1. Procedure for Overhaul of A/E. a. Chec
whether all tools and spares are available or not.
b. If so, then start the Stand by generator. c. Chec
all parameters are normal.
d. Now share the load with the help of synchroscope. e. Again chec
all the parameters are within normal range.
f. Put full load on the Stand by generator. g. Stop the generator on which wor
has to be carried out.
h. Put MEN AT WORK tag. i. Shut the air starting valve, fuel oil inlet & outlet valves and isolate the s ystem. j. Let lube oil priming pump run for half hour after then stop it. . Drain the jac et water. l. Remove the cylinder head cover. m. Remove high pressure pipe. n. Ta e out the injector using its tool. o. Open the roc er arm bolts & remove it from its place. p. Remove the Jac et water outlet pipe. q. Disconnect the scavenge & exhaust manifold from the cylinder head. r. Open the cylinder head bolts using the Torque spanner or hydraulic jac (As pr ovided on your vessel). s. Chec
the lifting gear (Crane & chain bloc , Eye bolt, etc.)
t. Lift the cylinder head & put it at a suitable place. u. Open the cran case door. v. Bring the piston to TDC position & attach eye-bolt on it and Attach hoo of c hain bloc to it.(Before bringing Piston to TDC, the top part of liner needs to be cleaned) w. Bring the piston to BDC and open the bottom-end bolts & remove bottom end bea ring. x. As load of piston is now on Lifting gear, so ta e it out & put it on the pist on stand. y. Remove the piston rings using ring extractor. z. Remove the circlip from the gudgeon pin & ta e out the gudgeon pin, so connec ting rod can be ta en out.
1. How do you decide if piston rings should be changed or not? a. Butt clearance increased then its normal range. b. Axial clearance increased. c. Visual condition of piston ring. 1. How you chec
lifting gear.
a. Chec
the condition of wire rope & grease it.
b. Chec
the visual condition of chain.
c. Chec the limit switches in the forward, aft, Port & starboard direction are wor ing. d. Chec
that emergency button is wor ing.
e. Chec
the visual condition of the insulated cover is satisfactory.
f. Chec
overload trip is wor ing satisfactorily.
g. Chec
the visual condition of chain bloc , no crac s should be there.
h. Chec
that safety latch is there on chain bloc .
1. What chec s on piston and liner. a. Piston:i. Chec ii. Chec iii. Chec iv. Chec
the piston for any crac s. the piston top profile. for any carbon deposits. the butt clearance, axial & radial clearance.
1. What to do if valve seat damaged? 1. Chec s on cran case inspection in Main Engine? Safety Precautions: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
Inform bridge and Chief Engineer. If in port, ta e Immobilization certificate. Get propeller clearance from the duty officer. Shut off starting air valve. Put Men at Wor tag. Stop lube oil pump. Indicator coc s to open. Turning gear should be engaged Wear proper PPE, Shoes & helmet. No na ed lamp to be ta en inside. Open the cran case door ta ing it as a shield. Ventilate the cran case door properly. No items should be inside the poc ets of boiler suit.
Inspection: a. Chec
the condition of lube oil, for any smell, discoloration, degradation.
b. No paint parts to be there in the sump. c. Turn the engine to BDC and under stuffing box area for any blac d. Chec
piston rod for any scoring & roughness.
e. Chec
piston palm bolts & loc ing.
f. Chec
the guide shoes and the area around it.
g. Chec
guide shoe end cover bolts.
h. Chec
X-head bearing general condition.
i. Chec
all bearing for white metal.
oil.
j. Chec oil pan area of every unit for any sludge formations, bearing metals & foreign particles. . Chec
top & bottom of connecting rod bolts, nuts & loc ing device.
l. Chec
the axial movement of bottom end bearing.
m. Chec
slippage of web & journal by reference mar s.
n. Chec
the teeth of transmission gear.
o. Chec
the tightness of chain drive.
p. Chec
c/case relief door spring tension, wire mesh & sealing ring.
q. Chec
& clear the O.M.D sampling pipes.
r. Start the lube oil pump & chec s. Chec
flow .
c/case door sealing condition & close it c/case door.
t. Ma e sure no foreign matter or tools should be left inside the c/case. 1. Tappet clearances why plus how to chec . Tappet clearance is ta en to ensure positive closing of the valve & for thermal expansion of the valve. Ta ing all safety precautions.(See Ans. 1) Ma e sure the piston is on TDC. i. From the mar ing on the flywheel. ii. From the fuel cam. iii. Push rod should be free. Ma e sure the engine has cooled down.
Loosen the loc
nut of the roc er arm.
Now adjust the tappet clearance between the roc er arm & valve stem by tightenin g or loosing the nut below the loc nut. If tappet clearance is less: i. Valve will open early & close late ii. Air induced through inlet valve may lea
out. So, less air for combustion.
iii. Power will be reduced. iv. Fuel consumption will increase, engine may become unbalanced, exhaust temp. will be very high. v. In worst condition, valve may remain open, resulting in loss of compression p ressure, burning of exhaust valve, T/C fouling will increase. If tappet clearance is more: i. Valve will open late & close early. ii. Lesser heat energy to T/C, so reduction in scavenge air & hence power. iii. No proper removal of gases. iv. Hammering of valve stem-may cause damage to valve stem. 1. What to chec
if Engine is not starting on air and fuel
Engine not starting on Air:a. Low air bottle pressure or air line valve may be shut. b. Air bottle isolating valve or automatic valve or distributor not functioning. c. Control air valves faulty or less control air pressure. d. Start air automatic valve jammed. e. Turning gear engaged. f. Reversing has not ta en place completely. g. Control valve for fuel or start is not in it s end position. h. Bursting diaphragm on start air line damaged. i. Fuel lever on maneuvering stand not on remote mode. j. Auxiliary blower not running or not on auto mode. . Emergency stop has activated. l. Interloc
is operated.
m. Cylinder air start valve defective or stic y. n. Piston not in firing mode.
Engine not starting on fuel: a. Less fuel in service tan . b. Fuel filter is choc ed. c. Fuel supply pumps not delivering required pressure. Or fuel pump tripped. d. Fuel level on local maneuvering stand, is not on remote stand. e. Fuel rac
stuc .
f. Fuel pump malfunctioning, jammed plunger. g. Injector nozzle needle stic ing or holes bloc ed. h. Compression pressure is too low due to bro en piston ring or exhaust valve no t closing properly. i. Fuel pump relief valve lea ing. j. Start air pressure insufficient to turn the engine fast enough. 1. What to chec
if Engine is not ta ing load.
1. What precautions to ta e to start A/E After overhaul. a. Water tightness to be chec ed. b. Air to be removed from jac et water outlet line. c. Priming lube oil pump to run before starting the engine. d. Chec
the lube oil level.
e. Chec
the flow of lube oil.
f. Blow through the engine before starting. 1. How to change purifier to clarifier. Remove the gravity disc. 1. How to select damn ring for purifier. From the monogram provided with manual, which is drawn with respect to viscosity of oil & which size damn ring to be used. If monogram not there, then a. Chief Engineers experience will come into use. b. Hit & trial method to be used. i. First use the largest gravity disc and whether oil is overflowing, if so, the n use small size gravity disc and follow this process until oil stops overflowin g. 1. What to chec
if purifier over flowing.
a. Size of gravity disc. b. High throughput. c. Temperature of the oil. 1. How to stop Aux Engine if not stopping by stop handle. a. Pull the fuel rac
to zero position.
b. Operate any trip. 1. Charging gas in Dom Fridge? 1. Close the receiver outlet valve and collect the gas in the receiver. 2. Chec the liquid level, if it is below L/3, Charging is reqd. 3. Chec the weight of the refrigerant bottle & eep it upright. 4. Connect the charging line to the connecting point and eep it loose. 5. Open the bottle valve slightly and purge the line into the collecting cyli nder and then tighten the connection. 6. Open the charging valve and fully open the bottle valve. 7. Chec the liquid level in the sight glass and ma e sure no air bubble pres ent in the system. 8. Close the charging valve and the bottle valve. 9. Open the receiver outlet valve & start the compressor. 10. Carry out let detector test. 1. Charging oil in Domestic fridge. Method 1. 1. Mostly ships have hand p/p provided which develop more pressure than the i nside pressure. Method 2. 1. Reduce the L.P Cut out setting. 2. Dip the pipe inside the c/case of compressor. 3. Run compressor, vaccum will develop. 4. So, compressor will start suc ing the oil. 5. Ma e sure the pipe is diped fully, because it has got chances of suc ing a ir. 6. If air gets in, then purge it in a separate bottle after charging of oil g ets completed. 1. What to chec
if Room temp (one room) not coming down?
1. What to chec
if all room temp not coming down?
-
- Room doors not shut properly. - Room insulation is bad. - Air in system. - Room fans not running.
- Evaporators frosted. - Compressor not wor ing satisfactorily, unloader defective, valve lea y, rings damagd. - Expansion valves cho ed/ malfunctioning. - Evaporator bloc ed. 1. What to do if dom. fridge is short cycling/ - L.P Cut out is defective. - L.P Cut out setting not correct, too low difficult for Cut In. - Lesser gas flow 1. 2. 3. 4. 5.
Less gas in system. Drier Cho ed. Expansion valve filter cho ed or Expansion valve Malfunction. Evaporator Cho ed. Compressor valves lea ing.
Actions:a. Chec
L.P. Cut out setting, Cut out pressure OK.
b. Chec erant.
flow of gas by seeing sight glass which should show full flow of refrig
c. If no full flow- Either less gas or drier choc ed, Clean the drier. d. Chec
level in receiver, if low, then charge gas.
e. Expansion valve filter cho ed, then clean it. f. Expansion valve malfunctioning- Change it. g. Evaporator cho ed- Blow-thru evaporator with nitrogen. 1. Overhaul of centrifugal pump. 1. Changing pipe join below floor plate without removing pipe. 1. Can not pump out bilges. What chec s? What to do if pipe holed? 1. 2. 3. 4. 5.
Chec Sounding of bilge tan . Chec Bilge tan outlet v/v open or not. Chec P/p inlet v/v open or not. Chec p/p wor ing properly. If vaccum developing that means hole in pipeline.
If pipe is holed:1. Carry out Vaccum test by closing inlet valve & opening outlet /v. 2. If hole is between the inlet v/v and p/p, vaccum will develop, now remove top of v/v and put water. 3. If hole is in between Inlet v/v and bilge tan outlet v/v, then again put S.W
1. Boiler press coming up and gone above the safety valve lifting pressure. W hat to do? Use the easing gear to release the excess pressure. 1. Bridge informs steering not responding. What to do? 1. Air comp bumping clearance how to chec
and adjust.
1. Start the Stand by compressor. 2. Stop the compressor whose bumping clearance has to be ta en. 3. Isolate the system. 4. Put Men at Wor tag. 5. Loosen the cylinder head bolts and lift it. 6. Measure the diameter /size of the lead ball. 7. Bring piston to TDC and put lead ball on centre of it. 8. Now, put the cylinder head and tighten it to required torque. 9. Now, again loosen the cylinder head bolt and remove the ball. 10. Measure the size of the ball. 11. The difference between the initial size and final size is the bumping clea rance. It can be adjusted by either putting a thinner gas et or putting shim on top hal f of the bottom end bearing. 1. Removal of bro en stud. First drill the stud little bit & then use Thread extractor which has left hand thread. 1. Bridge informs lot of smo e from funnel what to do? 1. Reduce load on engine. 2. Chec purifier operating alright/ reduce throughput to have better purific ation. 3. Drain water from settling & service tan . 4. Chec scavenge air temperature & adjust if reqd. . 5. Soot blow the economizer. 6. Ensure, fuel oil end heater outlet temperature proper corresponding to att ain viscosity at the point of injection. 7. Chec , if any particular Exhaust temperature is higher than others, if so, then stop the engine, Change the injector with a spare overhauled injector. 8. Chec all fuel pump timings are correct or not. 9. Dismantle and carry out overhaul of T/C. 10. Send fuel oil for Laboratory analysis. Reasons: 1. Improper combustion. 2. Burning of carbon particles collected at EGE. 3. Overloading of engine. 4. Inform bridge & Chief engineer. 5. Raise engineers call/emergency alarm. 6. Before starting bilge pump note down the position of vessel & time of star ting. 7. Other engineers will in between try to locate the hole or burst of pipe an d repair. 8. If ingress of water very high, start another pump. 9. Reduce the engine r.p.m. 10. Change over main s.w suction to emergency bilge suction.
11. If level is still coming up try to protect the motor from short-circuiting , if required start emergency bilge suction valve. 12. If situation is not coming in control, prepare lifeboat for lowering. 1. Flooding in Engine Room what to do? 1. What chec s to be made on Aux Engine when running? Chec s: 1. 2. 3. 4. 5. 6. 7. 8.
Chec Chec Chec Chec Carry Chec Chec Chec
scavenge air temperature. Exhaust gas temperature. r.p.m load on A/E. out pea pressure. for any abnormal noise or vibration. jac et water inlet & outlet temperature. Lube oil temperature & pressure.
1. During running Main Engine stops. What chec s? 1. 2. 3. 4. 5. sure. 6.
Chec whether Emergency stop operated by any personnel. Chec level of fuel oil in Service Tan . Chec whether purifier wor ing properly. Chec whether water is there in Service tan due to improper purification. Low lube oil pressure trip operated, Chec L.O P/p developing correct pres Control air trip operated, Chec
1. Boiler blow bac
control air pressure.
what to do and reasons?
Reasons:1. 2. 3. 4. 5.
Insufficient pre-purging. Blower not wor ing. Accumulation of oil. Lea y solenoid valve. Dripping of burner.
Action:1. Stop the firing. 2. Chec the condition of burner, if it is dripping, then overhaul is require d. 3. Do the inspection of the furnace. 4. Carry out sufficient pre-purging. 5. Start the boiler on Auto mode. 1. Boiler extinguishes what to do? 1. Accept the alarm. 2. Find out the reason for extinguishing:3. if too low water level alarm came, then chec pump is developing correct p ressure or not , its is wor ing properly. 4. If Tripped on high pressure, let the steam pressure come down. 5. Fuel oil low pressure alarm , then chec functioning of fuel pump, oil in service tan . 6. Fuel oil low temp. alarm, then use the heater. 7. Flame failure trip, then clean flame eye, chec the furnace & overhaul the burner.
1. Overhaul of fuel valve? Safety Precautions:a. Chec
whether all tools and spares are available or not.
b. If so, then start the Stand by generator. c. Chec
all parameters are normal.
d. Now share the load with the help of synchroscope. e. Again chec
all the parameters are within normal range.
f. Put full load on the Stand by generator. g. Stop the generator on which wor
has to be carried out.
h. Put MEN AT WORK tag. i. Shut the air starting valve, fuel oil inlet & outlet valves and isolate the s ystem. j. Let lube oil priming pump run for half hour after then stop it. . Remove the loc
nut of the high pressure pipe.
l. Now, remove the high pressure pipe. m. Ta e out the fuel injector using it tool. n. Put it on the testing o. Chec of oil.
it.
the lifting pressure, atomization, pressure falling steadily, dripping
p. Now, ta e out the injector from the testing it.
it, put in a diesel oil & clean
q. Ma e sure the wor shop table should be clean, no rags or jute to be there. r. Put the injector on the vice and tighten it. s. Loosen the loc
nut of the injector.
t. Now loosen the compression nut to release the spring pressure, then ta e out the spring. u. Open the cap nut and ta e out the needle and guide. v. Put the parts on the cleaned table. w. Chec the condition of spring by dropping on the floor plate, it should jump and also chec it by tightening in the vice and then releasing. The difference i n the length,no crac s to be there. x. Chec visually needle, there shouldn t be any scoring mar s because it is made of Nitrite material.
y. Try to insert the needle inside the guide at angle of 45degree, the needle sh ould on its own weight. z. Chec
the size of injecting holes by using Go or No go gauge.
i. If go gauge is going then hole size is OK. ii. If no go gauge going, then it means the size has increased, then nozzle need s to be changed. iii. Now assemble the injector and do the lifting pressure setting on test y adjusting the compression nut.
it b
iv. After this chec the injector again for its lifting pressure, atomization, s teady fall of pressure and dripping. 1. How pressure testing of Globe Valve is done? a. Blan age.
one side of valve and put water from the other side, chec
for any lea
1. Overhaul of a cylinder head & what all to chec ? 1. Overhaul of Inlet & exhaust valve of aux.enine? 1. Function of Roto-Cap in valves & how it is overhauled? a. It helps to rotate the valve during operation with the help of the exhaust ga s, so as less wear occurs and stress doesn t comes only at one point. 1. What is dye-pentration test, why is it done & how is it done? Dye-Penetration test is a lea in any part.
test carried out to
now about the lea age/ crac
In it, first the part or unit is cleaned, paint is removed where the crac is su spected, then it mar ed on the unit. If water is coming, then colour will change , which shows the crac . 1. How al alinity test is carried out? 1. Ta e 200 ml water sample in the stoppered bottle. 2. Add one P.Al alinity tablet & sha e or crush to disintegrate. 3. If P.Al alinity is present the sample will turn blue. 4. Repeat the tablet addition, one at a time, until the blue colour turns to permanent yellow. 5. Count the number of tablets used and carry out the calculation: P.Al alinity, ppm CaCO3 = (Number of tablet x 20) -10 f. Record the result obtainied on the log sheet provided, against the date on wh ich result was obtained. 1. Why water is
ept heated in hot-well?
1. To prevent oxidation 2. To avoid thermal stress on boiler. 1. Position of Unloader in AC & Ref. compressor ?
Unloader in AC & Ref. compressor is located near the suction valve of the compre ssor. 1. What all clearances ta en in centrifugal pump? 1. The wear ring & impeller. 2. The wear ring & the casing. 3. Shaft and the bush. 1. Why centrifugal pump is not self priming? Because of the churning effect it is not be able to remove air positively as mas s of air is relatively zero. 1. What is the position of bearing in centrifugal pump? Near the impeller. 1. What is the position of piston when ta ing bearing clearances - Main Bearing Clearance --B.D.C - Bottom End bearing clearance B.D.C - Cross-head bearing clearance. B.D.C 1. How to overhaul gear pump and centrifugal pump? And clearance to ta e. 1. How to ta e out connecting road? 1. How to test cylinder head relief valve onboard? 1. During maneuvering Bursting disc of air compressor get damaged, what actio n to ta e? 1. Inform the bridge about the problem and to give lesser ic s. 2. Start the stand by compressor. 3. Isolate the compressor whose bursting disc is damaged. 4. Change the bursting disc, if available onboard. 5. If Not available, then let the S.W go into the E/room bilges, otherwise Fr esh water cooled , then join a flexible hose and put into the expansion tan . 1. How will you test the cran case relief door? The testing of the C/case relief door is done at shore. 1. Reasons of Purifier overflow? 2. Procedure for doing boiler blow down? Precautions 1. 2. 3. 4. 5. 6.
Ensure nobody is near the ship side blow down valve. Not to be carried out in drydoc or alongside. Valve sequence to be followed. Boiler shouldn t be left unattended during blow down. Monitor the end of blow down. Long blow down to be avoided. Dont blow down to the E/room bilges.
Procedure
1. 2. 3. 4.
Ship side valve 1 is opened followed by valve 2. Valve 2 is NR which is fully opened to avoid cutting off seat. Rate of blow down controlled by Valve 3. For scum blow down valve 4 & 5 are used.
1. Action to be ta en, if chloride content is excess? Blow down of boiler to be carried out. 1. How to blow through boiler Gauge Glass? Procedure: 1. Ma e sure drain line is clear 2. Close the steam outlet valve. 3. Close the water outlet valve. 4. Open the drain valve. 5. Open the water out valve & let water flow thru it and close the valve afte r blowing down with water. 6. Open the steam out valve and blow thru with steam. 7. Close steam valve. 8. Close the drain valve. 9. Now, open the water side valve. 10. Let water fill up 3/4th gauge glass. 11. Open the steam valve slowly. 1. How to tighten boiler gauge glass after overhauling? Procedure of tightening: 1. 2. 3. 4. 5. 6.
First tighten all the bolts by hand slightly without putting any pressure. Now, tighten bolt 1 & 2 equally. Then 3 & 4. Tighten bolt 5 & 6. then 7 & 8 equally. Tighten bolt 9 & 10. Now again tighten 7 & 8. Then 5 & 6. Tighten bolt 3 & 4. then 1 & 2.
Or you can say we first tighten outward bolts of both side & then inward side. Then we move in opposite steps. i.e. tight inward bolts & then outward bolts. Differences betwn Watercooled and Oilcooled piston W - High specific heat capacity therefore removes more heat per unit volume O - Low specific heat capacity W - Requires chemical conditioning treatment to prevent scaling O - Does not require chemical treatment but requires increased separate and puri fication plant W - Larger capacity cooling water pump or separate piston cooling pump and coole rs although less so than with oil O - Larger capacity Lube oil pump, sump quantity and coolers W - Special piping required to get coolant to and from piston without lea O - No special means required and lea age not a problem with less ris
of hammer
ing and bubble impingement. W - Coolant drains tan
required to collect water if engine has to be drained.
O - Increased capacity sump tan
required
W - Pistons often of more complicated design O - Thermal stresses in piston generally less in oil cooled pistons W - Cooling pumps may be stopped more quic ly after engine stopped O - Large volumes of oil required to eep oxidation down and extended cooling pe riod required after engine stopped to prevent co ing of oil
