MEP oral KUNDRA

1. Procedure for Overhaul of A/E.

a. Check whether all tools and spares are available or not.

b. If so, then start the Stand by generator.

c. Check all parameters are normal.

d. Now share the load with the help of synchroscope.

e. Again check all the parameters are within normal range.

f. Put full load on the Stand by generator.

g. Stop the generator on which work 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 system.

j. Let lube oil priming pump run for half hour after then stop it.

k. Drain the jacket water.

l. Remove the cylinder head cover.

m. Remove high pressure pipe.

n. Take out the injector using its tool.

o. Open the rocker arm bolts & remove it from its place.

p. Remove the Jacket 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 jack(As provided on your vessel).

s. Check the lifting gear (Crane & chain block, Eye bolt, etc.)

t. Lift the cylinder head & put it at a suitable place.

u. Open the crankcase door.

v. Bring the piston to TDC position & attach eye-bolt on it and Attach hook of chain block 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 bearing.

x. As load of piston is now on Lifting gear, so take it out & put it on the piston stand.

y. Remove the piston rings using ring extractor.

z. Remove the circlip from the gudgeon pin & take out the gudgeon pin, so connecting rod can be taken 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 check lifting gear.

a. Check the condition of wire rope & grease it.

b. Check the visual condition of chain.

c. Check the limit switches in the forward, aft, Port & starboard direction are working.

d. Check that emergency button is working.

e. Check the visual condition of the insulated cover is satisfactory.

f. Check overload trip is working satisfactorily.

g. Check the visual condition of chain block, no cracks should be there.

h. Check that safety latch is there on chain block.

1. What checks on piston and liner.

a. Piston:-

i. Check the piston for any cracks.

ii. Check the piston top profile.

iii. Check for any carbon deposits.

iv. Check the butt clearance, axial & radial clearance.

1. What to do if valve seat damaged?

1. Checks on crankcase inspection in Main Engine?

Safety Precautions:

1. Inform bridge and Chief Engineer.
2. If in port, take Immobilization certificate.
3. Get propeller clearance from the duty officer.
4. Shut off starting air valve.
5. Put “Men at Work” tag.
6. Stop lube oil pump.
7. Indicator cocks to open.
8. Turning gear should be engaged
9. Wear proper PPE, Shoes & helmet.
10. No naked lamp to be taken inside.
11. Open the crankcase door taking it as a shield.
12. Ventilate the crankcase door properly.
13. No items should be inside the pockets of boiler suit.

Inspection:

a. Check 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 black oil.

d. Check piston rod for any scoring & roughness.

e. Check piston palm bolts & locking.

f. Check the guide shoes and the area around it.

g. Check guide shoe end cover bolts.

h. Check X-head bearing general condition.

i. Check all bearing for white metal.

j. Check oil pan area of every unit for any sludge formations, bearing metals & foreign particles.

k. Check top & bottom of connecting rod bolts, nuts & locking device.

l. Check the axial movement of bottom end bearing.

m. Check slippage of web & journal by reference marks.

n. Check the teeth of transmission gear.

o. Check the tightness of chain drive.

p. Check c/case relief door spring tension, wire mesh & sealing ring.

q. Check & clear the O.M.D sampling pipes.

r. Start the lube oil pump & check flow .

s. Check c/case door sealing condition & close it c/case door.

t. Make sure no foreign matter or tools should be left inside the c/case.

1. Tappet clearances why plus how to check.

Tappet clearance is taken to ensure positive closing of the valve & for thermal expansion of the valve.

Taking all safety precautions.(See Ans. 1)

Make sure the piston is on TDC.

i. From the marking on the flywheel.

ii. From the fuel cam.

iii. Push rod should be free.

Make sure the engine has cooled down.

Loosen the lock nut of the rocker arm.

Now adjust the tappet clearance between the rocker arm & valve stem by tightening or loosing the nut below the lock nut.

If tappet clearance is less:

i. Valve will open early & close late

ii. Air induced through inlet valve may leak 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 pressure, 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 check 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 taken 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.

k. Emergency stop has activated.

l. Interlock is operated.

m. Cylinder air start valve defective or sticky.

n. Piston not in firing mode.

Engine not starting on fuel:

a. Less fuel in service tank.

b. Fuel filter is chocked.

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 rack stuck.

f. Fuel pump malfunctioning, jammed plunger.

g. Injector nozzle needle sticking or holes blocked.

h. Compression pressure is too low due to broken piston ring or exhaust valve not closing properly.

i. Fuel pump relief valve leaking.

j. Start air pressure insufficient to turn the engine fast enough.

1. What to check if Engine is not taking load.

1. What precautions to take to start A/E After overhaul.

a. Water tightness to be checked.

b. Air to be removed from jacket water outlet line.

c. Priming lube oil pump to run before starting the engine.

d. Check the lube oil level.

e. Check 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, then use small size gravity disc and follow this process until oil stops overflowing.

1. What to check 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 rack to zero position.

b. Operate any trip.

1. Charging gas in Dom Fridge?
2. Close the receiver outlet valve and collect the gas in the receiver.
3. Check the liquid level, if it is below L/3, Charging is reqd.
4. Check the weight of the refrigerant bottle & keep it upright.
5. Connect the charging line to the connecting point and keep it loose.
6. Open the bottle valve slightly and purge the line into the collecting cylinder and then tighten the connection.
7. Open the charging valve and fully open the bottle valve.
8. Check the liquid level in the sight glass and make sure no air bubble present in the system.
9. Close the charging valve and the bottle valve.
10. Open the receiver outlet valve & start the compressor.
11. 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 inside 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 sucking the oil.
5. Make sure the pipe is diped fully, because it has got chances of sucking air.
6. If air gets in, then purge it in a separate bottle after charging of oil gets completed.

1. What to check if Room temp (one room) not coming down?

-

1. What to check 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 working satisfactorily, unloader defective, valve leaky, rings damagd.

- Expansion valves choked/ malfunctioning.

- Evaporator blocked.

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. Less gas in system.
2. Drier Choked.
3. Expansion valve filter choked or Expansion valve Malfunction.
4. Evaporator Choked.
5. Compressor valves leaking.

Actions:-

a. Check L.P. Cut out setting, Cut out pressure OK.

b. Check flow of gas by seeing sight glass which should show full flow of refrigerant.

c. If no full flow- Either less gas or drier chocked, Clean the drier.

d. Check level in receiver, if low, then charge gas.

e. Expansion valve filter choked, then clean it.

f. Expansion valve malfunctioning- Change it.

g. Evaporator choked- 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 checks? What to do if pipe holed?
2. Check Sounding of bilge tank.
3. Check Bilge tank outlet v/v open or not.
4. Check P/p inlet v/v open or not.
5. Check p/p working properly.
6. 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 tank outlet v/v, then again put S.W

1. Boiler press coming up and gone above the safety valve lifting pressure. What 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 check and adjust.
2. Start the Stand by compressor.
3. Stop the compressor whose bumping clearance has to be taken.
4. Isolate the system.
5. Put “Men at Work” tag.
6. Loosen the cylinder head bolts and lift it.
7. Measure the diameter /size of the lead ball.
8. Bring piston to TDC and put lead ball on centre of it.
9. Now, put the cylinder head and tighten it to required torque.
10. Now, again loosen the cylinder head bolt and remove the ball.
11. Measure the size of the ball.
12. The difference between the initial size and final size is the bumping clearance.

It can be adjusted by either putting a thinner gasket or putting shim on top half of the bottom end bearing.

1. Removal of broken stud.

First drill the stud little bit & then use Thread extractor which has left hand thread.

1. Bridge informs lot of smoke from funnel what to do?
2. Reduce load on engine.
3. Check purifier operating alright/ reduce throughput to have better purification.
4. Drain water from settling & service tank.
5. Check scavenge air temperature & adjust if reqd. .
6. Soot blow the economizer.
7. Ensure, fuel oil end heater outlet temperature proper corresponding to attain viscosity at the point of injection.
8. Check, if any particular Exhaust temperature is higher than others, if so, then stop the engine, Change the injector with a spare overhauled injector.
9. Check all fuel pump timings are correct or not.
10. Dismantle and carry out overhaul of T/C.
11. 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 starting.
7. Other engineers will in between try to locate the hole or burst of pipe and 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.
13. Flooding in Engine Room what to do?

1. What checks to be made on Aux Engine when running?

Checks:

1. Check scavenge air temperature.
2. Check Exhaust gas temperature.
3. Check r.p.m
4. Check load on A/E.
5. Carry out peak pressure.
6. Check for any abnormal noise or vibration.
7. Check jacket water inlet & outlet temperature.
8. Check Lube oil temperature & pressure.

1. During running Main Engine stops. What checks?
2. Check whether Emergency stop operated by any personnel.
3. Check level of fuel oil in Service Tank.
4. Check whether purifier working properly.
5. Check whether water is there in Service tank due to improper purification.
6. Low lube oil pressure trip operated, Check L.O P/p developing correct pressure.
7. Control air trip operated, Check control air pressure.

1. Boiler blow back what to do and reasons?

Reasons:-

1. Insufficient pre-purging.
2. Blower not working.
3. Accumulation of oil.
4. Leaky solenoid valve.
5. Dripping of burner.

Action:-

1. Stop the firing.
2. Check the condition of burner, if it is dripping, then overhaul is required.
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?
2. Accept the alarm.
3. Find out the reason for extinguishing:-
4. if too low water level alarm came, then check pump is developing correct pressure or not , its is working properly.
5. If Tripped on high pressure, let the steam pressure come down.
6. Fuel oil low pressure alarm , then check functioning of fuel pump, oil in service tank.
7. Fuel oil low temp. alarm, then use the heater.
8. Flame failure trip, then clean flame eye, check the furnace & overhaul the burner.

1. Overhaul of fuel valve?

Safety Precautions:-

a. Check whether all tools and spares are available or not.

b. If so, then start the Stand by generator.

c. Check all parameters are normal.

d. Now share the load with the help of synchroscope.

e. Again check all the parameters are within normal range.

f. Put full load on the Stand by generator.

g. Stop the generator on which work 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 system.

j. Let lube oil priming pump run for half hour after then stop it.

k. Remove the lock nut of the high pressure pipe.

l. Now, remove the high pressure pipe.

m. Take out the fuel injector using it tool.

n. Put it on the testing kit.

o. Check the lifting pressure, atomization, pressure falling steadily, dripping of oil.

p. Now, take out the injector from the testing kit, put in a diesel oil & clean it.

q. Make sure the workshop table should be clean, no rags or jute to be there.

r. Put the injector on the vice and tighten it.

s. Loosen the lock nut of the injector.

t. Now loosen the compression nut to release the spring pressure, then take out the spring.

u. Open the cap nut and take out the needle and guide.

v. Put the parts on the cleaned table.

w. Check the condition of spring by dropping on the floor plate, it should jump and also check it by tightening in the vice and then releasing. The difference in the length,no cracks to be there.

x. Check visually needle, there shouldn’t be any scoring marks because it is made of Nitrite material.

y. Try to insert the needle inside the guide at angle of 45degree, the needle should on its own weight.

z. Check 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 needs to be changed.

iii. Now assemble the injector and do the lifting pressure setting on test kit by adjusting the compression nut.

iv. After this check the injector again for its lifting pressure, atomization, steady fall of pressure and dripping.

1. How pressure testing of Globe Valve is done?

a. Blank one side of valve and put water from the other side, check for any leakage.

1. Overhaul of a cylinder head & what all to check?

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 gas, 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 leak test carried out to know about the leakage/ crack in any part.

In it, first the part or unit is cleaned, paint is removed where the crack is suspected, then it marked on the unit. If water is coming, then colour will change, which shows the crack.

1. How alkalinity test is carried out?
2. Take 200 ml water sample in the stoppered bottle.
3. Add one P.Alkalinity tablet & shake or crush to disintegrate.
4. If P.Alkalinity is present the sample will turn blue.
5. Repeat the tablet addition, one at a time, until the blue colour turns to permanent yellow.
6. Count the number of tablets used and carry out the calculation:

P.Alkalinity, ppm CaCO3 = (Number of tablet x 20) -10

f. Record the result obtainied on the log sheet provided, against the date on which result was obtained.

1. Why water is kept 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 compressor.

1. What all clearances taken in centrifugal pump?
2. The wear ring & impeller.
3. The wear ring & the casing.
4. 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 mass 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 taking 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 take.

1. How to take out connecting road?

1. How to test cylinder head relief valve onboard?

1. During maneuvering Bursting disc of air compressor get damaged, what action to take?
2. Inform the bridge about the problem and to give lesser kicks.
3. Start the stand by compressor.
4. Isolate the compressor whose bursting disc is damaged.
5. Change the bursting disc, if available onboard.
6. If Not available, then let the S.W go into the E/room bilges, otherwise Fresh water cooled , then join a flexible hose and put into the expansion tank.

1. How will you test the crankcase 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. Ensure nobody is near the ship side blow down valve.
2. Not to be carried out in drydock or alongside.
3. Valve sequence to be followed.
4. Boiler shouldn’t be left unattended during blow down.
5. Monitor the end of blow down. Long blow down to be avoided.
6. Don’t blow down to the E/room bilges.

Procedure

1. Ship side valve 1 is opened followed by valve 2.
2. Valve 2 is NR which is fully opened to avoid cutting off seat.
3. Rate of blow down controlled by Valve 3.
4. For scum blow down valve 4 & 5 are used.

1. Action to be taken, if chloride content is excess?

Blow down of boiler to be carried out.

1. How to blow through boiler Gauge Glass?

Procedure:

1. Make 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 after 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. First tighten all the bolts by hand slightly without putting any pressure.
2. Now, tighten bolt 1 & 2 equally. Then 3 & 4.
3. Tighten bolt 5 & 6. then 7 & 8 equally.
4. Tighten bolt 9 & 10.
5. Now again tighten 7 & 8. Then 5 & 6.
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 purification plant

W - Larger capacity cooling water pump or separate piston cooling pump and coolers 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 leak

O - No special means required and leakage not a problem with less risk of hammering and bubble impingement.

W - Coolant drains tank required to collect water if engine has to be drained.

O - Increased capacity sump tank 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 quickly after engine stopped

O - Large volumes of oil required to keep oxidation down and extended cooling period required after engine stopped to prevent coking of oil

Bharatiyulam

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