4. An engine room should be ___________ for better performance of turbochargers.
A.Slightly under pressurized
B.Slightly Over pressurized
C.Substantially under pressurized
D.None of the above
34. You must have worked with mooring winch and windlass hydraulic systems. The cooling of hydraulic oil for the above system on large merchant ships is provided by:
A.There is no cooling arrangement as the system doesn’t require cooling
B.Air cooled hydraulic reservoir
C.Water cooled plate or shell type heat exchangers
D.Radiator and fan arrangement
124. Which of the foll. Conditions can cause above normal air temp. to develop in the intake Manifold of a four stroke/cycle, turbocharged, diesel engine?
a.clogged air intake filters b.Piston blow by
c.A defective after cooler d.faulty exhaust valves
205)When specified discharge pressure is not achieved, the possible cause could b?
a.Discharaage pressure too high
b.Pump speed too low
c.Casing ring is worn out
22.) Air is removed from refrigeration system by (1) PURGINGat receiver after (2) Cooling(3)collectingGas in receiver. Humidification is process of adding water/moisture to discharged airof AC blower. Dehumidification is process of removing water/moisture from air supplied from AC system. For collecting gas in receiver you need to close the outlet valve of receiver with compressor running
9.Throttling of discharging v/v of pump NPSHr will a.increases
b.decreases c.remain same
d.increased than NPSHa
218)Types of corrosion in fresh water of D/E
d.selective phase corrosion
41.A refrigerant compressor will run continuously when there is(single ans)
A.Too heavy cooling load on the system
B.Air in the system
C.Insufficient refrigerant in the system
D.Any of the
169.It is given that engine room bilge pump has suction manifold on which 3 valves are located. One valve for the 3 engine room bilge wells suction, another one for Bilge tank suction and the third one will be for
A.Fresh water suction
B. Cargo hold bilge suction C. Sea water suction
D. Waste Oil tank suction
195.Which of the following types of damages are metal seatings of a valve subject to?Choose the correct alternative.
A. Corrosion, Erosion, Abrasion, Deformation
B. Corrosion, Fatigue failure, brittle fracture, caustic cracking
C. Erosion, caustic cracking, brittle fracture, Cloverleafing
D. None of the above
208.Bronze is an alloy typically consisting of :-
A. Copper , lead & tin
B. Copper , Zinc & lead
C. Copper , Zinc & Tin
D. Copper , Tin & Lead
253.During stripping operation the discharge valve is kept throttled to maintain sufficient back pressure, why?
A.To avoid back flow of sea water into the ballast tank
B. If back pressure is not sufficient, the ballast water cannot be pumped out as the sea water head on the outside is more
C.To avoid pump losing suction due to loss of priming as the available suction head is very low =answer
D.To control the motor current which will otherwise be very high
136)Ship is in dry dock , stern tube seal renewal has been carried out, hw wl check For leak
a.Fill the system with oil to max. level in header tank
b.Fill the system with oil to just fill stern tube
c.Fill the art seal n forward seal tank to deepest draught
d.Refloat vessel to check for any leaks
220) which of the following is false statement abt galvanic corrosion?
A metals close to anodic end of the series corrode in pref to those near cathodic end B when single metal exist in the sys galvanic corrosion doesn’t take place
C zn is anodic to steel and used as a protective coating D corrosion rate is affected by temp.
221)Chromium is a nobler metal when compared to that of steel . In some marine applications Chromium is electroplated to the steel surfaces . Why?
A.Chromium is a more noble metal so it will not get corroded and thus steel surfaces will remain protected
B.Chromium plating provides corrosion protection as well as high glo nssiness and high hardness for better wear resistance and reduced friction to the steel surfaces
C.Chromium plating is required for providing high glossiness and high hardness for better wear resistance and reduced friction to the steel surfaces and not for corrosion protection
D.Chromium reacts with steel to form an alloy during electroplating which is corrosion resistant (majority)
Cavitation affects disch pr, pp power, pp revolutions. (discuss)
223)impingement corrosion can be best avoided during pipeline sys design by A keeping flow velocities to a min
B keeping fluid temp low
C avoiding conditions leading to cavitation and turbulence D keeping working pressures high in the system. (majority)
224) HSS are
A high carbon steels with suitably added alloying elements
B medium carbon steels with suitably added alloying elements C low carbon steels with suitably added alloying elements
D none of the above (majority)
225) nr vv of msw pp is leaking in closed position. U have a return type of vv onboard of same dimension. What wil u do?
A do nothing and run same pp order for a new one.
B replace and run the same pp keeping the other stby until new vv arrives. C put blank on the vv and run other pp.
226)which of the following options give u the correct sequence of the metal/alloys in decreasing order of preferential corrosion?
A stainless steel, naval brass, al bronze, cu
B al bronze, cupronickel, monel metal, titanium.
C stainless steel, cupronickel, naval brass, monel metal D st. steel, cu, naval brass, al bronze.
Some left questions
A.Appropriate tightening torque of the valve spindle
B.Gate and valve seat have a taper and when tightened they will seal against each other
C.Either the seat or the disc Gate are
D.For a gate type valve the sealing is never perfect and they always allow some leakage
11. Refer cooling tubes act as
131. sewage air compresser freq of starting
a)every 18 hur b)every 24 hr c)continously d)once in two week (sure)
140)The amt of current reqd for iccp depends upon A wetted surface area
B quality and condn of protective paint coatings C speed of the ship
D sw temp.
( few ppl with abcd.)
197)33. Ballast pump injection filter was cleaned n the pump was lined up it was found that there was some leakage in the suction filter suction. The pump started n the leakage started. During deblasting it was found that the pump could not take suction fr one of the double bottoms. The cause could be
A)Pump was drawing air fr.
B)Pump was drawing air fr suction filter
C)One of the pipelines on the suction side of the pump might be leaking
D)The filter was not cleaned properly.
208)In refrigeration system vegetable room n meat room r maintained at different
b.By putting solenoid valves
c.By boiling refrigerant at different pressures (sure)
d.By using smaller evaporator
126. When steel components electroplated with chromium r used in corrosive environment a.Chrome plating prevents corrosion
b.Protection to the steel wl b preferentially corroded
c.zinc plating is used on top of chrome plating for corrosion protection d.Thickness of chrome plating to increase
94)sudden opening or closing of sea water pipe can cause
THROTTLNG OF SUCTION V/V OF SCREW P/P?? A)alter dicharge capacity
b) no alter discharge capacity c ) alter fluid density
d) alter fluid pressure & density
135Why are large centrifugal pumps started with their discharge valves closed?(if single thn go with c)
A.To ensure proper priming
B.To limit sudden rise in discharge rate
C.To limit motor starting current
D.To minimize starting torque on motor shaft
142)Wat cud b the reason if feed pp can hardly pp in water to the auxillary blr causing cascade level to rise and temp too high??not sure
A high ambient temp
B clogged condense water tubes
C filter dirty
D low cascade water level.
163.The steels with a carbon percentage close to 0.8% have
A.poor strength but good weldability
B.High strength but poor weldability
C.Poor strength and poor weldablity
D.High strength and good weldability
57.WHICH PROCESS IS NOT DONE ON MILD STEEL ..????
C. explosion bonding,
D. metal spraying
3.Which of the following is NOT a correct point for sampling of system lube oil for on board or shore analysis? (Sure ans)
B. Purifier outlets
C. Inlet or outlet of L. O. coolers D. Tank drains
4.The ballast valve of the fore peak tank is located in the duct keel and cannot be opened or shut by remote operation. The valves of other tanks can be operated remotely without any trouble which of the following will be the best practice? (sure ans)
A. Valve should be checked locally for troubleshooting without which it is difficult to find the exact problem
B. The actuator must be defective and should be replaced with a new one C. The control circuit is defective and the PCB should be replaced
D. Shore assistance will be required in such cases
5.Pump Start But Motor gets overloaded or Trip on overload. ( multiple answer)
A.Alignment is wrong
B.Gland packing too tight
C.Worn out / Damaged ball bearing
8. When running TWO centrifugal Pumps in parallel, Flow rate "Q" is increased. (sure ans)
D.I Don't know
10. Normally so called single screw pumps are used as sludge pumps in engine room. What is the correct technical name of these pumps?
C.Progressive cavity pump
13. Copper tubing is used in refrigerant system because
A)It has less internal resistance
B)It is cheaper compared to other materials.
C)It is easier to check leaks in copper based system D)None of the above
15.While refloating the vessel after dry docking which of the following check should be Carried out
A)Sounding of all double bottom tanks
B)Checking leakages in the stern tube header tks
C)Checking leakages of shipside valves
D)Checking level of stern tube, header tanks
11.NPSH and the Total suction head are two terms which are commonly used for pumps. Which of the following is a true statement?
A.They are one and the same thing
B.Total suction head is greater than NPSH
C.NPSH is always greater than Total suction head
D.Total suction head and NPSH have no relationship
7. During flooding of a dry dock the following items must be verified
A.All sea valves are operational
B.All overboard discharge valves are operational
C.Stern tube seal are operational
D.All of the above
9. In which of the following types of refractory failure, softening of the refractory bricks takes place due to presence of sodium/vanadium in fuel?
12. Which of the following V/V cannot be overhauled in place without removing piping? A) Ball Valve (B) Diaphragm valve
C) Globe valve (D) Butterfly valve
16. Why should only approved toilet cleaning chemicals be used in
A)Unapproved chemicals can lead to corrosion in the system
B)unapproved chemicals can lead to toxic conditions in the system leading
C)To destruction of protective coatings
D) Unapproved chemicals can kill aerobic bacteria making the plant ineffective Gases produced by use of unapproved chemicals can pose threat to the operatorsv
17)After ofver hauling reciprocal pump the motor connections were wrongly given. Determine outcome when pump is started? (Sure ans wid majority)
A) The direction of flow wl remain unaffected B) the direction of flow wl b reversed
C) The pump wl get damaged because the suction valve wl block the reverse flow causing overpressure leading to pump breakdown.
D) The pump wl lose suction N there wl b no flow.
18)Pump driven type clutch attached to vacuum pump r commonly used for
priming ballast pump n emergency fir pump. What is the factor which clutches the vacuum pump to pump the clutch during start of the pump.
A)Low suction pressure acting against the spring loaded clutching piston
B)High suction pressure actiong against the spring loaded clutching piston
C)Low discharge pressure acting against the spring loaded clutching piston
D)High discharge pressure acting against the spring loaded clutching piston
20.A thin layer of electrolyte trapped in a small pits on a metal surface , and remaining stagnant over a period of time , may cause :
B. Bimetallic corrosion C. Crevice corrosion D. Corrosion
21.The purpose of an evaporator in the domestic refrigeration system is to
A.Transmit latent heat of evaporation
B.Absorb latent heat of fusion
C.Absorb latent heat of evaporation
D.Transmit latent heat of fusion
23. Which of the following statements is False about cleanliness of electric motors?
A.External motor body cleanliness of totally enclosed is important since the body helps to dissipate heat generated
B.Dirt, oil, grease and moisture are primary culprits in deterioration of insulation of stator windings of a motor.
D.Dry compressed air at a high pressure can drive in dirt inside windings instead of removing them
24.The attached vacuum pump of a ballast pump operates on the principle of a: A. Centrifugal pump
B. Reciprocating pump C. Gear Pump
D. Vane Pump
25.Increasing the rotational speed of a cargo pump the pump flow rate will:
A.Increase in direct proportion to the increase in speed
B.Decrease in direct proportion to the increase in speed
C.Flow rate doesn't depend upon speed
26. Vacuum priming pumps which work on the principle of fixed vane pumps require _____________
for___________ clearance between vane tips and casing.
A.Lube oil, lubricating
B.Lube oil, sealing
D.Gland packing, sealing
27.Which one of the following is a type of corrosion :- A. Electroplating
B. Galvanisation C. Graphitisation D. Demulsification
28.The main disadvantages of a reciprocating pump over a Gear pump is that: A. A gear pump is self priming while a reciprocating pump is not
B. Discharge of a gear pump is not affected by the direction of rotation while that of reciprocating pump is reversed
C. The discharge of reciprocating pump is pulsating and discharge rate is lesser
D. Reciprocating pumps are only available in high capacities and for smaller capacities only gear pumps can be used
29.When centrifugal pump is used to pump a liquid of higher specific gravity the pump Power will
C.Will not be affected as the pump power depends only on the flow capacity
D.None of the above
30)shaft sealing of a main sea water pump for ship plying in coastal muddy waters, which is the best option
B.Lip seal with garter spring
32)removable sleeves on centrifugal pump shaft:
a)make easier to replace pump shaft packing
b)they can be economically replaced as they wear out
c)to lighten weight of pump
d)increase strength of shaft
33)A recently completely overhauled Engine room bilge pump was working efficiently. Suddenly one day you find that the pump is not taking suction.
You have tried priming with sea waterbut still the pump doesn???t take suction from any of the bilge wells or bilge tank.
What could have gone wrong inside the pump? Choose the best alternative.
A.The bucket rings have worn out
B.The suction or discharge valve must have worn out and started leaking
C.The suction or discharge valve might be stuck in one position or some debris mighthave lodged itself
in between the valve and the seat
D.Pump suction filter might be clogged
34)air compressor cooler tube type(doubt) a)spring tube
c)fix tube d)u tube
36)Which of the following option gives you the correct sequence of the metals in decreasing order of preferential corrosion when all of them are bonded and immersed in an electrolyte ?
A.Titanium, Mild Steel , Zinc , Stainless steel
B.Titanium , Stainless steel ,Mild Steel ,Zinc
C.Zinc , Mild Steel , Stainless steel , Titanium
D.Zinc , Titanium , Mild Steel , Stainless steel
39)The lower half of main bearing of a very large diesel engine can be removed by:
A.Pulling out with a chain block
B.By hammering out with the help of a soft mallet
C.By slightly jacking the crankshaft and turning out the bearing half with a rope or similar tackle provided.
D.By using a special tool in the oil hole and turning the shaft to turn out the lower half.
40) pl answer the following question.
Purifier leaking bowl opened, cleaned n seal ring changed n putback bt still leaking wat might b wrong
c.disc size nt proper
41.Surface preparation of steel surfaces, prior carrying out painting isimportant because (choose the best alternative):
A. Any rust and contaminant inclusions may cause local paint film breakdown B. Too much paint will be consumed if surface preparation is not carried out C. Surface will be very rough if proper surface preparation is not carried out
D. Surface preparation deposits a chemical onto steel surface which reacts with paint film and causes strong bonding
42.Accelerated corrosion due to removal of protective surface films (e.g.) oxide layers on metal/alloy surfaces due to turbulence of working fluid is known as
a) Bimetallic corrosion
b) Impingement corrosion c) Cavitation erosion
d) Selective phase corrosion
44)In shell and plate type coolers, due to improper flow design or partial blockage of tubes may lead to high turbulence locally. This condition may lead to (choose the best alternatives):
B.Selective phase corrosion
(multi then c n d. single choice d)
45)You have overhauled a centrifugal pump and while assembling forgot to install the
A.It will not affect the pump in any way
B.It will cause leakage of fluid(air/water) in between the shaft and the sleeve and will affect the
C.It will not affect the pump performance n any way but will corrode the shaft between the
D.It will cause dynamic imbalance of the shaft
46)Which of the following is a true statement ? (choose more than one option if true)
A.Mild steel will be subject to preferential corrosion when in electrical continuity with stainless steel in presence of an electrolyte
B.Stainless steel will be subject to preferential corrosion when in electrical continuity with Mild steel in presence of an electrolyte
C.Copper will be subject to preferential corrosion when in electrical continuity with Mild steel in presence of an electrolyte
D.Zinc will be subject to preferential corrosion when in electrical continuity with Aluminium in presence of an electrolyte
47)boiler pp operate at an elevated temp and pressure. The ideal materials for the pp casing and impeller shud b
A gunmetal casing, al bronze impeller
B high gade CI casing, bronze impeller
C cast steel casing, SS impeller
D cast steel casing, al bronze impeller
49)screw pump is generally are ??????????????? pump
b.high speed c. medium speed
d.all of the above
50)the gland packing of centrifugal pump
a)should not allow any breakage under the suction pressure.
b)should only allow drop by drop continuous leakage under positive suction pressure.
c)should only allow drop by drop continual leakage under positive suction pressure.
d)should allow considerable leakage
53). Corrosion protection of steel surfaces by zinc coating can be carried out only at temperatures below 65 deg. C. For higher temperatures..
a)Zinc reacts very fast and thus can only provide protection for a limited time
b)Zinc reacts with steel and protective layer vanishes due to chemical reaction
c)Steel may corrode preferentially to the zinc
d)Dezincification occurs leading to removal of zinc coating
(Reference http://www.ingal.com.au/FAQ/faq24.html written clearly here that reversal of polarity takes pace at temp more than 70 deg.)
59) Which of the foll. is a true statement
A) Aluminium will b subject to preferential corrosion when in electrical continuity with stainless steel in presence of an electrolyte.
b) Stainless steel will b subject to preferential corrosion when in electrical continuity with mild steel in p resence of an electrolyte.
C) Copper will b subject to preferential corrosion when in electrical continuity with stainlesssteel in presence of an electrolyte
d) Aluminum will b subject to preferential corrosion when in electrical continuity with zinc in presence of an electrolyte
60)main engine is running but viscosity of fuel cannot be maintained.fuel oil heater have a maximum rating of 4 bar steam pressure.steam through a pressure reducing valve is provided to the heater at 4 bar but still viscosity of fuel annot be brought down below 20 cst. as a good marine engineering practice what will you do?
a.let the engine run at same rpm n wait for the port to come to carry out the cleaning of heater
b.reduce the rpm till next port arrives n then clean the heaters
c.increase the steam pressure by adjusting the setting of steam reducing valve
d.stop the engine n clean the heaters
one more option Reduce the load and run the engine till weather becomes normal
62)Most steam traps respond well to cleaning. But when a thermodynamic trap fails to operate after cleaning, the next course of action should be:
Throttle the steam outlet valve
Renew the trap
Lap the disc and the seat of the trap
Throttle the steam inlet valve
56)Cadmium coatings provide corrosion protection . Cadmium coatings are commercially carried out using which of the following methods :-
63. Resistance to corrosion of Aluminium alloys is due to :
A.Aluminium being a very noble metal when compared to other metals in Electrochemical series
B.Formation of Aluminium oxide(Alumina) passive film on surface
C.The rate of corrosion is very low due to very high corrosion potential
D.All of the above
64)Fuels as produced in a refinery are generally sterile, however, contamination can occur as fuels are
A.stored at the refinery B. stored on the vessel
C.transported to the distribution sites D.All of the above are correct
67)During prolonged astern manoeuvring of the relative expansion between any of the turbine its casing is likely to increase for an alarming level you should (multi choice)
A)Inform the bridge that no further manoeuvring is possible as the turbine are likely to be damaged
B)Reduce the vacuum further to control the relative expansion
C)Keep manoeuvring irrespective of damage to the turbines
D)Request the bridge to try to reduce number of astern movements
68)If three Centrifugal pumps are running in parallel and the backpressure is substantially increased, what effect will be observed on the pumps in use.
A.Flow rate will reduce.
B.Increase in the pump casing temperature.
C.Safety alarms and trips (high casing Temperature) will activate, if no corrective action taken
D.None of the above.
E.All of the above
69.Before putting into operation a coalescer type Oily Water Separator, it is important to:
A.Fill it up with purge water
B.Drain it completely
C.Switch off the heater
D.Keep the three way valve manually open
70.The water from discharge side of the a centrifugal pump is supplied as sealing water to the stuffing box for the pump shaft at:
71.Process of enrichment of surface of steel and steel alloys by zinc using Electroplating is known as
72)Which of the following will be required to be done in order to reduce sulphur corrosion of Main Engine components
A.Increasing the atomization pressure of fuel injectors
B.Fitting exhaust valves with valve rotators
C.Running engine at or near normal sea load
D.Decreasing the F.O. purifier feed rate , running two purifier in series one acting as purifier and other as clarifier
74.If the direction of rotation of a gear pump is reversed due to change
A.Direction of flow remains the same
B.The pump will get damaged due to overpressure on suction side
C.Pump relief valve will be lifted
D.The direction of flow will be reversed
75.resistance testing should be ideally done on electrical equipment when the equipment is:
B.Hot or at working temperature
D.At part load
77.All other conditions remaining constant, when centrifugal pump is changed over for pumping a liquid of higher specific gravity, the discharge head of the pump at the rated capacity will
D.Can???t say, depends on other factors too
78.The process of depositing chromium on to steel surfaces by diffusion coating is known as :
81.When centrifugal pump is changed over for pumping a liquid of higher specific gravity which of the following is going to change?
80.For the S.W. side of a M/E L.O. cooler it is noticed that rise in S.W.temperature through the cooler has decreased from 12 deg. C to 7 deg. C over a period of time, while the drop in temperature of L.O. across the cooler has also decreased.All other coolers have been reported to be working normal & M/E is also running at a constant load in calm weather.What is the inference drawn by decrease in
the temperature difference?
A.The cooling S.W. inlet temperature has reduced
B.The efficiency of the cooler has increased over a period of time
C.The cooler has become dirty on the S.W. sideor L.O. side
D.S.W. side of the cooler may be partially blocked with mud and sea shells
6.The most important control measure to prevent boiler tube failure is: A. Use of proper refractory material
B. Proper maintenance of fuel burning equipment C. Proper maintenance of boiler water condition D. All of the above
84)A ball vv found leaking in service needs to be overhauled. What type of repairs can b carried out?
A the ball and seat can be lapped together
B the ball can be machined while the seat can be replaced
C normally both non metallic seats get wornout and have to be replaced
D normally ball gets damaged and has to be replaced.
86)It is a known fact that centrifugal pps require priing for pumping liquids, as they cant handle air and will lose suction due to air entry. But on the other hand t/cs use centrifugal compressors for supercharging. Which of the following do u think makes a centrifugal compr to pump air and behave differently than the centri. Pps?
A presence of air cooler
B presence of labyrinth seal
C high speed of rotation, very fine internal clearance and large impeller diameters.
D difference in the principe of operation.
A.Supply liquid even when the pump is not running
B.Dampen out the pressure pulses and smoothen the flow
C.Increase the discharge pressure by storing liquid under pressure
D.No such device is required to be fitted to modern bilge pumps
F.O. transfer pump was working efficiently, but it stopped taking suction suddenly. There is a sounding of 6.0 m in the F.O. deep tank. The suction pressure gauge was renewed recently and is showing a positive pressure whenpump is running, but Pump is not transferring any F.O. What is the most probable cause?
A. Pump is damaged and needs overhaul
B.Suction filter cover gasket might leaking
C.Pump relief valve might be leaking
D.The pump suction pipeline is blocked
90) you must have used rubber reinforced joints. The reinforcement is normally provided using non asbestos fibres. The reinforcement is provided because
A ordinary rubber gasket has porous matrix. Having capillaries which can allow liquid leakage when subjected to high pr.
B to increase load carrying capacity of the joint so it can withstand high pr. C to incr temp resistance of joint
D to protect the joints from fire or other accidental damage.
91.Which of the following can lead to premature failure of roller bearings?
92)Static suction head of the pp is
a.distance of the suction liq lvl above the centre line of the pp
b.distance of the suction liq lvl below the centre line of the pp
c.force necessary to overcome frictional losses in the pp and piping
d.amt in inches of mercury the total suctn head is below atm pr.
* suction lift below centerline of pump
93) centrifugal pp will typically give u low flow rate at low pr. Where a piston pp wil give u more pr and high flow rate. Is the statement correct?
C1st one right 2nd one wrong
DI dnt know
96) which of the following is the material is used to manufacture tube plates of a shell and tube type heat xchanger?
A cupro nickel
B al brass
C admiralty brass
98)The common term used for failure of metal and alloys in a corrosive environment , when subject to high stresses is known as : majority
C.Stress corrosion cracking
A Bimetallic corrosion of brass and bronze alloys leading to deposition of graphite
b Selective phase corrosion of grey cast iron leading to corrosion of graphite flakes and leading to loss of strength
c Electroplating process in which graphite is deposited on the mild steel components to protect them against corrosion
d Chemical reaction between pure graphite and iron so as to increase the graphite content of iron (not sure
107. Reciprocating compressors lines are fitted with a _______ to keep the discharge free of pulses
d.Pressure reducing valve
108. Which of these not self actuating valves.
b.b. relief valve
c.c. ball valve
d.d. safety valve
106)sea water outlet temp. of a lube oil cooler decreases but inlet temp. remains same. load on main engine is also constant what can be concluded from this
a. decrease in cooler efficiency(Ans) b increase in cooler efficiency
c.decrease in lube oil temp.
d.increase in lube oil temp
111. Emergency fire pump has been lined up for supplying to fire hydrant on deck. As Soon as pump is started the vacuum pp engages. The suction of the pump goes into High vacuum but the pump discharge pressure remains zero, and the vacuum pump Doesn???t disengage ? What is the most probable cause for the pump not to take Suction?
a.The discharge pressure gauge is defective showing zero discharge pressure
b.The pump suction filter might be clogged
c.The suction pressure gauge is defective showing high vacuum
d.The vacuum pump is defective
112. Boiler not stating in
a.Check fuel ignition system
b.Check fuel burning system
115. The seating mtrl. For perfectly sealing type Ball Valves is usually made up of
b.PTFE or Nylon
C. Rubber reinforced with steel wire
d. Stainless steel b and c
114)Which of the following can be done to reduce the cold corrosion of Main Engine cylinder liners using high sulphur fuel oil :-
A.Increasing cylinder oil feed rate
B.Using high TBN cylinder oil
C.Increasing scavenge air temperature
D.Decreasing cylinder oil feed rate
127. Auxillary engine connecting rod bottom end bolts should be tightened
a.only as per prescribed torque using a torque ran
b.as per prescribed torque as well as angular measurements as recommended by manufacturers
c.by foll. Previous match marks on bolt heads n connecting rod body
d.as per prescribedtorque n another 10% increase during every subsequent tightening
(sure fb majority)
139)Before starting a centrifugal pp eith priming pp, it shud b insured that _____ is at the correct level.
A lube oil
B sealing water
C fuel oil
D sealing oil
151)A reciprocating pump is used for Engine room bilge service because:
A.Reciprocating pumps are designed for smoother discharge
B.Only small capacity pumping capacity is required, while other pumps are of higher capacity C.It doesn???t churn and mix the bilge water unlike other types of rotary and rotodynamicpumps
D.Shipbuilding industry is still going on old concept, future ships will have centrifugal pumps installed
147)In a sw cooled jw cooler the most common cause for loss of cooler efficiency is A scale formation on jcw side
B mud or slit deposits on jcw side
C scale formation on sw side
D none of the above 146)Carbon content in steel? A less than 1%
B less than 2 %
C less than 3 %
D any carbon content
154.Which of the following types of boiler burners have maximum turn down ratio?
A.Pressure jet type
B.Spinning cup burner C.Spill type burner
157)U have seen and operated several valves onboard ships. All the butterfly valve operation handles are operated by a locking arrangement because:
A.Butterfly valves do not used gland packings and thus spindle doesn???t have anything to keep it in position and can open by vibration
B.Butterfly valve does have a spindle packing but same cannot be excessively tightened to have good grip on the spindle to prevent it from opening against vibration
C.Butterfly valves can move by vibration but that is not the main consideration, the main consideration being opening/closing against liquid pressure
D.All the butterfly valves do not have locking arrangement as there is no such requirement for the
158)SCREW P/P NORMALLY USED FOR A.FLUID WITH HIGH VISCOCITY
B.FOR BETTER PERFORMANCE AT VARIABLE TEMP. C FLUID MIXED WITH SOLIDS
D ALL ABOVE
159)CENTRIFUGAL P/P REQUIRED PRIMING BCOS THEY UNABLE TO HANDLE A VOLATILE LIQUID
B HIGH TEMP LIQUID
C LIGHTER LIQUID
D AIR & GAS
160)WHENTWO DISSIMILAR METAL HAVING ELECTRICAL CONTINUITY ARE PLACED IN ELECTROLYTE THE TYPE OF CORROSION
A SELECTIVE PHASE CORROSION
B CAVITATION ERROSION
161) CAVITATION OF CENTRIFUGAL P/P
Ctotal suction head<NPSHr
DTOTAL SUCTION HEAD> NPSHr
164.Which of the following cannot be used as sacrificial anode for the protection of Mild steel structure against corrosion :
165.Excessive lubrication in compressors can lead to: multiple
A.Sticking of valves
B.Carryover and deposit of oil particles in pipelines and reservoirs
166.The pumps performance depends upon
A.Clearance between the wear ring and the impeller
B.Clearance between the impeller and the casing
C.Clearance between impeller and shaft
D.Clearance between mechanical seal and shaft
167)A multistage centrifugal pump is normally used
B.High discharge flow
C.High viscous fluids
D.Low viscous fluid
170. During auxiliary engine
A.Sounding of all double bottom tanks
B.Connecting rod big end ovality
D.Crack detection tests on connecting rod serrations
171.In a reciprocating pump the direction of flow depends upon:
A.Direction of rotation of the pump
B.Position & fixing of suction and discharge valves
C.High pressure to low pressure
D.Whether pump is single acting or double acting
172.Fire side in boilers gets commonly corroded due to :
B.Formation of Vanadium pentaoxide and sulphuric acid
174.During shutting down the purifier you find that purifier always vibrates heavily for some time and then becomes normal until it finally comes to a stop. What is wrong with purifier?
A.The purifier design is faulty
B.The purifier bowl has a heavy sludge deposit and requires cleaning
C.The purifier bowl is not balanced properly
D.During shutting down most of the purifiers pass through the critical speed zone
175.Which of the following can cause exhaust with black smoke in a diesel engine?multi choice
A.Choked air filter of turbocharger
B.Water mixed with fuel
C.Bad atomization of fuel
176).the purpose of the wearing rings used in a centrifugal pump is to
A.Prevent internal explosion in the pump when it is overheated
B.Enable a visual inspection of the pump when it is running
C.Ensure a proper alignment of the pump coupling to the driver
D.To isolate suction and discharge side
179)in impressed current cathodic protection system , the current for cathodic protection is supplied by :
a.use of sacrificial anodes
b.a low voltage dc supply
c.a low voltage a.c. supply
d.110 v a.c. supply
181)a centrifugal pump may fail to deliver water when first started if the _________.
a:water seal pipe is plugged
b:pump is not primed
c:seal ring is improperly located
d:impeller is flooded
184)you are pumping out sludge to a shore facility using your sludge pump. you find that the discharge rate of pump is very slow and suction filter is getting clogged frequently.what is the best alternative to counteract the problem? a.remove the pump suction filter and pump out the tank b. increase the tank temperature, keep an eye on the pump suction pressure and clean the filter as soon as it drops c. as soon as the as the shore facility tells you that they are not receiving any sludge, you stop the pump and clean the filter d. fabricate a bigger mesh size suction filter and use in place of normal filter so that frequency of filter blockage is reduced and you can get a better discharge rate
199) Super chlorinating of fresh water tanks in dry dock is done by:
A.Washing the tanks with 100ppm chlorine solution
B.Washing the tanks with 50ppm chlorine solution
C.Leaving a 50ppm chlorine solution in the tank for 4 hours before flushing with clean water
D.Leaving a 50ppm chlorine solution in the tank for 24 hours before flushing with clean water (sure ans ref mcgeorge)
202) Which of the foll wl cause cavitation
a.Low discharge pressure
b.Throttling the suction valve
c.Low water level in the wet well
d.High discharge pressure
82. use of synthetic polymer treatment limited to low pressure boiler why(correct)
b- does not prevent the sludge formation
c- does not have po4 to tackle caustic embrittlement d- all of the above
83.auxiliary engine crankpin bearings are normally renewed.
d.after checking the bearings weardown
A.Fuels containing vanadium content with high sodium content are used
B.Fuels containing vanadium content with low sodium content are used
C.Fuels containing high vanadium and high sulphur content are used
D.Fuels containing high sulphur content is used and the exhaust temperatures are uncontrolled and exceed 600 deg. C
105.Cladding is the process used for :-
A.Protection of metal surfaces against corrosion
B.Protection of metal surfaces against erosion
C.Protection of metal surfaces against cavitation erosion
D.Protection of metal surfaces impingement corrosion
104- Metal cladding provides protection to the metal essentially for the life of ship because
A.During cladding the protective coating reacts chemically with the base metal and inhibits corrosion
B.This is the only method in which the completeness of the metal coating can assured, while other methods are liable to defects
C.The thickness of protective coating is greater compared to any other metal coating method used
D.The adherence of coating is best in case of metal cladding
109. When centrifugal pump is overhauled it was found that shaft had developed grooves on it n no spare is available onboard what action can be taken
a.Order a new spare
b.Assemble the pump without doing anything n wait for the spare to arrive.
c.Machine the shaft sleeve on lathe n put back the new packing.
d.Leave the pump as it is
117. Refer compressor oil should hv following properties:-
a.Chemically inert wrt refrigerant
b.Should b able to perform at lower temp (viscosity n cloud point)
c.Should hv a certain emulsification properties with water..
d.Should absorb water but still perform the lubrication
121. Dirty air filter on a Centrifugal Blower cause
122.____ Provide in protection against mild steel galvanic corrosion
119. Cavitation erosion occurs due to a. Chemical action b. Physical action
c. Chemical OR physical action d.Combination of chemical or physical action
123. 2. Fire p/p1 water to deck discharge pr 5 bar deck hydrant not getting water. Fire p/p2 discharge pr 2.5 gives water. Fire pump 1 unable to send water to hydrant. What is the reason?
a.Pump pressure gauge defective
b.Overboard discharge v/v fully opened so water is not going to deck
c.Pump suction filter choke
d.Pump discharge v/v may b stuck
125. Best sealing is which vv>?
130. What is the purpose of the Bypass valve ( Automatic or Manual operated) on the positive displacement pump?
A.Control the Discharge Pressure
B.Another valve provided for Discharging
D.I don't know
132.After removing all the bonnet securing nuts of a large size globe valve it is found that the bonnet is not coming out because of strong adhesion of the gasket between the bonnet and the body. What are you going to do in line with the best practices?(choose the best alternative)
A.A chain block can be hooked onto the handwheel and bonnet should be (freed out of gasket adhesion) lifted clear of the valve body
B.Hammer the valve bonnet and the bridge from all sides using a big hammer until the bonnet is free?????????
C.Use a hammer and chisel and try to force the chisel in, at the joint of bonnet and body equally from all the sides until the bonnet is clear ***
D.Try to close the valve disc further onto the seat by turning the handwheel in closing direction so as to ???
134)the crank web deflection readings of a diesel engine would be erroneous in which of the following conditions?
a.when the draught of the vessel has changed while readings were being taken
b.when ca rgo loading and discharging has been too rapid
c.when the crankcase temperature has changed substantially during the process of taking the readings (if single)d. none of the above
137)Corrosion resistance of ss in presence of o2 in aerated water??
A o2 inhibits chemical reaction.
B o2 combines with ss to form passive oxide layer
C o2 gets absorbed into ss.
162The corrosion protection for Cooling Fresh Water systems of Marine Diesel Engines is normally provided by :
C.Protective Metal coatings of system components
D.Addition of corrosion inhibitors to the Cooling Fresh water
169. A drain cooler is provided with S.W. cooling. What is the best way to increase the temperature of condensate draining to the hotwell?
A.Throttle the S.W. inlet valve
B.Throttle the S.W. outlet valve
C.Open the condensate Bypass to the cooler
D.Close the condensate bypass to the cooler
178)boiler corrosion is prevented above 100 deg by formation of a protective layer inside of
c.haematite d. iron sulphate
180) in a centrifugal pump discharge must be in the direction as that of
a.direction of vane curvature from eye to impeller
b.direction of vane curvature from impeller to eye
c.depends on shape of volute casing d.none of the above
186) which of the following statement is false abt galvanic corrosion?
a. metals close to anodic end of the galvanic series corrode in preference to ones close to cathodic end.
B when any single metal exist in the system it cant corrode due to galvanic action.
C zn is anodic to steel and is often used as protective coating
D corrosion rate is affected by temp
185)which of the following would be the correct way(s) of using a torque wrench? (mcq)
a.application of jerk pulls while tightening
b.using an extension
c.tightening beyond the characteristic clicking sound
d.none of the above
188)After cleaning the sea chest filter you have placed the filter in the body and tightened the cover. Which one of the following is the best alternative?
A.You can open the filter inlet and outlet valves & directly start using the filter
B.If you do not want to use the sea chest in question, you need not worry and you can open the valves when required
C.Sea Water inlet valve should be crack opened, the filter body should be purged, any leakages and thereafter filter can be kept isolated or used as required
D.You will close the other side sea chest valves first and then open this side sea chest filter inlet and
203)With ref. to centrifugal pump charac, what wl b the effect when p/p is started with Suc v/v closed or disc v/v closed:
a.Suc v/v shut head & flow rate wl be o; disc v/v shut flow rate wl b o n head wl b max. height.
b.Suc v/v shut head wl b o & flow rate wl b min , disc v/v shut flow rate wl b o head wl b min. ht.
c.Suc v/v shut head n flow rate wl be o; disc v/v shut flow rate wl b min n head wl b
At min ht d. None
210). For any p/p max. theoretical lift a. 10.5 ft b. 10.2 mtr. C. 10.5 mtr
d. 12.0 mtr e. none (mcgeorge given 10.3m)
209). The best way to clean compressor impeller of an auxiliary engine turbocharger would Be:sure
a.By soaking it overnight in a strong chemical solution like carbon remover or air Cooler cleaning chemical
b.By chipping the dirt off the impeller blades
c.By using a pneumatic wire brush
d.By soaking in warm water n then cleaning it gently by rags
Purpose of balancing hole on single entry enclosed type impeller of cf p/p a)static balancing of imeller
b)dynamic balancing of impeller
c)balance out axial thrust on the impeller & hence the shaft
d)to reduce weight of impeller at the same time of dynamic balancing the complte rotating assembly
219)Primary advantage of central cooling sys is
A more simplified cooling ckt
B most part of the clg sys being fresh water based, corrosion is minimized
C it allows better control of temp.by using fewer cntrollers
D all of the above(may be)
212)desludging seq for pfr???
A stop feed- give sealing water- close sealing wat- shut operating water- open and close desludging wat quickly
C shut operating water- stop feed- open seal water for short tym- close open and close desludging water
D shut operating water- stop feed- open and close desludging water quickly
206)Protection of zinc [rtective coating is good at a. 50 Deg. Cel. B. 65 c. 90 d 115
35)Which of the following option gives you the correct sequence of the metals/alloys in decreasing order of preferential corrosion when all of them
are bonded and immersed in an electrolyte?
A.Stainless Steel , Naval Brass , Aluminium bronze , Copper
D.Stainless Steel , Copper, Naval Brass , Aluminium bronze
55)After cleaning the M/E F.O. heater you have assembled the heater and want to try out the heater before putting into use. Which is the correct sequence of operation of the valves?
A.(1) Vent valve open (2) F.O. inlet valve crack open (3) When F.O. starts coming out of vent line close vent (4) F.O. inlet valve full open (5) F.O. outlet valve full open (6) Steam return and inlet valves slowly opened up
B.(1) Vent valve open (2) F.O. outlet valve crack open (3) When F.O. starts coming out of vent line close vent (4) F.O. outlet valve full open (5) F.O. inlet valve full open (6) Steam valves slowly return and inlet opened up
C.(1) F.O. outlet valve crack open (2) F.O. inlet valve crack open (3) As the pressure gauge shows pressure open steam heating valves slowly (4) Fully open F.O. inlet and outlet valves
D.(1) Open steam retur
58. You have started pumping out a Fore peak tank. The ballast pump is running showing a low discharge pressure but a positive suction pressure,Chief Engineer asks you to throttle the discharge valve to increase the back pressure on the pump. Why do you require to do the same?
A.The pump???s discharge rate needs to be controlled as it is pumping at a higher than rated capacity
B.Chief Engineer wants you to slow down as the deballasting is going on too fast and will finish sooner than expected
….C. It is a misconception that pumps operate smoothly at increased back pressure and throttling of the discharge valve is a wrong practice
D.Centrifugal pumps cannot operate at greater than rated capacity, so throttling the discharge valve is only going to decrease the discharge rate below rated capacity
76.Sherardising ,Chromising and Calorising fall under which of the processes of metal coating application :
85)A submerged type centrifugal pump is sometimes used as the Main L.O. pump. Why is this?
A.Flow rate required for Main L.O. systems are very high
B.The pressure required for Main L.O. system is high
C.It is a wrong design and such systems normally give problem
D.Both the pumps can be run together when the bearing temperatures are increasing
87. Which of the foll. Cannot b removed fr fuel oil by centrifugal in the purifier n micro filtration?
b.Aluminium n silicon
113. Sea chest is to b cleaned n u found that the filter is stainless steel bucket type filter, Inside which there is a zinc anode. The purpose of anode is to __________ and should b Electrically _________ with filter body.
a.Stainless steel filter, isolated
b.Mild steel body, continuous
c. Protect adjacent pipelines, continuous d. Seachest, isolated
128. which of the foll. R true as far as painting of steel hull/structure is concerned?
a.Painting can b done under any wether condition
b. Painting can only b done after proper surface preparation is carried out
c.painting should only b done on top of appropriate primer coating d.several coats of paint can b applied one after other without any time gap
129. Which of the foll. Is false about hydraulic jacks/tensioning tools?(single option thn d if mcq thn b also)
a.Piston of the jack should b turned back by a certain degree after hand tightening to prevent easy removal after untightening of nut.
b.Piston of the jack should not b turned back after hand tightening during untightening of the nut. c.Piston of the jack need not b turned back during tightening of the nut
d.Hydraulic pressure need not b relieved during removal of jack
138)Cold and viscous lo of an aux engine is most likely to cause___
A sudden stopping of engine (pawa)
B difficulty in starting
C rhythmic knocking sound frm inside of engine
D drop in rpm of engine
141)Which of the following anodes of iccp can b used for comparatively higher current densities?
Bhigh silicon iron
145)Which is biggest?
DTOTAL SUCTN HEAD
148)Which of the following valves are designed to have valve seats in pairs one facing the inlet side and other facing outlet side within the vv body?
A butterfly vv
B ball vv
C globe vv
D gate vv
152. The machinery which is usually tested first once the ship reaches a dry dock is
A.Engine room crane
B.Engine room lift
C.Gantry crane for engine room
D.All of the above
187) refer compr working continuously. Reason cud b apple
A insufficient condenser cooling
B air in the system
C leakage frm solenoid vv
D excessive refrigerant
29) The suction pressure gauge of the Engine room bilge pump is broken and you don???t have a spare. Chief Engineer has asked you to troubleshoot the problem with Bilge pump not taking suction from Fwd.(P) bilge well. You try taking suction from Fwd. (S) & Aft Bilge
well and find that pump is taking good suction. Thereafter you trysuction from Fwd. (P) bilge well for sometime after priming with Sea Water but there is no change in level. You inspect the suction filter of the pump and find that it is very difficult to remove the same, you had to apply too much of force to lift the filter cover while normally it comes out easily. What does it indicate?
A.It does not indicate anything, sometimes the filter covers are difficult to remove.
B.It indicates that the suction valve of the Fwd. Bilge Pump is leaking
C.It indicates that the suction filter of the Fwd. (P) bilge well is clogged completely
D.Pump suction filter might be clogged
191)The common term used for failure of metal and alloys in a corrosive environment , when subject to high stresses is known as : majority
C.Stress corrosion cracking
192)2 comprs shudnt b run in parallel because
A its not efficient
B it wil give overcapacity in the system
C there is possibility of loosing oil frm 1 compr to other
D a and b
195) Sludge pump suction pressure is going full vacuum when u start the pumptaking water of double bottom tank suction u hv checked the suction filter n found in clean condition. Taking suction fr fuel oil sludge tank does not happen. Causes of the problem.
A)Pump is not working efficiently n reqd. overhauling
B)F>O> sludge tank suction valve is leaking
C)W.O. tank D.B. tank suction pipeline has a blockage.
D)Can ???say what is the problem but definiterly the pump needs to b opened up for overhaul
Not preventing cold corrosion in M/E component
a.Running Evy aat high load
b.J/W cooling temp. high
c.High TNB cylinder oil
d.Cooling charge air in air cooler dew point
tilting box slide block pintle reaction ring
215)in ac room ppl complained of being too cool the problem might b A relative humidity high
B air velocity low
C heater failure to cut out at proper temp
D RH low
217)The process of depositing zinc on steel surfaces by diffusion coating is known as : A.Sherardising
B. Chromising C. Calorising
222)Double entry impellers have advantage over single entry impeller. Wat is it? A they balance out axial thrust
B it gives a higher pumping efficiency
C it is cheaper and easier to manufacture
D the need of installing line brg onto the pp shaft is eliminated.
1Impingement corrosion is a
C.Physical and chemical action
D.None of the above
2. It has been reported that Engine room bilge pump was unable to take suction from Fwd. (P) bilge well while it taking suction efficiently from Fwd.(S) & aft bilge wells. What could be the most probable cause?
(sure ans c)
A.There is leakage in the bilge suction pipeline somewhere between the bilge wells and bilge pump
B.The Fwd. (P) bilge well suction valve might be leaking
C.The Fwd. (P) bilge well suction filter cover gasket might be leaking
D.The pump needs to be overhauled
10) U R responsible for daily transfers of engine room bilges . U follow the sequences aft
taking suction fr f(p) n aft bilgewel n then u hv checked everything is normal. what is the cause.
A) 5th engineer made a mistake by 1st transferring the fwd (s) bilge wel,
normal sequence of operation for engine room machinaries should not b disturbed.
B)fwd (s) Bilge wel suction valve is leaking
C)Bilge pump suction filter cover gasket is leaking.
D)Fwd (s) Bilgewel suction filter cover gasket is leaking
22. In case of tankers, the speed of cargo pumps is reduced while stripping, why?
A.To avoid cavitation of the pump as the NPSHa may fall below NPSHr if speed is not reduced
B.To avoid cavitation of pump as the NPSHa may rise above NPSHr if speed is not reduced
C.To prevent the pump from over speeding if it loses suction
D.Decreasing the speed increases the discharge head of the pump which is required to pump out the remaining cargo
31. When one of the M/E.F.O. heater is not in use then
A)The F.O. inlet n outlet valve should b kept shut, but steam heating valves should b kept crack open so as to keep the heater warm.
B)F.O. inlet n outlet valve should b kept shut n heating valves also should b completely shut n should b drained of any remaining F.O.
c) F.O. inlet n outlet valve should b kept crack open so that the F.O. recirculation can take place.
d) F.O. inlet v/v kept shut n outlet valve should be left open so that hetar can be put into use as fast as possible in case required
38)aluminium being lower than zinc in galvanic series provides lesser protection to steel compared to the zinc coating . which one of the following is a true statement :
a.aluminium coating provides good corrosion protection compared that of zinc at elevated temperatures
b.zinc is always preferred over aluminium coating irrespective of the temperature of metal surface
c.aluminium is never used as coating material
d.aluminium reacts with steel , so cannot be used for coating steel
61)The automatic/manual recirculation valve provided on the S.W. overboard line is provided so that:
A.S.W. temperature can be regulated and coolers can maintain correct temperatures even with low S.W.temperatures.
B.S.W. temperature can be regulated and coolers can maintain correct temperatures even with high S.W.temperatures
C.S.W. can be
D.S.W. can be
97- An auxiliary engine
(a)Continue to run the engine and wait for some time
(b)Stop the engine for a while and make some checks
(c)Reduce the load of the engine
(d)Run it on steady load to make some checks
143)Your ship has ows and reciprocating bilge pp of capacity 2 m3/hr. it takes about 12 hrs to pp out whole bilge tk by that pp. the ship is going to drydock. And chief engr recommending company to install a centrifugal pp of capacity of 10 m3/hr. as a bilge pp so entire bilge tk can b pped out in 2.5 hrs.the company should:
A accept the proposal as a centrifugal pp has several advantages over a reciprocatin pp.
B there is no q of acceptin a c/f pp as bilge pp
C propose to fix a gear pp instead of a centrifugal pp
D pipelines and pps once designed cant b changed as they are class approved.
173.In a shell and type M/E L.O. cooler, the temperature of L.O. is controlled by an automatic temperature control valve. Out at sea with M/E running at sea load it is observed that the temperature control valve opening to the cooler is increasing day by until it becomes 100% open to the cooler. The L.O. outlet temperature _______________ after the above condition has reached
A.Starts decreasing immediately
B.Starts increasing immediately
C.Will be maintained at the set point of the temperature controller
D.Cannot be maintained at the set point and will increase slowly
204)26. A pump being used to deballast f for peak tank which is full, it it seen that suc pr is Positive n dis pressure is very low compared to rated discharge head, it indicates that
a.Pump is not operating satisfactorily n pump capacity is too low
b.Pump is not operating satisfactorily n Pumping capacity is higher than rated, Throttling of discharge valve is reqd.
c.Pumping capacity is not affected by suc n discharge pressure
d.Pump is operating normally
221)which of the follo is requirement for proper functnin of sacrificial anode sys? A good insulatn betnanodes and ships hull
B good electrical continuity betn anode and ships hull
C providing protection of anodes from being painted over during hull painting D presence of an insulating material betn anode and cathode
Which of the following can lead to sudden stopping of a diesel engine?
A. Air in fuel supply line
B. Water in fuel supply line
C. Obstruction in air filter
Water in D. the air
Correct method of greasing a centrifugal pump bearing is:
A.To pump the grease until you feel high back pressure on the Grease pump
B.To pump the greasefor
C.To pump the grease when the pump is stopped and drain any old grease at the same time by opening the drain plug, giving only
D.To pump the grease when the pump is running and drain any old grease at the same time by opening the drain plug,until all the old grease is removed and new grease starts coming out of the drain, repeating samefor each bearing. the drain plug should then be replaced
14 When pressure inside a system falls below that of the vapour pressure of the iquid
Cavities r formed, cavities travelling to high pressure region collapses releasing Considerable energy damage the metal surface which is known as
A)Cavitation B) Erosion
B)Impingment Corrosion D) Cavitation Erosion
37)A ball valve was found leaking in service. Upon inspection it was found that he PTFE seat had worn out and was renewed. The valve stopped leaking in closed condition. How do think a ball valve provides perfect sealing?
A.The seat fitted is slightly smaller than the outer dimensions of the ball, thus providing interference fit when closed
B.Either a floating seat is pressed onto trunnion supported ball by liquid pressure or floating ball is pressed onto the seat
C.Ball is not exactly spherical and is shaped such that during closure the surface coming into contact with seat is of slightly bigger diameter providing sealing
D.Seat is not exactly spherical, but slightly tapered so that during closure the ball sits tightly on the seat
43.which of the following is NOT a true statement?
a.butterfly valves are used modulating flow and can be throttled.
b.globe valve can be straight flow or angle flow type.(by samant this option)
c.swing check valve will provide lesser resistance than same bore dia globe ype check valve.
d.in a globe type valve mechanical seals are used for providing the sealing between spindle.
48)direction of rotation of centrifugal pump is reversed by changing the motor connections
a.pump will deliver the liquid in reverse direction
b.pump discharge and capacity will be affected
c.efficiency will decrease
d.casing get overheated
54)You have valves of same bore diameter but of different types.Which of the ollowing is
arranged in the decreasing order closing torque required for giving a perfect seal?
A.Globe valve, Ball valve, Butterfly valve(rubber seat)
B.Ball valve, Globe valve, Butterfly valve(rubber seat)
C.Butterfly valve(rubber seat), Globe valve, Ball valve
D.Globe valve, Butterfly valve(rubber seat), Ball Valve
116. Why centrifugal p/p not provided with safety valve while positive displacement p/p
a.c/f p/p shut down head is o
b.c/f p/p shut down head is infinity
c.c/f p/p is so designed that it can withstand high pressure
3.What will you do if the liquid start rising in the Surge Drum? (Direct cooling system)
a)Immediately reduce on the suction valve, and watch the Open more on the suction valve gauge.
b)Stop the compressor c)It will never happen.
d)Open more on the suction valve.
4.A drinking water circulating pump is
(a)In series with the F.W. hydrophore tank.
(b)In parallel with the F.W. hydrophore tank.
(c)Is used to transfer F.W. from deep tanks to hydrophore tanks.
(d)Is an unnecessary attachment to the hydrophoretank.
When securing a centrifugal distillate pump, which of the listed steps should be carried out FIRST?
1.Stop the pump.
2.Close the pressure gage valves. 3.Trip the
4.Close the sealing line valves to the pump
2)WHICH OF THE FOLL FACTOR WILL HAVE THE GREATEST EFFECT ON HEATING LOAD WITHIN ACONFINED SPACE
ANS INFILTERATION AND VENTILATION AIR
3)DIFFUSER IS PROVIDED AT THE END OF MECHANICAL ATOMISER IN BOILER ONBOARD
ANS TO MIX THE AIR AND FUEL PROPERLY
4)DUITY OF STANDBY PERSON AT THE ENTRY OF ENCLOSED SPACE COMPARTMENT IS
ANS TO ALERT OTHERS IN CASE OF EMERGENcy
5)PIPING CROSS SECTION RANGING FROM 3 TO 30IN DIA SIZED BY
ANS NOMINAL INSIDE DIA
6)PIPE THREADS ARE CUT WITH A TAPER TO
ANS TO PROVIDE A LEAKPROOF FIT
7)SCALE FORMATION IN FRESH WATER GENERATOR EVAPORATOR
ANS IMPAIRED HEAT TRANFER
INCREASED SHELL TEMP
ALL OF ABOVE
8)SHORT CYCLING OF FRIDGE COMP
ANS LEAKY SOLENOID V/V
Which of the following can lead to sudden stopping of a diesel engine?
A.Air in fuel supply line
B.Water in fuel supply line
C.Obstruction in air filter d. water in the air filter
Refer cooling tubes act as
. Air compressor cooler tube type a) Spring type b) Floating type c) Fixed tube d) U tube