Maintenance Steam Boiler

A. Understanding Boilers
The boiler in the engine room of a ship is one of several auxiliary planes on board. The function of the Boiler is a closed vessel, which can form steam with a pressure of more than 1 atmosphere, that is by heating the kettle water in it from hot gases from the combustion results. In general, two Boilers which have a purpose if the boiler is damaged or under repair, there are still others that can replace it.
Boilers on the ship are of two types, namely:
Fire pipe boilers where the ignition process occurs in the pipe, then the heat generated is delivered directly into the boiler containing water.
Water pipe boilers where the ignition process takes place outside the pipe, then the heat produced heats the pipe that contains water, where in this water pipe the flowing water must be conditioned on the mineral or other content which is soluble in the water.

1. Boiler Equipment
Various valves and tools are installed on the skin or boiler tubes. Figure A.1, illustrates an example of the type and arrangement of equipment installed in a tube kettle.

Equipment on the tube kettle
(1) Main steam usage valve (Main steam stop valve)
(2) Auxiliary water feed valve
(3) Main water feed valve
(4) Auxiliary water feed valve
(5) Security valve (Safety valve)
(6) Water gauge
(7) Pressure gauge (Pressure gauge)
(8) Surface blow off valve
(9) Foam room (Scum pan)
(10) Blowing valve (Boiler bottom Blow off valve)
(11) The blowing out of the ship (Ship side blow off blow off cock)
(12) Salino meter (salinometer cock)
(13) (Hydrokineter)

a. Steam stop valve.
This valve flows steam from the kettle. There is a main steam valve for flowing steam main engines and auxiliary steam valves for auxiliary engines. show steam valve
.
1 Valve (Valve)
(2). Valve seat
(3). Valve rod (Valve rod)
(4). Valve body (Valve body)
(5). Valve Cover (Valve cover)
(6). Retaining Bolts (Yoke)
(7). Player (krank)

b. Filling valve (Water feed valve).
Is a valve that regulates the amount of water that is loaded into the kettle. In addition to the water valve (water stop valve) there is also a filling check valve to prevent backflow from the kettle. Figure A.3. shows the water fill valve where (A) is a water retaining valve and (B) the filling regulating valve.

c. Safety Valve
Is a valve to maintain the safety of the boiler by releasing steam automatically if the vapor pressure in the kettle exceeds the specified value. Figure A.4, showing a safety valve.

A. Valve (Valve)
B. Flow hole (drain hole)
C. Valve needle (valve spindle)
D. Per (spring)
E. Cotter (small space)
F. Cover
G. Tubes
L.N. Valve lifting equipment (device of lifting valve)
S. Adjusting nut

d. Water gauge.
Is a tool to show the water level in the kettle. There are various types. If the surface of the water in the kettle is too low, the surface of the heater will overheat so it is dangerous. Conversely, if it is too high, the steam will be mixed with drops of water so that it disrupts the running of the engine. Therefore, the water level must be kept at a normal height.

e. Pressure gauge (pressure gauge)
Is a tool to show the vapor pressure in the kettle. In general, bourdon tube gauges are used

Other valves.
In addition to the valves mentioned above, the boiler is also equipped with a discharge valve (blow off valve) to remove impurities from the boiler water, salino meter valve to take samples of water boiler for inspection, air purge valve and control valve for sirens or steam distiller.

2. Combustion and water supply equipment
a. Combustion Equipment
At present, the fuel used is heavy oil. To burn it, the oil needs to be emitted first by a brand (oil burner) and then mixed with air.

A, 8 shows a diagram of “heavy oil” combustion equipment.
Picture: A.8. Oil burning equipment
(1). Double bottom tank
(2). Fuel transfer pump (Fuel transfer pump)
(3). Inventory tanks (Settling tanks)
(4). Spout valve (Drain valve)
(5). Cold oil filter (Cold oil fitter)
(6). Oil burning pump
(7). Oil heater (oil heater)
(8). Hot oil filter (Heated oil filter)
(9). Burners (Burners)
(10). Circulating pipe (Circulating pipe)

1) Supply tank (settling tank)
In this tank the water content in the oil is separated and deposited by heating and then silencing it. There are two settling tanks that can be used interchangeably.
2) Filter
This filter functions to filter out impurities contained in oil. There are two filters, one is placed in front of the oil combustion pump and the other is behind the oil heater.
3) Brander pump (oil burning pump)
Pump to put pressure on oil decomposition. There are two pumps but one as a replacement pump.
4) Oil heaters
This heater serves to reduce the viscosity of oil through heating so that it decomposes.

5) Burner
Burners break down oil and spray it into the furnace to burn. Figure A, 9 shows how to place a brander in a combustion pit.

(1) Burners (Burners)
(2) Air (Water)
(3) Suduantar (Guide blade)
(4) Air (Water)

A.09 Installation of Burners

6) Air feeder
The air flowing from a fan through the precursor heater, up to the furnace is rotated by interconnecting blades (guide blades) surrounded by the combustion chamber, and then mixed with the decomposed oil. The amount of air is regulated by a regulator.
b. Water Supply Equipment
The vapor generated in the kettle is utilized by the machine and condensed into water by a condenser. The equipment for supplying the condensed water returns to the kettle. This equipment can be open or closed type.

A.10. Water supply equipment.
(a). Steam engine (Steam engine)
(1) Boilers
(2) LO Heater
(3) Heater FO
(4) Free Heater Fresh Water Main Engine
(5) Condensors
(6) Expansion Tank
(7) Charging Auxiliary Tank
(8) Charging pump
(9) Charging Water
1) Charging pump
The filling pump is a pump to fill water into the kettle. This pump is the most important part of water supply equipment, usually there are two pumps, one as inventory.
2) Filter and fill water tank
Open type water supply equipment is equipped with a filter to separate oil or other impurities. Usually a tank with a water filter is used in the fill water tank. The filling water tank functions to adjust to not balance at any time between the amount of condensed water and filling water.

A.11 Adjacent tanks (Cascade tanks)
1. Condensate water inlet
2. Division plate (Division plate)
3. Filter (backet filter)
4. Float chamber
5. Float (Float)
6. Control valve of steam filling pump (Steam regulating valve for feed pump)

3) Filling water tanks help
Charging water will be used and may be lacking due to leakage or other things. This tank stores fresh water or distilled water to fill the deficiency.

c. Working Principle of Boiler
Basically the working principle of a boiler is that if water is heated at a pressure of one atmosphere, the temperature will gradually rise to 100 ° C. But further heating will not raise the temperature higher. The water will boil and all that is added is used to generate steam. So the vapor pressure produced is 1 atmosphere and the temperature is 100 ° C. However, if the water is heated at a pressure greater than 1 atmosphere, the temperature will rise to higher than 100 ° C and the water will boil at a temperature that is proportional to the pressure. After boiling, the temperature will not increase by further heating and all heat is only used to form steam.

A certain temperature that is proportional to the pressure is called the saturated temperature (saturation temperature) and the pressure is called saturation pressure. Between saturated temperature and saturated pressure there is a definite relationship so that if the pressure is known, the comparable saturated temperature is certainly not enough. Similarly, if the temperature is known, a comparable saturation pressure is also known. Steam generated at saturated pressure and saturated temperature is called saturated steam. label B.1. shows the relationship between pressure and saturated steam temperature.

Saturated vapor usually contains a quantity of water, so-called saturated steam is wet, steam which does not contain water at all (because it has evaporated all) is called dry saturated steam. If dry saturated steam is heated further at saturated pressure, the temperature will rise above the saturated temperature with an increase in the volume of steam called superheated steam,
The heat added to increase the temperature to the boiling point is called real heat and heat which is added after the boiling point is reached and used to generate steam called latent heat.

Tabel C.1. Tekanan dan suhu uap jenuh.

Tekanan kg/cm²

Suhu

°C

Tekanan kg/ cm²

Suhu

°C

Tekanan kg/ cm²

Suhu °C

Tekanan kg/ cm²

Suhu °C

Tekanan kg/ cm²

Suhu °C

0.01

0.05

0.1

0.5

1.0

2.0

6.7

32.5

45.4

80.9

99.1

119.6

3.0

4.0

5.0

6.0

7.0

8.0

132.9

142.9

151.1

158.1

164.2

169.6

9.0

174.5

179.5

187.5

194.1

200.4

206.1

211.4

222.9

232.8

241.4

249.2

262.7

100

225.65

274.3

284.5

293.6

301.9

309.5

374.15

d. Water Boiler Care
Water is a useful and inexpensive medium for heat conduction into a process. The quality of steam produced in the boiler system is affected by proper water treatment. The quality of water supplied to the boiler also affects the operating efficiency and age of the boiler.
Water contains various dissolved substances such as minerals, mixed gases and foreign objects such as dirt and so on. If there is an increase in heat and pressure on water, almost all dissolved materials will separate from the solution into solid particles which, if left unchecked, will form sediment and water crust. Boiler water must be free of solid deposits so that heat transfer processes occur quickly and efficiently.

1) Oxygen scavenger
The chemical oxygen scavenger is often added to a deaerated feed water boiler to remove the residual oxygen that was not removed by the deaerator. The oxygen scavenger that is often used is sodium sulfite (Na2SO3). This is effective and quickly reacts with oxygen to form non-scaling sodium sulfate (Na2SO4). Another commonly used oxygen scavenger is hydrazine (N2H4).
Other Scavenger includes 1,3-diaminourea (also known as carbohydrazide), Di Ethyl Hydroxyl Amine (DEHA), Ni Trilo Acetic acid (NTA), Ethylene Diamine Tetra Acetic acid (EDTA), and Hydroquinone.
2) Definition of Dealkalisation
Dealkaliasation of water refers to the removal of alkalinity ions from water. Chloride anion cycle ion exchange dealkalisers removes alkalinity from water.
The Chloride cycle dealkalisers operate similar to the cation cycles of sodium water softeners. Like water softeners, dealkalisers contain ion exchange resins which are regenerated with concentrated salt (brine) solutions – NaCl. In the case of water softeners, cation exchange resins are exchanges of sodium (Na NaCl ions) for hardness of minerals such as calcium and magnesium.
Dealkaliser A contains the basis of a strong anion exchange resin that exchanges chlorides (Cl ions from NaCl) for carbonates, bicarbonates and sulfates. When water passes through anion resin, carbonate ion, bicarbonate and sulfate are exchanged for chloride ions.

e. Corrosion Control System in Boilers
Corrosion in low pressure boilers can be caused by dissolved oxygen, acidity and excessive alkalinity. Water treatment must therefore remove dissolved oxygen and maintain boiler water with the right pH and alkalinity level. Water oxygen content decreases with increasing temperature as shown in this graph.

A graph that shows how temperature affects the level of dissolved oxygen in feed water. Therefore the following, which only increases the temperature of feed water, and provides enough oxygen to escape, will significantly reduce the risk of oxygen corrosion. Thus, a feedtank designed or Hotwell is the first line of defense in protecting the boiler.
Note in particular that cold make-up and back condensate must be distributed by spraying arrangements to ensure thorough mixing and avoiding temperature stratification. This will encourage maximum de-aeration effect.
The temperature of the feed tank must be maintained at least 80 ° C. This must be achieved by returning as much condensate heat as possible and by steam injection. A feed temperature of 85-90 ° C is ideal, but must avoid pushing the temperature too high, because it will encourage damage to cavitation in the feed pump.
NB: excessive temperature, steaming and “banging” on Hotwell can be an indication that steam traps are passing and allowing the steam to come back to life. This must be investigated immediately, because it can waste a lot of heat energy.
Routine boiler water testing is important to ensure that chemical oxygen scavenger reserves are well maintained at all times. Condensate Corrosion Control System. The condensate line shows carbon dioxide corrosion.
Dry steam is not corrosive, but again condenses to form water, can absorb corrosive gases, oxygen and carbon dioxide, which if not treated accurately can cause failure again in the condensate line. The first place to fail at the condensate line tends to be thread and elbow and the rate of natural corrosion will tend to increase where the alkalinity of raw water and carbon dioxide is high. Oxygen corrosion, which leads to pin-holing of the condensate line, can usually be controlled by adding an effective chemical oxygen scavenger to boiler feed water.

Carbon dioxide corrosion, which causes the loss of uniform metals below the water line caused by acid attacks, can be controlled either by pre-treatment techniques such as de-alkalisation and reverse osmosis, or by the addition of special volatile chemical vapors such as neutralizing and filming amines. Depending on their nature, these chemicals can also be closed into boiler feed water or injected directly into the steam header.

1) Steam Boiler Blowdown
The purpose of a blowdown steam boiler is to remove mud, suspended solids and dissolved solids. Sludge is formed with either precipitated hard salt or corrosion products brought back from the condensate system. A sudden increase in the level of mud can indicate that there are problems with water softeners or condensate contamination.
Blowdown is important for removing mud and maintaining steam purity but it is important to ensure that blowdown needs to be avoided because of energy waste. Depending on boiler blowdown pressure every 3-4% is equivalent to 1% of fuel costs.
2) Causes of Corrosion in Boilers

a) Corrosion is caused by boiler water
Corrosion will occur in the part where water is applied continuously if the smoke funnel is above the combustion chamber and shows the water pipe to the combustion chamber, when some corrosion occurs immediately overcome with chemical reactions, when the reaction is rapid then corrosion does not take root. If, however, washing with a chemical reaction will slow down the corrosion. Some of the causes of corrosion are negligence in the blow off, not cleaning the cleaning in the boiler, insufficient circulation of boiler water and excessive use.

b) Corrosion caused by other substances
Gas reaction in boiler water
Iron rusts or corrodes due to submerged in water or high temperatures and the use of corrosive materials. In this case the oxygen contained in the water supply is very good for burial or perforation, this happens in the steam room where there is a lack of change of water, the running of the water from the boiler drum and pipes, water pipes and economiser. Carbon acid results from carbon dioxides when dissolving in water and reacting with iron to produce carbon iron. Carbon iron reacts with oxygen to produce a second iron oxide. Since this reaction process takes place where carbon dioxide is liberated, thereby accelerating other corrosion cycles.

c) Corrosion by nature
One part of perforation or perforation, expansion of the coring area is caused by the separation of acids in boiler water and the separation of large / fat acids from animals or woven plants in boiler water.
d) Corrosion by salt
Corrosion of magnesium chloride in the boiler occurs until rooted. This is due to the separation of the results of hydrochloric acid in boiler water and this does not stop in perforation but stops in the form of fish scale scales do expansion, which often occurs in parts showing for strong heat where air bubbles are difficult to release.
e) Corrosion by excessive heat vapor.
Steam is a separator in hydrogen and oxygen when the temperature of the steel surface rises to centrigrade 400 degrees or higher. Oxygen is the corrosion section of a steel section.

f. Treatment of Boilers
1) Check the amount of water in the expansion tank
If the amount of water in the expansion tank decreases, the actions that must be taken are as follows:
– Open the faucet on the inlet pipe pup that goes to the expansion tank
– Make sure the faucet on the inlet pump pipe is open
– Run the filling pump
– Look at the glass suspected at the expansion of the tank, make sure the water level does not exceed the allowable limit
– After the amount of filling water is enough, turn off the pump
– Close the faucets that have been opened to their original position
2) Burner care

Components that must be cleaned include:
– Cleaning of fuel filters from dirt
– Cleaning electrodes and adjusting distance
– Cleaning chell photos from soot
– Cleaning the nozzle from dirt so that fuel spraying can be perfect
– Electromotor checking

3) Feed Pump Maintenance
– Cleaning impellers from mud or dirt entering
– Mechanical seal check
– Examination of ball bearings
– Add lubricants to ball bearings

4) Check PH levels in filling water
Pengechekan the pH level in the filling water is to find out the water is acidic, neutral or alkaline. The ways to find out PH are as follows:
– Using a PH meter tool,
PH meter is a device used to measure acidity and acidity, acidity in the solution is expressed as the level of hydrogen ions (H +), in other words PH is a measure of the strength of an acid. PH of a solution can be assessed in several ways, among others, by way of titrating the solution with acid and a more accurate indicator by using PH meters, measuring the pH level of acid and alkaline water works digitally, PH acid water if less than 7 and PH alkaline if more than 7, PH water is called neutral if PH is equal to

7 – Using litmus paper
In addition to using PH meters, the detection of basal acid accuracy can be done by using litmus paper in a simple way, as for the method is the color of litmus paper in an acid solution, alkaline solution, and a different neutral solution. There are 2 kinds of litmus paper, namely red litmus and blue litmus. The properties of each litmus paper are as follows:

(a) The red Lakmus in the acid solution is red and in the base solution is blue and in the net solution is red.
(b) Blue Lakmus in a red acid solution and in a blue base solution and in a neutral blue solution
(c) Red methyl in an acidic solution is red and in an alkaline solution yellow and in a neutral yellow solution.
(d) Orange methyl in an acidic solution is red in a yellow base solution and in a neutral yellow solution.
(e) Phenolphthalime in a tinted acid solution while in a base solution it is red and in a neutral colored solution

– Here are the general characteristics of the solution in water:
Common characteristics of acid solutions are: sour taste, corrosive, can redden blue litmus paper, solution in water can conduct electric current, causing metal solidification (corrosion)
Common characteristics of alkaline solutions are: bitter taste, slippery, can mute red litmus paper, solution in water can conduct an electric current, if it hits the skin the skin will blister (caustic)

5) Alkalinity Test
a) Calculating P-Alkalinity range: 0 – 300 mg / l
(1) Use a small measuring cup, open the lid, rinse with water for example: fill with 5 ml of sample water then cover.
(2) Add 1 drop of “Phenolphtalein Indicator” through the hole in the measuring cup lid, stirring by shaking the measuring cup, if the solution is yellow means P-Alkalinity = 0. If the purple solution proceed with titration using HI 3811-0 solution.
(3) Take HI 3811-0 solution using a syringe (such as a syringe) to the scale = 0.
(4) Drop into a measuring cup drop by drop.
(5) P-Alkalinity results are seen from the scale of reagent use in the titration pipette, then multiplied by factor = 300 to get the yield of mg / l (ppm) CaCO3

b) Range: 0-100 mg / l (ppm) CaCO3
Do this method if the results obtained are smaller than 100 mg / L to get more accurate results.
(1) Use a large measuring cup, open the lid, rinse with sample water then fill with: 15 ml of sample water.
(2) Continue the titration process with the same step points 1 to 5 as above.
(3) Read the mark on the pipette and multiply it by a factor of 100 to get the mg / L number of CaCO3.

6) Chloride Test
a) High Range (0-1000) mg / LCl
(1) Take a small measuring cup. Rinse the measuring cup with an example of water, fill the measuring cup with a sample of water until the mark.
(2) Drop 2 drops of Diphenylcarbazone through the hole in the lid of the measuring cup, then shake the measuring cup to mix the solution until the color of the solution becomes purplish red.
(3) While still stirring (shaking) the measuring cup, add the nitric acid solution until the solution turns yellow.
(4) Take a titration sprayer (such as a syringe), insert the needle into the H3813 mercury nitrite solution, then take the solution until the pushing rubber on the tarpaulin: 0 ml.
(5) Insert the titration pipette needle through the hole, closed the measuring cup. Perform titration until the solution in the measuring cup changes color from yellow to purple.
(6) Read the mark on the spray needle (titration pipette), multiply by 1000 to get the number mgr / l chlorite.

b) Low range (0-100) mg / LCl
Do this method if the results obtained are smaller than 100 mg / l clorite to get more accurate results.
(1) Use a large measuring cup, open the lid, rinse with sample water then fill with: 50 ml of sample water.
(2) Continue as a test for the high range range.
(3) Read the mark on the pipette and multiply 100 to get the mg / l chlorite number.

7) sulfite test
a) High range (0 – 200) mg / l Na2SO3
(1) Open the lid of a small plastic container, rinse with sample water. Fill the measuring cup with sample water until the tera: 5 ml then cover.
(2) Put 4 drops of sulfamide acid solution and edta through the hole in the lid of the plastic container and shake it properly so it can dissolve completely.
(3) Put 2 drops of sulfuride acid solution, shake again properly.
(4) Add 1 drop of starch indicator, shake it back properly.
(5) Take a titration sprayer (such as a syringe), insert the needle into the titrant reagent solution Hl3822-0 then take the solution until the rubber pushes on the tarpaulin: 0 ml
(6) Insert the titration needle through the hole closed with a measuring cup, do titration until the solution in the measuring cup turns blue.
(7) Read the numbers printed on the spray needle (titration pipette), multiply by 200 to get the mg / l number of sodium sulfide.

b) Low range (0 – 20) mg / l Na2SO3
Do this method if the results obtained are smaller than (0 – 20) mg / l Na2SO2 to get more accurate results.
(1) Use a large measuring cup, open the lid, rinse with sample water then fill with: 50 ml of sample water.
(2) Continue processes such as tests for the high range range.
(3) Read the mark on the pipette then multiply 20 to get the number mg / l (ppm) sodium sulfide.

g. Boiler Maintenance During Operation Period
Boilers will not be able to live long if they are not carried out carefully (intensively), both during operation and during storage. Careful maintenance in the intended operating period is how to operate the steam boiler in accordance with applicable instructions or in accordance with the design of the boiler maker.
Besides that, the use of feed water must also be appropriate or qualify as kettle filler water. What is clear is that boiler fill water must be different from substances that can damage the boiler, both corrosion and scale.

To prevent this, an external treatment and internal treatment is carried out, for example a PH control is installed on a condensate line, or Water treatment is done for raw water, as well as chemical injection in the feed water and boiler water.To find out that the properties of water have met the requirements, intensive water and boiler water research has been carried out in the laboratory. By keeping the numbers presented as fill water from boiler water it also helps to use long-lived boilers. The limit standards for boiler water are:

Table 3.5 Limit standards for Water boilers

PH	10,8-11,3


Total hardness (ppm)	Tracess
O alkalinity (ppm)	200
Sulphite (ppm)	20-40

h. Boiler Maintenance During After Operation Period
No less important is the maintenance of boilers after the operation period compared to the period during the operation. Because after all the metal will be easily damaged by substances that destroy metals, such as oxygen etc.
Moreover, the steam valve that will be stored for a long period of time, it must get proper care. The first step taken after the boiler has been operating for several months and will be stored long enough is chemical cleaning and mechanical cleaning, while injecting the chemical into the boiler for injecting the chemical cleaning process, namely:
1) Two days before the boiler is turned off, then the type of chemical that has been determined and the dosage begins to be injected by monitoring the pH of the boiler water should not be more than 13.
2) Blow Down lower drums are routinely carried out to remove dirt that has settled
3) After two days of injecting the chemical, the boiler is activated and then the water circulation / replacement of the filler water is carried out.
4) After the boiler is cold, the boiler water is blown (emptied)
5) Examination by Depnaker is held, to determine the things that need to be carried out in the next step for example in mechanical treatment Cleansing inside and outside of the boiler section.
6) After cleaning both the outside and the inside of which it is carried out by requiring time, it will be carried out again by the Department of Labor, to determine whether it is still necessary to do re-cleaning or not.

i. Inspection and Repair
Examination of the steam valve is done in two ways, namely:
1) Inspections conducted by the Department of Labor
namely steam drums, water drums, superheater tubes, cleanliness, material strength, maerial conditions and Water Tube. These parts are certainly associated with high-pressure parts that are very dangerous for human safety.
2) Examination carried out by the company, namely parts that are not high pressure, which part is associated with productivity and things that disrupt the efficiency of the boiler for example on the fuel frame, wall boilers, impellers, dampers, insulation etc.

After both parties determine which parts need repairs and replacements, the repair starts at:
a. Replacement of water pipes.
b. Replacement of steam pipes
c. Replacement of gas pipes
d. Repair of stone walls
e. Repair casing
f. Impeller Repair
g. Insulation
If the repair work is completed, then the third inspection will be carried out by the Department of Labor and the company.

j. Hydrostatic test
To determine that the boiler meets the requirements to be operated, a hydrostatic test is performed. hydrostatic test that is the solidification treatment of the boiler using cold and clean water to find out and ensure that the boiler is in a state of not leaking both on the valve, packing and pipe. The correct compaction method is:
1) The boiler is empty, the drain-drain valve is tightly closed, the valve is shut off, the main steam steam valve is closed, the vent valve steam drum and the superheater are fully opened.
2) Run the Water feed pump with small openings, with the condition of the fill water that meets the requirements.
3) After the boiler water is full so that the water spills through the vent valve, and make sure that the air is gone, turn off the pump and close the vent valve.
4) Run a special compaction pump, with a small capacity (determined), to get the pressure rise slowly
5) The increase in pressure on the pemadata is 10% of the allowable working pressure. The testing pressure (compaction) allowed is:
a) Working pressure is less than or equal to 5 kg / cm2, then compaction pressure = 2 times the working pressure.
b) Working pressure greater than 5 kg / cm2, smaller than 10 kg / cm2, compaction pressure = 5 + working pressure
c) Working pressure greater than 10 kg / cm2, compaction pressure = 1.5 times the working pressure. Whereas for boilers that have been used, compaction pressure = maximum working pressure + 3 kg / cm2,

6) The pressure on the test pressure is carried out not too long, then after that the pressure is lowered slowly at a maximum speed of 5 kg / cm2 / minute.

k. Steam test (experiment with steam pressure)
This experiment was conducted to determine the work ability of the safety valve adjusted to the purpose of use. By not exceeding the allowable pressure. This experiment is carried out at each:
1) Replacement of each safeguard
2) Use of safety level using a spring.
3) Safety levels that work are doubtful.
4) Replacement of fuel types
5) Each boiler is equipped with an automatic device

CHAPTER IV COVER

A. Conclusion
1. All auxiliary planes that are on board are very important functions, especially boilers which function to produce steam (steam) which is used to run auxiliary machines and other equipment that uses steam (steam) power.
2. To maintain and prevent damage from the boiler, checks must be carried out periodically, to find out how the parts of the boiler work and ensure all other equipment is still feasible to use or must be replaced.
3. Maintenance of boilers which includes checking boiler water regularly to prevent corrosion of pipes and equipment on ships using steam (steam).

B. Suggestions – Suggestions
1. Before running the ship, we should first check everything related to the smooth operation of the ship, especially on the auxiliary aircraft boiler.
2. We recommend that the maintenance of the boiler needs to be done regularly, to avoid more severe damage.
3. Do not underestimate the damage to the boiler part which is one of the important aircraft in the operation of auxiliary engines and mains.
As a machinist, you should be more careful and professional in handling the engines, especially on the ship’s engine, because with perfect maintenance, the engine will always be smooth during operation.

PT INDIRA MITRA BOILER