1.4 Auxiliary Equipment and maintenance work

Check valves should be installed wherever an undesired reversal of flow is possible. The two most common types are the swing check valve and the lift check valve. 

Stop valves are installed in the machineries , equipment and piping component for system operation, maintenance and overhaul and other damage control. There are four basic type of stop valves; Gate valve, Globe valve, Butterfly valve and Ball valve.

Gate valves provide a tight , reliable system up to the highest pressure and temperature. Especially suitable for high steam pressure steam service and hull valves in sea connection system. Gate valves are not suitable for throttling. 

Provided a tight, reliable shutoff for the full range of shipboard system. Compare with gate valves, they generally required a higher operation torque, but have a shorter stem travel and thus fewer hand wheel turns from open to shut.

Globe valve have the highest pressure loss of the four types of stop valves. Globe valve suitable for throttling and provided the best control characteristics of the four basic stop- valve types.  

Ball valve a relatively short - actuation mechanism and body length, and provided a more compact installation than globe valves. Ball valves stroke from open to shut with 90 Deg. Stem rotations, suitable where rapid operation or remote actuation with or without power is necessary. Ball valve should not be used throttling.

Butterfly valves are the most compact of the stop valves; they have relatively low pressure loss and provide quarter - turn operation as do ball valves. Butterfly valve intended for applications requiring tight shutoff or throttling.  Valve should close with clock wise rotation of the hand wheel or lever. During valve activating the valve operator must keep an eye on the indicator. (Shut – 1/4 – 1/2 – 3/4 – open)

Example – fuel tank stop valve must be closable from out side the machinery space to prevent fuel from feeding a fire.

Some valves are normal opened and some valves are normal closed in the engine room.

1. Some valves are operated from time to time and some valves are long time closed and opened. These valve spindle should be cleaned and greased depend on the type of the valve and long time closed or opened should be weekly manipulated.

2. During valve operating, the valve must have no leak. After activating valve wheel, checked valve spindle for leaking and if it is found that, tight gland nut evenly to stop the leakage.

3. No leaks detected at flange or else where

4. Insulation should be in placed and well fitted (if fitted)

Pumps on board the ships are used for suction, delivery, and transfer of any kind of liquids present on board of all types of vessel.  A pump is a machine used to transfer from one point to another point, alternatively it may simply provide the liquid with increase energy (potential) enabling it to flow or built up a pressure. The pump action can be achieved in various ways according to the type of pump employed. A pumping system on a ship will consist of, suction pipe, pump and delivery pipe & valve.

There are three main classes of pump in marine used. They are 

Positive displacement pumps

1. Reciprocating displacement pump

2. Rotary displacement pumps

Gear pumps rotate two identical gears against each other. One for driving and the other driven gear. As the teeth come into mesh, liquid flows into the pumps and is carried between the teeth and the casing to the discharge side of the pump. The teeth come back into mesh and the liquid force out

Screw pumps carry fluid in the spaces between the screw threads. The fluid is displacing axially as the screw mesh.

The figure showed three screw pumps. Multiple screw pumps have multiple screw threads. 

Displacement pumps are self priming pumps. A relief valve is always fitted between the suction and discharge chambers to protect the pump should it be operated with a valve closed in the discharge line.

When starting the pumps both suction and discharge valves must be opened. It is very important that no valves in the discharge line are closed. Other wise either the relief valve will lift or damage may occur to the pump when started. The pump is self priming, but where possible to reduce wear and risk of seizure it should be flooded with liquid before starting.

Depending on the supply head they may require positive displacement pump as priming device. Generally used for medium to high discharge rate, confined to low viscosity fluids.

Centrifugal pumps are nowadays most common used pumps on board the ships. The pumps main parts are Driving motor (mainly electro motor or other type), Pump casing , impeller , driving shaft , liquid inlet and discharge, bush (bearing) and sealing arrangement.

In the centrifugal pump liquid enters the center or eye of the impeller and flows radially out between the vanes.

Centrifugal pumps while suitable for most general marine duties, are not self priming and required some means of removing air from the suction pipe line and filling it with liquid.(see above sketch) (pump priming)

For the pump which is required to remove air from the suction pipeline needs the following starting procedure.When starting a centrifugal pump the suction valve is opened and the discharge valve let shut : then the motor is started and the priming unit will prime the suction line.Once the pump is primed the delivery valve can slowly opened and the quantity of liquid can be regulated by opening or closing the discharge valve.

Where the liquid to be pumped is at level higher than the pump, opening an air cock near the pump suction (Where the pump is stopped and usually the connection of the suction pressure gauge) will enable the air to be forced out as the pipeline filled up under the action of the gravity. When the pump is running the pressure gauge connection on the discharge line might disconnect to let the air vent out.

Common fault, such as no discharge, may be a result of valves in the system being shut or malfunction, suction strainer s blocked or other faults occurring in the priming system.

Air leak in the suction piping, a chocked impeller or too tight a shaft gland can lead to poor performance.

Reverse turning – Check that the ST-by pump is turning in reverse direction due to the discharge non return valve leakage.

Mechanical seal – Check mechanical seal during running and also stopping time, if found any leakage inform to duty engineer. Mechanical seal prevents leakage along the rotor shaft. They are leak free and eliminate possible health hazard. Do not require adjustment, do not require lubrication. When the seal does fail they may become leakage, require shutting down the pump and necessary to complete dismantled the pump to repair or replace a seal.

Gland Packing seal – Packing as sealing is still used in many rotary pumps, When application temperature exceed 260 deg. C, the type of packing should be considered. 

To adjust the packing, start the pump and tighten the gland nuts until the leakage is decrease to a tolerable minimum. Make sure gland nut are tightened evenly. Check the pump packing area to see if it is overheating, a little leakage is necessary to help lubricate and cooling the packing.

The engine room ratings should familiarize the following piping system.

• M.E and G.E F.O system

• Fuel oil system (Auxiliary boiler/Incinerator/Emergency generator)

• Fuel oil system (Transfer)

• Lube: oil system (transfer, purifying)

• Bilge, Fire fighting and G/S system

• Compress air system

• Cooling water system (main sea water)

• Cooling water system (Auxiliary sea water system)

• Fresh water cooling system

• Fresh water system (purifier operating water)

• Steam feed water and condensate system

• Service steam system

• Stern  tube system

The participant shall learn piping system by the aid of mimic panel from engine room simulator.

Piping and pumping system arranged so that water can be drawn from any ballast tank or the sea discharged to any other ballast tank or the sea.

Gland packing is a conventional shaft seal which is preferred by mechanical engineers. In certain applications, gland packing is preferred over mechanical seals, e.g., dealing with aggressive fluids. If there is any leakage, then it can be adjusted while the pump is in service.

• Identify types of joints used for pipe line and equipment having water, oil, air, steam, exhaust gases, and hot water. Identify type of packing material used for packing glands of valves or pumps for sea water, steam, and oil.

• Cut rubber or of stiff material suited for round or square flanges.

• Demonstrate procedures for cutting packing and for packing a gland.

• State precautions to be taken before commencing repair work on a pipeline or components in situ.

• Identify soft metal joints and ‘O’ rings and state care to be taken on these during maintenance

• Carry out temporary repair to a leaky pipe using clamps or jubilee clip.

A stuffing box or gland package is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.

Filter and strainer 

Mechanical separation of solid contaminations from oil system (fuel and Lube: oil), Fresh and sea water etc., is achieved by FILTERS AND STRAINERS.

Strainer is a coarse filter to remove the larger contaminating particles. Strainer usually employs a mesh screen, an assembly of closely packed metal plate, or wire coils which effectively block all except the smallest particles. Strainer is mostly used in the water systems (sea water, sewage plants, Fresh water generator, Sea water coolers, bilge and ballast system in engine room and hull).

Fine Filter (again in pairs) are used to removed smallest particles of dirt from oil before the oil enters the finely machine engine parts in either the fuel injection system or the bearings of the rotating machinery.

The term filter when applied to a fuel oil system refers to various arrangements. Usually all system have a transfer pump which is protected by a filter on the suction side to prevent large solid material from damaging the pump internally.

Most of nowadays filter have a fouling indicator at the housing- with increase differential pressure before and after the filter indicator change colour from white usually to red , indicating that the filter is fouled and need cleaning.   

Filter may be mounted in single or pairs (duplex) in which case one set up as standby.

In regard of cleaning

• Perodically manual cleaning

• Automatic self- cleaning (back flush)

• Automatic self cleaning with secondary filtering of waste drain fluid

• Disposal filter cartridges

• Centrifugal and special purpose filter

Stop the pump and close the valves before and after the filter

In case of heated filter housing shut-off the heating(steam/electric)

• Open venting plug to release the pressure (if any)on top of the filter cover or close to the top at the housing

• Open drain plug at the bottom or bottom sides

• Open the cover and take of the filter insert

• Remove all accumulated dirt/deposits in the housing and clean and dry the internal part of the housing

• Check for any damage/cracks or sign of corrosion/errosion etc

• Clean the filter insert, when cleaning the filter insert, it is very important to know the flow of the media through the filter in order to recognise where is the accumulated dirt at inside or out side the walls of the filter mesh- in order to perform proper cleaning.

• At first the heavy deposit can be brushed off and later can be finally cleaned by compresses air.It is recommended to keep some rags inside/outside the mesh to collect dirt/spray at the rag and to shift the dirt from one to another side of the filter mesh.

• Check carefully the filter insert for possible mechanical damages.

Procedure putting back the filter in operation 

• Check that nothing was left behind in the filter housing

• Insert the filter insert proper in place- if any gasket/or O-ring at the filter insert check the condition and if necessary renew

• Check the cover seat/gasket/O-ring before placing the cover and renew sealing if necessary

• Tight the cover ( avoid over tightening not to damage the sealing)

• Close the bottom drain plug

• Venting means it should be flooded with liquid and let the air escape through the venting plug. When all the air escapes, close the air venting plug and check the filter for any leaks.

• Start the heating (if any)

• Start the pump and check again for any leaks

• Additional venting can be performed after a certain time

Some type of units are used to automatic cleaning of the filter by back flushing

Once on board performing the daily duty an engine room ratings must know the media of filter / strainer to be cleaned and the method of cleaning.Some of the filter such as fuel oil, have normally heating arrangement which may cause heavy burnt if it is not handling carefully the filters.

For the ultrasonic cleaning a special container or tank is require,Ultrasonic device, special chemical and heating of solution might be applied ,so personal protection should wear such as goggle, mask,chemical protective glove,overall,safety shoes. Before handling chemical the person should read material safety data sheet.

Basic knowledge of Separator operation

Before start introducing the separators function we have to pass the basic principle of separation by gravity and centrifuge separation by centrifugal force.

Separations by gravity

Fuel on board is normally loaded into bunker storage tank, may be the double Bottom Storage tank or the other. The fuel transferred to the settling tank, where it is heated. (Always at least 10 deg C less then close flash point of the fuel) (Close flash point can see in the bunker specification from bunker supplier).Fuels which have been allow settling typically 24 hours. The flesh point of the fuel is the temperature of the fuel at which sufficient vapor is given off in the fuel tank “head space or ullage space” to ignite if the nicked flame is introduced. 

After completing separation by gravity in the settling tank the fuel is then pumped to the fuel oil service tank via centrifugal separator. The centrifuges may be set up as purifier and clarifier

Important – Never start dismantling until the bowl has come to complete standstill.

The heavy bowl pasts must be lifted by means of a hoist. Position the hoist very exactly. Use a lifting hook with catch.

Don’t place parts directly on the floor, but on a clean rubber mat, fiberboard or a suitable pallet 

All parts should be cleaned thoroughly by using suitable cleaning agent.

Soak the bowl discs in the suitable cleaning agent. Removing the separator disc stack and soaking in the solution of Disclean ( chemical, unitor). Removing separator discs and dismantling stack, then soaking discs in Disclean. (Read the material safety data sheet before using chemical).

Disclean may be used undiluted or diluted ,depending on the severity of contamination.( Should inform to responsible engineer before using chemical and necessary to understand Definition for using and Dosing rate)

After the unit or parts have been satisfactorily cleaned, they shall be rinsed thoroughly with fresh water to remove all traces of contamination and disclean.

Note – This product is not used on zinc, tin galvanized surfaces or anodized aluminum.

The person who handling chemical and cleaning must wear goggle, chemical protective glove, boiler suit and mask for protection respiration system. 

Never use steel wool, metal scraper to clean bow parts and discs.

Clean nozzle with a soft iron wire.

State functions of other auxiliaries and services such as sewage system, incinerators, refrigeration and air conditioning,

This equipment is used for prevention of pollution by sewage.

MARPOL 73/78 ANNEX IV: Regulation for the prevention of pollution by sewage from ship.

Direct overboard discharge valve must be closed and locked, when sewage is discharged through sewage treatment plant.

This equipment is operated by responsible engineer and 

Watch man should check chemical tank level and dosing pump condition. If chemical tank is coming low level, necessary to fill by recommended chemical and amount of filling chemical must be recorded and should inform to duty engineer.

Watch man should check blower running condition

Watch man should check overboard discharge pump running condition. If pump is running continuously, that means fresh water has been leaked some where, should inform to duty engineer and necessary to check this leakage.

• Check High level alarm

• Check pump mode is manual or auto

Segregated garbage and solid wastes generated onboard are burn in the incinerator. It is constructed of heavy and well-insulated materials to keep the high levels of heat inside the furnace so that the waste is burned quickly and efficiently. 

For the preservation of foods onboard for the consumption of crew, provision refrigerating machine is installed. It provides cooling to freeze and chill meat, fish, vegetables and other products.

Air conditioning plant provides conditioned air to the ships accommodation to make it habitable. The system continuously provides and maintains clean, temperature and humid controlled condition air in the ships cabin, offices and the bridge. 

Oil and water mixture in the engine room bilge system is processed in the Oily water separator, and it separates oil and water mixture into a clean effluent before being discharge into the sea (max. 15 ppm as per MARPOL 73/78 Regulation). The device is one of the most important equipment for environmental protection. It is categorized as “Critical Machinery” onboard.

This equipment is used for prevension of pollution by oil.

• MARPOL 73/78 ANNEX 1: Regulation for the prevention of pollution by oil from ship.

• Engine room bilge water must be pumped out overboard through oily water separator.

• This equipment should be operated by responsible engineer.

• The area of this equipment must be cleaned all the time and the suction filter needs cleaning.

• The overboard discharge valve from oily water separator must be closed and locked except running. 

Fresh water generator or “Distilling Plant” generates fresh water onboard. Fresh water is produced by boiling the sea water and condensing into fresh water. Primary heating used is the jacket cooling water of the main engine.

Safe handling of steam boiler

Basic knowledge of component

Boilers are closed vessel containing water, which by the application of heat, is converted into steam at any design pressure. This steam is used for the production of useful work.

Burning residual fuel is utilized in a boiler to raise steam.

The two types of boiler based on their working principle are Fire tube and water tube boiler.

Fire tube – consists of large tubes for low pressure heating plants and the products of combustion the inside of the tube is surrounded by water.

Water tube- constructed with small tube efficient production with high steam pressure, where the water is contained inside the tube, where the product of combustion passing around the out side of the tube.

Exhaust Gas Economizer (EGE) is a device used to generate steam by using waste heat from the exhaust gas outlet casing of the main engine (diesel engine) and considered as waste heat regenerative equipment onboard.

The device is made of a casing and the tubes (fin type or bare type) and arranged either horizontally or vertically in the casing. Commonly, the tubes are arranged in bundle or groups and can be removed panel to panel. The casing is reinforced so that it can withstand the pulsing of exhaust gas from the main engine and the vibration of the ships. It has manholes and inspection holes to perform inspections and cleaning maintenance as necessary. The casing is covered with heat insulators and lagging.

A circulation line for feed water is provided either from a separate steam and water drum or an attached drum. Two units of boiler circulating pumps are connected, one as in operation unit and the other as stand-by unit. Steam generated is separated by the steam drum and supplied directly to the applicable equipment.

(2) Evaporator/ Fresh water generator heating media

(3) General cleaning

(4) For boiler soot blowing and for the steam atomized burner

(5) Fire fighting as used in steam smothering system

(6) Main engine jacket F.W preheated and lube oil sump and drain tanks

(7) Use in the waste oil, incinerator, slop tanks

• Clean oil tray and check leakages, if it is found, should inform to duty engineer

• Check both side water level gauge , both gauge glass level must be the same level

• Check water level of condensation tank and the condition of water, if oil tank heating coil are leaked, the leaked oil can see at the observation tank sight glass. Open tank cover every day and check water surface for vestiges of oil. Check water surface through sight glasses about vestiges of oil on any watch round in the engine room.

• Check steam pressure

• Safety valves are installed on top of the boiler to protect it from overpressure. Two safety valves are fitted on the steam drum. 

Boiler steam pressure can read in the control room and near the boiler. Duty watch man should check steam pressure on the pressure gauge and should know the set point of low steam pressure alarm and high steam pressure alarm.

A ships propeller shaft transmits mechanical energy from the main engine to the propeller. When there is more than one transmission element, the propeller shaft is a kind of shafting line. Applications. The main function of the propeller shaft is to turn the propeller.

Use Chipping hammer, wire brush and power tools in removing rust

Proper surface for painting, cleaning and degreasing

Paint surface using paint brushes, roller

Engine room and equipment cleanliness is of vital important. Engine room floors and walls should be cleaned. Wipe up the floor and floor plate and also wipe up engine room equipment for safety. Don’t forget “Safety First”.

Use rags on a sequence of job, starting from the fine machinery  where only a perfectly clean rag will do and passing through dirtier task, until the rags ends up as something which to wipe up oily floor or  tray  like that. Necessary to prepare clean rags container, dirty rags container, Oily rags container with cover.  

By using mop or rags with a bucket of water using proportion of soap or cleaning detergent and fresh water. After using mop and rags, it should be washed and kept dry for the next use.

Look around for any electrical outlet boxes near the job and then you may short-circuit them. Look also any hot surface other dangerous spots, so that you can avoid touching them.

Safety

Do not wipe any moving, hot, or electrically charged machinery, otherwise you may lose one of your hands or even your life.

During cleaning Safety precaution should be taken and prepared in advance. In case of elevated area or high area a suitable ladder should be fitted safely secured. Personal should wear adequate safety equipment such as, safety belt, helmet, goggle, mask, overall and safety shoes. 

Bilge

Do not drop rags into bilge as they may clog the bilge pump. The bilge area should clean and dry, so that any leakage can find easily. 

Housekeeping

Housekeeping mean handling and storing of all kind of store spare and tools on board the ship.

Handling of store

Store can be divided into deck store, engine store, electrical store and catering and galley store.

Every ship has designated space for keeping store in proper and safe condition. The engine crew should know the location of the engine store and the positions of each store.

The engine ratings must have enough knowledge, how to assist engineer when receiving store. Once received from the supplier the store should be transferred to the place e.g. Engine room and checked according to the list. The store should be checked very accurately for the quantity and quality.

If any mistake found out, it should be immediately informed to the Engineer to return to the supplier.

After checking the store, it should be stored safely in the designated space. All departmental crew should know where to keep and where to find any of the store items when requested by superior. Store should not be used without the knowledge of the person who is in charge or responsible for handling store. (In the engine room usually 2ND Engineer).

Consumable Store

Such as chemical store, gases (oxygen, acetylene, refrigerants) store, Lubrication oil and grease store, paint store. Consumable should be stored strictly and only in designated spaces for respective consumable and should not be mixed with other store and consumable.

Storing of consumable out of designated space can lead to major non-conformities in case of flag state or port authority inspection on board. 

Handling of spare

Spare parts are usually stored and kept in the spare parts room which is a part of the engine room and located in the engine room casing. Big spare parts are lashed normally close to the place where it should be used (M/E Piston, M/E liner, M/E Cylinder head)

Handling of tools

There are several kinds of tools on board and generally can be group as

• Hand tools

• Electric tools

• Hydraulic tools

• Pneumatic tools

• Special tools (usually by maker for their specific equipment)

Tools are used practically everybody on board. It is very important to know how to use correctly the tools and where to use appropriate tools depend on the job assigned and nature of job to be performed. 

For electric tools and extension light, it is important to check that electric wire are not thorn or damaged and connections are in good order. Extension cable must have bulb cover and handle must be in good order. After using this, checked and cleaned carefully and put it back to the corrected position to be readiness for the next use.

Pneumatic tools, it is important to check the air hose is not leaking to lose of air and causing air compressors to work more than necessary.

At the hydraulic tools it is also very important to properly check the oil hose for leaks, Hydraulic tools normally use hydraulic oil under high pressure which can, if the hose is leaking ,spray over hot areas or electric equipment leading fire or explosion, leading to injuries.

After using any kind of tools, the tools should be cleaned, checked for any damage and stored in the original place safely.