$.

14. Indications with ;iquid 'enetrant #estin$ are easily seen if the surface has been prepared by $rindin$prior to testin$? #rue>false? *hy?

Answer: Balse, because $rindin$ can s"ear "etal and "as8>coer discontinuities.

15. @a"e an @D# "ethod and technique that e"ploys a reflected sound bea" that can be used for theolu"etric e!a"ination of welds?

Answer:


12/23

Answer: #he wner

)5. 'er A 61.6 (assu"e latest edition%, what are the # require"ents for oc8et welds in seere cycleserice?

Answer: @one

)7. elatin$ to the aboe question, =ie $ood reasons why rando" # of soc8et welds is reco""ended?

Answer: oth $ross weldin$ defects & poor quality welders can be identified, with repairs and

correctie action ta8en, & =ap can be erified.

69. riefly describe $ood QC practice relatin$ to the installation & boltin$ of flan$es?

Answer: 3erify aterials (type, si:e and ratin$% are acceptable, $as8et erification & $ood boltin$practices (torque alue require"ents "et% in accordance with approed procedures.

61. *hat is an oftenoerloo8ed Inspection>@D# require"ent on the installation of an orifice flan$e?

Answer: 3isual weld inspection of the seal weld & @D# has been "issed prior to boltin$ of flan$es

6). 'er A ection 3III, Di. 1, can a no::le to be attached to the e!terior surface of a pressure esselwithout any portion of the no::le proectin$ into the shell?

Answer: Ees, with "any restrictions

66. !plain the difference between a )F1 llipsoidal head and a he"ispherical head?

Answer: A he"ispherical head has no flan$e and 8nuc8le re$ion and holds $reater olu"e.

6+. *hich of the aboe two heads $ien equal thic8ness can withstand $reater internal pressure?Answer: #he )F1 elliptical head can withstand "uch "ore internal pressure $ien equal thic8ness.

6-. In A ection 3III, Diision 1, 'arts tolerances.

+. ea"s, holes, $aps, "issin$ ite"s, looseness of hardware in trays

-. ;ea8a$e #ests as needed for trays, trou$hs, weirs, etc.

/. Binal Cleanliness of #ray Asse"blies

64. *hat A'I docu"ents apply to the replace"ent of an e!istin$ floor for an Aboe$round il tora$e tan8?

Answer: A'I /-6 & A'I /-9

65. *hat are two 8ey ite"s to be resoled prior to addition of new no::les to older tan8s per A'I /-6?

Answer: #an8aterial identification, aterial Desi$n Considerations & selection (need for shellinsert%.

67. riefly describe an area i"pressed Cathodic 'rotection yste"?

Answer: lectrical current & use of selectiely placed sacrificial anodes is e"ployed to stop>slowthe electroche"ical reaction that occurs durin$ the corrosion process.

+9. elatin$ to Contractor *eld hop ealuation prior to the be$innin$ of pipe weldin$ for a "aor proect,what are seeral 8ey ite"s you would loo8 for as the Inspector assi$ned to approe the shop for Co"pany?

Answer: $M % " formula G anpower, ethods, aterials, achines, easure"ent, niron"ent

1. anpowerGnsure adequate 'ersonnel that are trained, qualified, certified & approed

). ethodsGnsure that standards are followed and that weldin$ procedures, special processes('I, '*0#, etc% are acceptable and that there is a $ood quality syste" (paper trail% in place.

6. aterialsGnsure aterials are approed, certified, docu"ented (traceable%, stored correctlywith area for deficient ite"s (quarantined%, and se$re$ation of dissi"ilar "etals.

+. achinesGnsure quip"ent is adequate for the intended wor8 and in $ood wor8in$ condition.


13/23

-. easure"entGnsure Contractor QC 'ro$ra" & testin$>calibration pro$ra" is in place forequip"ent and wor8.

/. niron"entGnsure that the wor8in$ eniron"ent (buildin$% is safe, sheltered fro" theele"ents and adequate to ensure quality wor8.

'er A*911 (show section where infor"ation is found, reiew with candidate%

1. *hat is the "a!i"u" si:e of low 0ydro$en (4915% per"itted?

). *hat are the dia"eter li"itations (per pipe si:e% for different weldin$ processes?

A*G

=#A*G

=A*G

6. a% *hat is the require"ent (aterial, location% for brid$e tac8s?

b% In what "ust brid$e tac8s be contained to aoid the need for urface ethod @D#?

+. a% Bor te"porary supports and attach"ents welded to the pipe, what are require"ents related toaterial?

b% @D#?

-. *hat is the "a!i"u" a"ount of ti"e that 4915 electrodes can be 8ept out in the field?

/. *hat is the "ini"u" dryin$ te"perature and dryin$ ti"e?

4. 0ow "any ti"es can electrodes be reba8ed?

5. *hat is the "a!i"u" internal "isali$n"ent of butt oints?

7. 'ipin$ durin$ preparation before fit up shall be cleaned>$round internally>e!ternally for whatdistance fro" the ed$e of the prepared oint?

19. oist surfaces require "oisture re"oal and surfaces to be preheated "ust be preheated to whatdistance fro" the oint ed$e?

1.Which of the following is fully killed steel?a)ASTM A 53b)ASTM A 10c)ASTM A 333d)All of the abo!e

Ans. b

".What is the #ill$s tole%ance to be conside%ed fo% the thicknesscalculation of s#ls &i&e as &e% ASM' (31.3a)1"b)1"."5

c)1".5d)one of the abo!e

Ans. c

3.(utt welded fittings *u&to 00+) a%e gene%ally used in which Si,e %angea)1-" / abo!e

b)" / abo!ec)(oth a / b


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d)one of the abo!e

Ans. b

.ASM' (1.10 desc%ibes about

a)ace to face / end to end di#ensions of non2fe%%ous !al!esb)ace to face / end to end di#ensions of fe%%ous !al!esc)(oth a / bd)one of the abo!e

Ans. b

5.ASTM Std. fo% .S welded &i&e isa)A10 4%.(b)A53 4%.(c)A6 57 4%.(

d)All of the abo!e

Ans. b

.ASTM Std. fo% 8 .S 150+ flangea)A"34% W(b)A"14% W(

c)A105d)one of the abo!e

Ans. c

9.:sually the ASTM Std. fo% 30 7.T..S. 'W &i&e isa)A333 4%.

b)A10 4%.(c)A91 4%.0 l.3"d)All of the abo!e

Ans. c

8.Which of the fluid Se%!ice is non2to;ic in natu%e?a)atego%y .All i&e bends in S a%e a)hot fo%#ed


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b)cold fo%#edc)both a / bd)none of the abo!e

Ans. b

10.What is the Si,e %ange in S fo% ASTM A10 S#ls.i&ea)1-8 to b)1-8 to c)1-8 to 8d)one of the abo!e

Ans. c

11.What is the d#n.std. fo% S.(. gate !al!e?a)A620"

b)A6200c)A620>d)one of the abo!e

Ans. a

1".What is the d#n.std. fo% 7.(. gate !al!e?

a)A620"b)A6200c)A620>d)one of the abo!e

Ans. b

13.What is the d#n.std. fo% S.(. globe !al!e?a)(S25351b)(S2535"c)(S21893d)A620"

Ans. b

1.What is the d#n.std. fo% 7.(. globe !al!e?a)(S25351b)(S2535"c)(S21893

d)A620"

Ans. c


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15.What is the d#n.std. fo% check !al!e?a)(S2535"b)(S2188c)(S21893d)(oth a / b

Ans. d

1.What is the d#n.std. fo% (all !al!e?a)(S25351b)(S2535"

c)(S21893d)one of the abo!e

Ans. a

19.Stea# &i&e lines a%e usually a)'@Wb)'Wc)Sea#lessd)one of the abo!e

Ans. c

18.7ow te#&. ca%bon steel shall be used below which te#&. in 0a)2"0b)230

c)2">d)20

Ans. c

1>.What is the std. used fo% Welded and sea#less w%ought steel &i&e?a)ASM' (3.10b)ASM' (3.1>

c)ASM' (1.11d)ASM' (1.>

Ans. a

"0.S#all bo%e fitting a%e co!e%ed unde% which A#e%ican std.?a)ASM' (3.10

b)ASM' (3.1>c)ASM' (1.11d)ASM' (1.>


17/23

Ans. c

"1.7a%ge bo%e fittings a%e co!e%ed unde% which A#e%ican std.?a)ASM' (3.10

b)ASM' (3.1>

c)ASM' (1.11d)ASM' (1.>

Ans. d

"".Which Std. is used fo% la%ge dia. flanges ?a)ASM' (1.5b)ASM' (1.9c)ASM' (1.8d)one of the abo!e

Ans. b

"3.is used as the fitting #ate%ial in 7TS fo% Si,es usually " /abo!ea)ASTM A"0 4%.W7b)ASTM A350 4%.7"

c)(oth a / bd)one of the abo!e

Ans. a

".is used as the fitting #ate%ial in 7TS fo% Si,es usually11-" / below

a)ASTM A"0 4%.W7b)ASTM A350 4%.7"c)(oth a / bd)one of the abo!e

Ans. b

"5. is a non2%etu%n al!e.a)4ate al!eb)4lobe !al!ec)(all al!ed)heck al!e

Ans. d

".What is the d#n.std. fo% lug !al!e?a)(S2535"


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b)(S25351c)A625>>d)A620"

Ans. c

"9. is the #a;i#u# te#&. till which a%bon Steel can be usedas &e% (31.3c)"50

Ans. c

"8. is the #ini#u# te#&. till which a%bon Steel can be usedas &e% (31.3d)2">0

">.:nde% which & g%ou& is a%bon Steel onside%ed?

a)1

30.4ene%ally is used as a by2&ass al!ea)4ate al!eb)(utte%fly al!ec)(all al!e

d)4lobe al!e

Ans. d

31.Ty&es of (all al!eB

a)ull o%tb)@egula% o%t

c)Soft Seat / Metal Seatd)All of the abo!e

Ans. d

3".Ty&es of heck al!eB

a)7ift ty&eb)Swing ty&ec)Wafe% ty&ed)All of the abo!e

Ans. d

33.4ate / (all al!e a%e !al!esa)6solatingb)@egulatingc)on2%etu%n


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d)one of the abo!e

Ans. a

3.4lobe al!e is a !al!e

a)6solatingb)@egulatingc)on2%etu%nd)one of the abo!e

Ans. b

35.What is the #ini#u# thickness %eCui%ed fo% S &i&e which needsW=T %eCui%e#ent?c)1> ##

an you explain in detail three or more major differences between code ANSI B31.1

and code ANSI B31.3?

Answer !here is only one major difference between the two" B31.1 is for #ower

#ipin$ and B31.3 is for %efinery&'hemical #lant #ipin$.

(. !here is a power plant inside a #rocess refinery. )here exactly the ANSI B31.1 *

ANSI B31.3 scope brea+ occurs?

Answer Based on my experience there were two cases. 'ase ,1" B31.1 stopped at the

#ower #lant -nit bloc+ ales. !hus all pipin$ inside the #ower #lant was B31.1. 'ase

,(" B31.1 stopped at the e/uipment 0Boiler isolation bloc+ ales and then all other

pipin$ was B31.3. !his is normally the choice of the owner&operator&client.

3. )hich of the followin$ pipin$ system is more health ha2ardous. A uel oil pipin$

b #rocess pipin$ with 'austic c process pipin$ with 4 acid d Sulphuric acid

pipin$.

Answer c process pipin$ with 4 acid

5. !here is a steam pipin$ with low poc+et but without steam trap. )hat will be

worst conse/uence of this layout?


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Answer !here will be a build up of condensate to the point that a slu$ will be pushed

by the steam flow. !his slu$ of condensate will cause 6water hammer7 and could rip

the pipin$ apart.

8. In what circumstance" the reducer of a pump suction pipin$ will be in bottom flatposition. 9xplain why the reducer should be so.

Answer )hen reducers are placed in pipe %ac+ they are $enerally bottom side flat to

maintain B:# to facilitate supportin$. 0Answer 'redit Samir ;umar

as+et and bolts from the SS spec.

. A stainless steel pipin$ specification mentions >alani2ed carbons steel bolts.

)hat is your first reaction ti this and how do you rectify it?

Answer If that is what the Spec call for then that is what I am supposed to use. But" I

would as+ the #ipin$ @aterial 9n$ineer 0#@9 why he&she specified $alani2ed

bolts.

. 4ow many types of pipin$ specialty items do you +now? )hy it is called a pipin$

special? )hy not we include them in standard pipin$ specification.

Answer I could possibly count 8 or more dependin$ on the #@9 and how the

pipin$ material specs were deeloped. !hey are called them S# items because they

are N:! written into the normal #ipin$ @aterial 0Cine 'lass Specifications. !hey

are not included because they are normally of limited use" purchased from a limited

product line endor and are often after thou$hts.

D. =raw a typical steam trap station layout and explain why the existence of a byEpass

line around the trap is not a $ood idea" when the condensate is returnin$ to a

condensate header?

Answer 0No drawin$ It is not adisable to hae a bypass around a steam trap

because the bloc+ ale could be left open and defeat the purpose of the trap.


21/23


22/23

Answer I a$ree. If they are all the same then the hoses can be connected to the

wron$ serices and could result in the injury of an operator 0i.e. thin+in$ the hose is

connected to water when it is connected to steam.

18. )hat is your iew on the usa$e of @etallic expansion joints? )hen they becomenecessary and when they could be aoided?

Answer I do eerythin$ I can as a pipin$ desi$ner to aoid the use of all types of

expansion joints. 9xpansion joints are always the wea+est point in any system where

they are used.

1


23/23

1D. A air fin cooler 0( air coolers with each hain$ ( inlet no22les needs a !ypical

pipin$ arran$ement. 4ow many types of pipin$ arran$ement is possible.

Answer !here are a number of ways to pipe a inEan cooler dependin$ on what the

#*I= call for?

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