MARINE ENGINEERING :MEO Exams

1. remove plug from inlet pipe and remove oil . 2.remove sealing water pipe, inlet and outlet pipes. 3.remove flow rate regulating orifice plate from the inlet side. 4. Remove cover-nut, nut tightening inlet pipe and socket set screw( holding inlet pipe from rotation). 5. slightly hammer on top of the inlet pipe to detach tightly held tapered portion. 6. remove sludge cover nuts(top cover) and remove sludge cover by mounting a jack for removing it. 7. Using disc nut handle remove disc nut and remove heavy liquid chamber,impeller and gravity disc n sealing ring) 8. Mount the light liquid chamber handle and remove light liquid chamber and impeller with inlet pipe. 9. Remove the capnut (tightening bowl on to the vertical shaft using cap-nut removing spanner(set the spanner on the cap nut and thread the threaded rod on to the top of cap-nut and remove). 10. Mount the jack on the threaded portion of the distributor , turn down the jack until the bowl is slightly raised.

Brake linings are pushed against the outer surface of a friction pulley by springs, used for stopping in emergency and prevent purifier running through critical rpm range.

Horizontal shaft is supported by two bearings attached to the casing and gear pump is attached with a safety joint.

Vertical shaft is rotated by a spiral gear in horizontal shaft meshing with a pinion in the vertical shaft. Supported by 6 radial springs, upper flat spring and a bottom spring.

1. Bowl nut( circular bolt on bowl(look for tally marks) 2. Disc nut(Holding heavy liquid chamber on to the bowl)

1. Dirty cooling surfaces. ( Clean cooling surfaces of cylinder intercooler and discharge tube) 2. Poor ventilation.  (Improve ventilation or relocate compressor.)

The pressure relief valve acts as a backup safety device to the pressure switch. It is designed to automatically open when the pressure in the receiver reaches dangerous levels. The pressure relief valve is tested by running the air compressor with the pressure switch fully open. When the pressure switch is fully open it cannot shut down the compressor.

lube oil failure, head cooling failure, broken piston rings or valves,

1. Relief valve: Fitted after every stage to release excess pressure developed inside it. The setting of the lifting pressure increases after every ascending stage. 2 .copper Bursting disc : A bursting disc is a copper disc provided at the air side of the compressor. It is a safety disc, which bursts when the pressure exceeds over the per-determined value. 3.Fusible plug: Generally located on the discharge side of the compressor, it fuses if the air temperature is higher than the operational temperature. The fusible plug is made up of material, which melts at high temperature. 4 .Lube Oil low-pressure alarm and trip: If the lube oil pressure goes lower than the normal, the alarm is sounded followed by a cut out trip signal to avoid damage to bearings and crank shaft

Check for direction of rotation, clean suction filter, check the pressure switch. Check lo pump, check for excessive foaming of lube oil.

Flat plate design - Has a bigger surface area for full escape and low valve lift results in low inertia ie. a faster opening and closing of valve. caged structure prevents shock loading of the valve and plate springs instead of coils prevent spring failure and seizure due o fatigue.

floating  type gudgeon pin in an air compressor In air compressor the crankshaft, is driving the piston in all strokes

volume of discharged air as free air/swept volume of lower pressure piston

bumping clearance, sluggish opening of valves, leakage past piston rings,

Overhauling of Air compressors Remove the cylinder head after disconnecting all connections, Remove all the air valves for both stage suction and delivery. Check the condition of valve by properly cleaning it and then using a steel check the valve plate by pressing it. Leakage past the valve also  can be checked, if not satisfied overhaul or replace. Now remove both cooler covers and remove coolers, clean both jackets and coolers. Inside of the cylinder to be checked for improper wear or scoring and also the working of lubricator to be checked. The piston can be removed by removing the rod cap from the con rod

Regularly drain it of water & oil. Check for corrosion internally and externally,internal coating (copal),welding seam( dry penetration), Check face of manhole for pitting marks, Overhaul valves, replace gaskets & check seats for wire drawing effects, Safety valves to be inspected as per class requirement. (if excessive corrosion in air bottle derating must be done, its is decided by class surveyor) Air bottle viewed through Manhole

With increase in valve lift, volumetric efficiency drops. Improper valve lifts can be checked by checking parameters of aircompressor.

1.Relief valve 2. Low pressure alarm 3. Fusible plug

1.Pump down the ref gas in condenser and close the inlet and outlet of the condenser 2.There are cock provided at the inlet and outlet of the evaporator coil

Compressor capacity is measured in cubic meter per hour FAD(free air delivery) it is the amount of air a compressor can deliver at 15 degree Celsius and 1.013bar

When   the   compressor   is   not   in   operation,   the unloader  mechanism  is  in  the  unloaded  position. The mechanism is operated by oil pressure  from  the  capacity  control  valve.  The  oil pressure pushes the Unloader spring against the unloader piston.This action moves the unloader rod to the left, thereby  rotating  the  cam  rings. 

At the end of stroke the clearance space will be full of high pressure air which has to be expanded until pressure within the cylinder is low enough for the suction valve to open.(ie large part of suction stroke is made ineffective)

In refrigerant compressors dual pressure gauges which shows saturation temperature for particular pressure is used.

Bumping clearance= clearance volume. If more- volumetric efficiency drops, if less- piston hits the head.  Cause of change in bumping clearance during service- 1, wear in crank pin bearing( symptoms slow decrease in oil pressure and knocking sounds in later stages). 2, change in size of head gaskets. 3. wear in main bearing. effects of large clearances-FAD decreases, air outlet temperature increases. checking bumping clearances- using a lead wire pressed between head and piston inserted through the valve opening and connecting rod jacked up using a crowbar correcting clearances: cylinder head gaskets to be changed size, inserting shims between big end of con-rod

In tandem type compressor, the higher pressure piston (bottom) is lubricated by splash from the crankcase or forced lubricated using lubricators and pump. The top stage is invariably lubricated by lubrication pump drawing suction from the crankcase. Running gear is force lubricated by a pressure pump drawing oil from the crankcase discharges it through through the main bearing to  the crankshaft passage into the bottom end bearings and traveling to gudgeon pin. the pump is operated by an eccentric drive attached to the shaft or roller chain. 

1. if the level of oil in the crankcase is high consumption increases 2 Restricted air intake. ( Clean or replace air filter.) 3 Oil leaks.  (Tighten bolts or replace gasket.) 4 Worn piston rings.  (Replace rings.) 5 Wrong oil viscosity.  (Drain oil, refill with oil of proper viscosity.) 6 Compressor tilted too much.  (Level compressor. Vibration pads may help with this) 7. Scored cylinder.  (Replace cylinder)

*oxidation resistance from the heated air/oil compression • Resist acid buildup due to oxidation from extended oil drain intervals, moisture and heat • Exhibit good demulsibility to separate the water from the oil • Prevent against internal rust formation • Resist foaming • Control air entrainment • Reduce wear • Maintain viscosity parameters • Extend oil drain intervals • Provide low temperature fluidity protection

No of stages used is governed by the required final pressure. When air is compressed in stages its easier to control the temperature of air. The cooling in intercoolers lowers the work done on compressing. The work saved is evident in the PV diagram, It also has the advantages of less difficulty experienced in lubrication and coking of valves due to the higher air temperature in the single stage compressors. Reason for reduction in work done while compressing in stages. adiabatic compression if air is compressed and heat is not removed(PVɣ= constant), isothermal compression if heat is completely removed(PV=constant).  for compression with inter-cooling, the compression approaches a isothermal compression which is called a polytropic process where (PVn= constant)  since value of n < ɣ the slope of pV diagram is reduced.  {value of ɣ is the ratio of specific heat of air at constant pressure to constant volume} {value of n depends inter cooling is between 1.35 to1.25}

a) Lube oil Low-pressure alarm & trip. (b) Lube oil High temperature alarm. (c) Over speed trip (d) High back pressure alarm & trips. (e) High discharge pressure alarm & trip. (f) Steam inlet low-pressure trip.

1. Switch on the power supply from local control panel situated in COPT platform.2. Check the oil level in the oil tank and the governor. 3. Start the LO priming pump, confirm the LO pressure reaches above 0.3 bar. 4. Start COPT condenser cooling water pump and COPT condensate pump.  5. open fully the drain valves listed below (a) Steam inlet line drain (b) Governor valve drain (c) Turbine casing drain  6. Confirm all exhaust valve are open. 7. Turn the turbine several revolution by the

Alarms in IG System : - a. Scrubber High Level b. Scrubber low level c. Deck seal High level d. Deck seal low level e. High O2 Content f. High blower casing temp. g. Low lube oil pressure alarm. Trips in IG System: - a. High Casing Temp. Trip b. Low lube oil pressure trip. c. Low/ no flow scrubber water d. Low / no flow deck seal water. e. High boiler pressure trip. f. Low boiler pressure trip.

Grey or colourless- good, white- steam, blue- lub oil, yellow sulphur content high. Black smoke- lack of air or faulty combustion equipment.

Flame screen :will not let the fire to come in from outside. Flame Arr-ester will not let the fire to come out from inside.

Used to detect cracks in components on board ship. Penetrant is same penetrating oil used to loose a rusted nut & bolt except it contains a dye which will find its way in to the smallest of cracks, even those invisible to the naked eye. Some of them are fluorescent dye, which is then used in conjunction with an ultraviolet light, which makes the cracks glow green when ordinary lighting is reduced.Some of them are developer which makes the dye stand out as a red line. This type usually comes in three aerosols. • First is cleaner, which is sprayed on it. • Then the component is allowed to dry. • Then the penetrating dye is sprayed on & after 5 minutes the excess coating on surface is wiped off. • The developer is sprayed on which will highlight any crack present.

1. Expansion valve or solenoid valve stuck 2. room insulation failure or door kept open 3. defrosting in evaporator.

Effectiveness of raw sewage treatment is measured in bod, 1 litre of sample is kept in well oxygenated environment for 5 days in 20 degree Celsius.amount of oxygen consumed in five days is measured and expressed as bod 5.

With lube oil charging pump, connect the discharge line compressor oil charging connection and purge oil before tightening.Fill the oil with even strokes of pump, checking for air ingree filling upto the mark.

It is a type of coupling used for absorbing vibration, fitted on pipes like scavenge drain pipe , in tank’s steam heating coils, where lot of vibrations can arise due to water hammering effects.

1. Pump down the ref gas in condenser and close the inlet and outlet of the condenser 2. There are cock provided at the inlet and outlet of the evaporator coil 3.Open inlet and outlet of evaporator coil and blow through by nitrogen

Permit thermal expansion of parts by allowing it to expand in different direction. Absorb vibrations

For no load starting of compressor starting in large units is done by keeping suction valve open or by opening a bypass between suc an discharge side

Mud boxes are fitted into the machinery space bilge suction piping. The mud box is a coarse strainer with a straight tailpipe down to the bilge. To enable the internal perforated plate to be cleaned when necessary, the lid of the mud box is easily removed without disconnecting any pipe work

TYPE 1. the condensor is bypassed and gas is recirculated(by pass method). TYPE 2. here cycle is reversed using four way valves and check valves.

filter is a fine mesh inserted in pipelines usually in the discharge side and return line usual size is mentioned in microns which is the smallest particle it can filter. Strainer is a coarse mesh inserted in the suction line usually used to protect the pumps from heavy debries.size is mentioned as holes in mesh.

Used in installations with a large drop in pressure across the evaporators. In TEV the pressure acting on top of the bellow corresponded to the saturation pressure of refrigerant leaving the evaporator.

There is fluctuation of gauges if air is present as air is compressible while the liquid is not,

The High and Low Suctions are a Safety Feature to prevent invertent Shut Down of Main Engines, Generators and Boilers due to Water Contamination of the Fuel.  Normally the Low Suction is kept in use. 

Principle of viscotherm is that in a laminar flow the drop of pressure fluid is directly proportional to the drop in pressure. A sample of fuel is pumped through a capillary tube at a constant rate . Tapping points are provided so that the pressure difference can be measured using a differential pressure gauge.the gauge is calibrated directly in terms of the viscosity. a differential pressure transmitter is provides a signal and controls the fuel heating.

detection of air : high condensor pressure, small bubbles in sight glass, compressor discharge pressure high or running hot,More superheat, pressure fluctuations, in efficient working.   Air puriging procedure : during normal operation measure the temperature and pressure at the outlet of condensor, check the saturation temperature for the same pressure from the P-T chart of the refrigerant. compare the measured temperature with saturation and adjust the condensor cooling water flow( considering the sub cooling of the refrigerant also) for achieving near saturation conditions inside the condensor. with condensor outlet valve closed and cooling water

viscosity : resistance of fluid to change its shape,due to the intermolecular forces causing a frictional drag effect. Absolute or dynamic viscosity = force to shear a fluid of area 1 m2 over another fluid of area 1m2 at the rate of 1m/s when the distance between two is 1 m.

HP cutout LP cutout Differential lube oil pressure cut out Relief valve in condensor Belt driven( belt will slip in over load) 

remove the tube flare, cut in between and remove through sides. Install new tubes and flare it using a flaring tool.flaring = 1/8th inch + tube diameter

Plug the leaking tube( max 10%), tube plates use devcon

Absorbs moisture in system, mainly contains silica gel or activated alumina, also contains charging connections

air locking, fouling and in multipass heat exchangers fluid bypassing due to holed division plates

1.check for leakages 2. assess the condition of sacrificial anodes(in case of non effective cathodes find the cause and correct). 3 check the conditions of bitumen or epoxy coatings for damages.

There are two solenoid valves on before TEV which shuts the valve when the compartment temperature is reached and another solenoid valve after evaporator which shuts if liquid is present in the line

To prevent carry over of lube oil as at low temperature separation is difficult,to maintain viscosity of lube oil and preventing flocculation of narrow passages with LO.

fluorescent sodium crystals are dissolved in water and viewed using uv light. Lube oil cooler, discoloration of sludge in the sea water side seen as dark patches and presence of oil globules.

To prevent contamination of refrigeration system by air and moisture as crankcase forms the suction chamber of the compressor, also there is no risk of crankcase explosion as no O2 will be available in the crankcase

Critical temperature- temperature above which a gas cannot be liquified how much pressure applied. Critical pressure- the pressure at which gas just liquify at critical temperature

functions- Lubricant Coolant

1 . Coating with bitumen-based paints or epoxy coatings 2. using rubber sheets to be bonded to mild steel or cast iron.

Reasons for liquid in suction line: 1. TEV stuck open 2. incorrect super heat setting 3. over charge

rapid boiling out of refrigerant from the compressor oil when pressure is suddenly reduced causing oil carry over causes : 1. liquid in suction line 2. crankcase heater not working 3. high superheat setting in tev 4. less lubricating oil

Lp controller - performs the switching on and of compressor if there is low pressure in compressor suc line due to the closure TEV since the required temperature is achieved in the evaporator,

Hydraulic pipe line are high pressure pipe lines and gaskets lose its credential after some time and fail.so they have square flange having metal to metal contact providing tight seal.pressures above 60 bar are always metal to metal sealing

type- welded or seamless, nominal pipe size- is the inside diameter rounded off, outside diameter,

Back pressure valve is a spring loaded non return valve fitted at the end of the evaporator whose temperature is set higher in a multi room fridge system . Function : 1. Create equlibrium of the system so that pressure of the gas at each compartmental exit vary. 2. Creates a back pressure on the evaporator coil so that no liquid leaves evaporator. 3. Makes sure that most of the liquid refrigerant is available to compartment with lesser temperature setting (  fluid always follow least resistant path, back- pressure valves put resistance in easier path so refrigerant exits always through the evaporator of the coldest room.)

1. light or heavy duty, 2. length of the drill(normal or extra length) 3.cutting angle(std 118 and 135)

Safety valves: it’s a pressure relief valve actuated by inlet static pressure and characterized by rapid action or pop up action.safety valves generally applies to valves protecting vessels where ther is a risk of explosion.the vent of a saftey valve is lead to a safe place.   Relief valves: Actuated by static inlet pressure and opens in proportional to the increase in pressure over the opening pressure.protecting vessels containg non expandable liquids which wont cause explosion. relif valve vents outside the valve

Annealing can remove stresses developed during cold working or during service so the elastic strains diminish and value of strength and toughness come back to their original value

Steel is an alloy of iron and other elements, including carbon. When carbon is the primary alloying element, its content in the steel is between 0.002% and 2.1% by weight.Bronze is typically 88% copper and 12% tin.

Hardness:resistance to abrasion Toughness:ability to absorb maximum energy before fracture Strength: ability to resist rupture Malleability: ability to deform plastically under tension.

A reamer is a type of rotary cutting tool used in metalworking. Precision reamers are designed to enlarge the size of a previously formed hole by a small amount but with a high degree of accuracy to leave smooth sides.

A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a

A special type of valve which prevents the passage of steam but allow condensate to flow  steam will be contained in the heating line until it condenses or give away its latent heat.

They are flap type non return valves used in scupper lines. It can be operated from above the bulk-head.

Its full bore, gives excellent flow characteristics and low pressure drop.the valve is also quick acting.

if change of direction is there valves are called angle valves, valve seats and lids are generally stelitted. It doesn’t give full bore and change of direction is also there so there is a drop in pressure. Sdnr type valves are used in bilge systems. This is to prevent back flow, so when testing for leak checks in bilge system remove valve lid and perform.                                                                                                           ...

The gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restric­tion is desired. The gate faces can form a wedge shape or they can be parallel. Gate valves are

It maintains downstream pressure within a range of flow, despite any change in supply pressure. There is spring versus steam or air equilibrium.

Resetting done by first closing and then opening, while opening v are compressing the spring and keep it on position by a retractable pin attached to an air cylinder which is retracted using an air signal during emergency

Gasket is used so that expensive machining is not required for mating parts

Minor leakage should be allowed for cooling. Its simple and reliable and tolerates poor conditions like off centered shafts. Replacing- clean stffing box with air, inspect stuffing box sleeve for wear, sufficient clearaces must be there,

Advantages :The advantages of the Pilgrim method are; that engine torque maybe transmitted without loading the key, where fitted.Also thrust produced is transmitted through a hydraulically pressurized nitrile tyre, which is applied to the propeller to force it onto the shaft. procedure- mounting, the surface must be dry

Stern tube bearings are generally lubricated by gravity feed systems or an electric driven pump or pump driven by a cam attached to the intermediate shaft. In tank system, it is placed at sufficient height to give sufficient heard to force lubricant into the bearing at all times. A pipe leads from the tank to the top of the s/t tube through the aft peak bulkhead. and a pipe run parallel to the supply pipe and return back to the gravity tank. There are temperature sensors also.  the minimum bearing length must be twice that of shaft diameter.

Procedure : Turn the engine to coincide the mark on the propeller with stem boss (for reference with previous measurements) or keep cyl 1 in TDC or methods followed on vessel or blades are numbered and designated blade is kept above. (A hole is made on the stern-frame boss,stern tube and bush during building of vessel.upper end of the hole is drilled to larger diameter and tapped out & closed using a screw plug) The

Rudder carrier bearing structure : The rudder carrier bearing takes the weight of the rudder on a grease lubricated thrust face. The rudderstock is located by the journal, also grease lubricated. Support for the bearing is provided by a doublers plate and steel chock. Wedge type side chocks, welded to the deck stiffening, locate the base of the carrier bearing. The carrier is of meehanite with a gunmetal thrust ring and bush. Carrier bearing components are split as necessary for removal or replacement. Screw down lubricators is fitted, and the grease used for lubrication is of a water resistant type (calcium soap based with graphite). reasons for conshaped contouring of thrust

Working : Four resistances balanced in Wheatstone bridge, fourth resistance is a hot filament kept inside combustion chamber, gases are drawn in by a aspirator and raise in temperature is recorded in the ammeter.

Calibration: a. SPAN Gas: - SPAN gas consists of 99.99% Nitrogen. As per it the O2 analyzer should show 0.01% oxygen b. The analyzer is kept in fresh air where it should show 20.97% oxygen.

integrally forged nitrialloy steel, hardened and ground finished.

Gear pump overhauling: check for any hard sediments or lacquer, check for clearance between rotor and casing. Check for non uniformity in contact resulting in improper wear caused by worn bearings.

A double volute casing to provide a rotational balance and this reduces wear on radial bearings.A diffuser ring is fitted to high-pressure centrifugal pumps to covert the kinetic energy into pressure, this ring is fixed in the casing around the impeller in such a way that passages are formed around the vanes.

Causes of reduced output of a centrifugal pump: worn wear ring,choked suction filter, air sucking in, lack of

Regular stopping and starting of compressor by the action of low pressure controller causes: under charge frosting or clogging of evaporator dirty suction strainer

Drop in pressure in suction side is greater than vapour pressure of liquid, possibility of liquid drawing vapour is there and vapour cavities are formed which moves to high pressure regions and collapses creating shock waves, which may result in errosion of parts.

NPSH- Net Positive Suction Head. It indicates the ability of a pump to deal fluids with low vapor pressure. its measured as head in meters.  Usually 7m @ 15 degree Celsius

1. Good miscibility and solubility with refrigerant. 2. low floc point and wax content. 3. thermal stability

Small & light for the volume of water they handle. Limited wear because very small contacts of metals.  Less maintenance and no lubrication needed.  Draw back is not self priming, but in case of sea water pumping

Lantern rings exist in pipe glands and connected to discharge side with a small pipe. The lantern ring is under pressure and acts very effectively as a seal and provides water for cooling and lubrication of gland.

Refrigerant properties : 1. low boiling point & low freezing point. 2.low specific heat and high latent heat (for higher refrigerating effect per kg of refrigerant) 3. working pressures must be optimum(cost & ingress of air) 4.high critical pressure and critical temperature(power requirements) 5.low specific volume

It’s the regulator b/w high pr and low pr side.The pressure drop across the tev causes the evaporating temperature of the refrigerant to drop to the temperature in evaporator. Imp functions 1. it prevents refrigerant in liquid state coming to compressor.

Overhauling imp points:  punch matching marks(parsies marks). Drain properly b4 opening pump. Renew gaskets and gland packing. Checks  1 check for corrosion, pitting and cavitation(repair using devcon or metal putty)  2.check for thrust and shaft bearings for damages 3.check wear ring clearances with feeler gauges or vernier. 4. check shaft sleeve for wear.

operation provided for effecting automated control on the varying load for refrigeration: 1.On/Off method: compressor is switched on or off in the absence of load. 2.Variable motor speed of the compressor.

A spiral bevel gear is a bevel gear with helical teeth.It is used in purifier motor drive where the direction of drive from the drive shaft must be turned 90 degrees to rotate the bowl. The helical design produces less vibration and noise than conventional straight-cut or spur-cut gear with straight teeth.A spiral bevel gear set should always be replaced in pairs i.e. both the left hand and right hand gears should be replaced together since the gears are manufactured and lapped in pairs. Material used for construction are generally hardened steels like carbonized nichrome steel.

Pump characteristics show a pumps performance capabilities in a graphical manner. After testing, the head,pump efficiency, power absorbed plotted in y axis and pumped volume in x axis.

Back Pressure shutdown - this measures the discharge oil pressure and alarms and initiates a shut down when below a set value. o Bowl not open - this may be done in several ways, typically by a lever switch operated by the discharged sludge hitting a striker plate. The other method is by measuring the motor current, when the bowl opens the bowl speed is dragged down due to friction effects of the discharging sludge and water. The motor current rises until full speed is re-established. This is detected by a current sensing relay

Freshwater pumps- cast iron casing with bronze interiors, bronze or stainless steel shafts, Seawater pumps- gun-metal casing with aliminium bronze impeller, stainless steeel casing.

1. The presence of a gravity disc in the purifier.  The interface or the line of separation between the oil and water is created using the gravity disc. The position of the gravity disc plays an important role in the generation of interface and thus in the purifying process process. For example, if the diameter of dam ring is large, the interface moves out towards the periphery and as a result some oil is discharged with water from the water outlet. Also, if the diameter is small, the interface formed will be more inwards and water will be discharged with the oil from the oil outlet. 2. Clarifier has a sealing ring wich seals the water outlet, as water and impurities remain in the until desludging. 3.The conical discs in a clarifier usually don’t have feed holes in them but if they do, then a disc without any holes is fitted at the bottom of the stack. 4. Sealing water is not present in clarifiers for the generation of a seal that prevents the oil to leave through the water outlet...

Liquid ring air primer pump- it consists of a bladed circular rotor shrouded on the under side, which rotates in an oval casing, which has a supply of sealing water, water is thrown outside by the impeller which whirls

Steam cannot be detected inside gauge glass but water can be. And effect of steam on water can also be seen. If steam is opened first, it will condense inside gauge showing water even if the water side

Sealing water low, Excessive back pressure Fuel temperature high or low Over sized gravity disc Orifice plat installed wrongly in the inlet side.

Boiler must be hydraulic pressure tested about 1.25 times the working pressure. Gag the safety valves and shut of the water gauges. Isolate and blank off parts which are not designed to withstand the pressure( attemperators or superheaters which are only designed to withstand differential pressure

Fill water drum with hot dearated water, initial dosing can be given through the upper manhole cover which is then replaced. Keep the air vent open and fill water upto 1/3rd level in gauge glass or until it shows up in the gauge glass. Check fuel oil system and start circulating diesel oil. start FD fan and

Attemporator is used to keep the temperatures of steam in the final stages to certain desired limits. This is to protect the super heater, generally two types one kept under the water level- water cooled,

1. to purge the air present in the boiler with steam 2. to cater for the expansion water after heating

Causes of scaling in evaporator: High evaporation temperature. High jacket water temperature. High production. Too much or too little sea water being supplied.

Since boiler water has to be supplied against already existing pressure inside steam drum.it requires a high pressure pump which can build around 25 bar n still be compact in size.hence multistage.In

Vacuum breaker valve is open. Volume of cooling water is insufficient. Leaks in any part of the unit. Air in condenser. Ejector not working weel. Air ejection valve stuck.

A Boiler Furnace is purged before burner operations to ensure that there is no unburned fuel or gases in the Furnace, which may cause a blow back.  Purging should be carried out for at least two minutes.

Alarms in Boiler: - a. Low water level Alarm b. Too low water level alarm. c. High water level alarm

1. less heat flowing in to the evaporator 2. air ingress in jacket water in evaporator. 3.High evaporator temperature and high condenser temperature. 4.Scaling or clogging of evaporator pipes.

• If too low water level alarm came, then check pump is developing correct pressure or not, it is working properly. • If tripped on high pressure, let the steam pressure come down.

Using a testing resistor to check salinity: Disconnect the probes and attach a spare resistor it should show a mentioned value in the salinometer (1.8 K

To keep feed water hot to prevent thermal shock in boiler, to observe oil leakage, feed water sould be

1.close all valves (distillate pump outlet, vaccum breaker,feed water valve) 2. pressure fresh water generator using flange with air connection attached through anode pocket and keep

If the diameter of a hole made in a boiler is more than 2.5t+75mm(t=thickness),the vessel should be compensated for the loss of strength by a stiffening ring around the hole circumfrentially called a