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DOCUMENT TITLE

CHEMICAL CLEANING PROCEDURE FOR BOIL

OUT BOILER HRSG 25 TON/HOUR

REVISION No : MHN-00UNIT ISSUING

R&D DEPT.

APPROVED BY :

CHEM. DIV. MGR

DATE :

08 10 - 2007

PAGE :

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I. OUT LINE

1. GENERAL

The internal surfaces of the economizer and steam generatingsections (hereafter referred to as the boiler) should be cleaned to

remove dirt, oil, grease and protective coatings.

The company does not require acid cleaning of the unit as aninitial clean out of the unit. This initial clean out of the unit is tobe accomplished by means of a degreasing flush.

Since commercial degreasing formulations and concentrations. Atambient temperature, approximately 25C (77F), the suggesteddegreasing concentration in the flush water is 0.6% by volume(6 liters of liquid degreasing per 1000 liters of flushing solution).

For cleaning solutions heated to above 65C (150F), thesuggested degreasing concentration in the flush water is 0.5%by volume. Higher (or lower) concentrations may be used,depending on the type of degreasing considered, plant-specificdesign conditions and vendor recommendations.

2. SCOPE OF SUPPLY

No. Description PT.AWMC PT.. Remarks

1. Chemical Magna 106(Emulsion Degreaser) &Magna - 700 (PassivatingAgent)

X

2. Circulation Pump X

3. Chemical Circulation Drum X

4. High Pressure Cleaner Pump X

6. Tool Kits X

7. Personal Safety Equipment X

8. Scaffolding X If needed9. Ladder X

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11. Electric Power Supply X

12. Soft Water Supply X

13. Steam (Hot Water) X

14. Lighting X

15. Temporary Piping/Horse and

Valve

X

16. Disposal Area(Waste Handling)

X

17. Chemical Engineer X

18. Site Office Temporary X

Scope of Works

No. Description PT.

AWMC

PT.

.

Remarks

1. Cleaning & Flushing PipeLine with oil system

X

2. Chemical Transfer to PipeSystem

X

3. Equipment CleaningPreparation

X X

4. Temporary Pipe/Horseconnection to Pipe System X X

5. Preparation of Pipe Systembefore Circulation.

(Isolation of Valves, LevelGauge, Instrumentation Line,Level Control Open / Closethe Pipe Line System)

X X

6. Mechanical & ElectricalWorks (Flank, Packing,Electric power on site and orWelding for CirculationProcess)

X X

7. Project Engineer X

8. Waste Water Treatment(Disposal Area & DemobWaste to Disposal Area)

X

II. SOP

1. DEGREASING/FLUSHING PROCESS

a. Preparation work.b. Install all the hoses and circulating pump needed to water supply

valve, boiler, and chemical tank.

c. Open the boiler manhole on the top of the boiler.

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d. Fill the boiler with demineralized water until boiler operating waterlevel.

e. Heat the water in the boiler up to 60 70C (Steam/hot water byNestle).

f. Circulating the water for 45 minutes and maintain the water

temperature at 60 70C during the circulating period.g. Shut off boiler and drain the water from the boiler system.h. Refill the boiler with demineralized water until boiler operating

water level.i. Heat the water in the boiler up to 60 70C.j. Inject 10-20% Magna 106 (Emulsion Degreaser) needed gradually

into the boilers manhole, and maintain the water temperature at60 70C.

k. Check the boiler: the water pH, TDS/Conductivity, Calcium (TotalHardness), Silica, Iron, Grease Content and water clearness by

visual inspection.l. For every next 30 minutes check the water pH, TDS/Conductivity,

Calcium (Total Hardness), Silica, Iron, Grease Content and waterclearness by visual inspection.

m.Boiler retubing degreasing process usually will last at 6 8 hours. Itwould depend on the oil film in the tubing.

n. When the degreasing process ended, drain all the water from boiler.o. Flush the boiler with demineralized water, until the drained water

from blowdown lineclean.p. Check the pH of the water taken from the demineralized water

supply valve and the pH of the water taken from blowdown line. Itshould be same.

q. Until this step the degreasing process could be ended.

Note :

Degreasing/Flushing Process just remove grease/oil content,dirt and light corrosion from carbon/stainless steel pipesystem. Its not remove Hard Scale (Carbonate/Silica Scale &Hard Corrosion from Carbon Steel pipe. So, Visual inspection

from Degreasing Process is not change surface metal and its notmake Carbon Steel clean (Natural carbon steel color beforescale & corrosion).

For make Carbon Steel clean (Natural carbon steel color beforescale & corrosion) we need one process again afterDegreasing/Flushing. That process isAcid Cleaning or PicklingProcess.

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2. PASSIVATING PROCESS

a. Inject 2-5% of Magna 700 (Passivating Agent) as passivatingagent needed into boiler via manhole.

b. Check the pH, TDS and Nitrite concentration in the boiler water.c. Heat the water up to 60 70C, and maintain the temperature

during the circulation period.d. Monitor the pH, TDS and Nitrite concentration in the boiler water

on a 30 minutes basis.e. After 1 hour, inject the remaining passivating (Magna 700) into

the boiler via manhole.f. Check the pH, TDS and Nitrite concentration in the boiler water.g. Monitor the pH, TDS and Nitrite concentration in the boiler water

on a 30 minutes basis.h. Circulate continously for about 2 hours.i. Once the duration of circulation indicates the completion of the

passivating process, drain the boiler water, and flushed the boilerwith demineralized water.

j. Fill the boiler with demineralized water up to boiler wateroperating level.

k. Inject the water treatment chemicals needed to prevent the futurescalling and corrosion.

Note :

Passivating Process is needed for carbon steel after cleaning to

protective carbon steel for corrosion process later. Oxygen andwater content in piping are main substance caused corrosion.

Passivating Agent can give protection by forming light filming oncarbon steel metal and inhibit oxygen and water contact withmetal.

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