Boiler Water ChemistryBoiler Water Chemistry

ByByB.A.ChemmannoorB.A.Chemmannoor

STEAGSTEAG--encotecencotec

Nalco Chemical Co.Nalco Chemical Co.

BoilerBoilerPrePre--Treatment

CondensateCondensateReceiverReceiver

ProcessProcess

ProcessProcess

ProcessProcess

Treatment

BlowdownBlowdownflash tank

Flash Flash tank

Low Low pressure pressure steamsteam

flash tank tank

Major ProblemsMajor Problems

Corrosion Corrosion

ScaleScale

SolubilitiesSolubilitiesCompound ppm as CaCO3

32 oF (0 oC) 212 oF (100 oC)CalciumBicarbonate 1620 decomposesCarbonate 15 13Sulfate 1290 1250

MagnesiumBicarbonate 37,100 decomposesCarbonate 101 75Sulfate 170,000 356,000

SodiumBicarbonate 38,700 decomposesCarbonate 61,400 290,000Chloride 225,000 243,000Hydroxide 370,000 970,000Sulfate 33,600 210,000

Scale Formation MechanismsScale Formation Mechanisms

Precipitation of insoluble hardnessPrecipitation of insoluble hardness

Ca(HCOCa(HCO33 ))22 + HEAT + HEAT ------> CaCO> CaCO33 + H+ H22O + COO + CO22

MgMg+2+2 + OH+ OH-- ------>> MgOHMgOH++

HH22SiOSiO33 ------> H> H++ + HSiO+ HSiO33--

MgOHMgOH++ + HSiO+ HSiO33-- ------> MgSiO> MgSiO33 + H+ H22OO

Exceeding saturation through evaporation, resulting Exceeding saturation through evaporation, resulting in crystallizationin crystallization

egeg. CaSO. CaSO44, SiO, SiO22

Found in Boiler DepositsFound in Boiler DepositsName FormulaAcmite Na2O•Fe2O 3•4SiO 2Analcite Na2O•Al2O 3•4SiO 2•2H2OAnhydrite CaSO 4Aragonite CaCO 3 (gamma form)Basic magnesium phosphate Mg3(PO 4)2•Mg(OH)2Brucite Mg(OH)2Calcium hydroxide Ca(OH)2Calcite CaCO 3 (beta form)Copper CuCuprite Cu2OFerrous oxide FeOGoetnite Fe2O 3 • H2O (alpha form)Gypsum CaSO 4•2 H2OHematite Fe2O 3Hydroxyapatite Ca10(PO 4)6(OH)2Magnetite Fe3O 4Serpentine (magnesium silicate) 3MgO•SiO 2•2 H2OSodium ferrous phosphate NaFePO 4Tenorite CuOThenardite Na2SO 4Xonotlite 5 CaO•5 SiO 2 •H2O

SilicaSilica

Forms deposits in boilers Forms deposits in boilers

Occurs as magnesium silicate orOccurs as magnesium silicate or silicicsilicic acidacid

Selective silica carryoverSelective silica carryover

Cannot be controlled mechanically by steam Cannot be controlled mechanically by steam separatorsseparators

Not usually a problem with boilers with less than Not usually a problem with boilers with less than 600 psig pressure600 psig pressure

Selective Silica CarryoverSelective Silica Carryover

Silica is selectively dissolved into Silica is selectively dissolved into the steamthe steamControlled by limiting the silica Controlled by limiting the silica concentration in the boiler waterconcentration in the boiler waterControlled by limiting boiler Controlled by limiting boiler pressurepressureControlled by maintaining high Controlled by maintaining high pHpH

Forms of Iron ScaleForms of Iron Scale

Iron is usually found in a boiler as one or more of the followinIron is usually found in a boiler as one or more of the following:g:

A complex with calciumA complex with calcium

A complex with phosphateA complex with phosphate

Hematite FeHematite Fe22OO33

Magnetite FeMagnetite Fe33OO44

Effect of Scale on Heat TransferEffect of Scale on Heat Transfer

Effect of Scale on Tube TemperatureEffect of Scale on Tube Temperature

Effect of Scale Effect of Scale -- ExampleExample

Effect of Scale Effect of Scale -- ExampleExample

Temp Drop Across Water Film = 76Temp Drop Across Water Film = 76o o F.F. Max. Tube Temp (1004Max. Tube Temp (1004o o F.) is above allowableF.) is above allowableTemp Drop Across Internal Scale = 362Temp Drop Across Internal Scale = 362ooF.F. Oxidation Temp limit of SAOxidation Temp limit of SA--210 Carbon Steel210 Carbon SteelTemp Drop Across Tube Wall = 66Temp Drop Across Tube Wall = 66o o F.F.Assume CaSOAssume CaSO4 4 scale (0.024”)scale (0.024”)Thermal Conductivity = 10 BTU/ftThermal Conductivity = 10 BTU/ft22--hrhr--o o F/inF/in

Scale ProblemsScale Problems

Boiler tube failureBoiler tube failure

Caused by reduced heat transfer and tube Caused by reduced heat transfer and tube overheatingoverheating

UnderUnder--deposit corrosiondeposit corrosion

Caused by high concentration of corrosive Caused by high concentration of corrosive agents (usuallyagents (usually NaOHNaOH))

Scale PreventionScale Prevention

Precipitation of hardness in the boilerPrecipitation of hardness in the boiler

Reduce amount of hardness entering boilerReduce amount of hardness entering boiler

Keep the hardness solubleKeep the hardness soluble

Coagulation TreatmentsCoagulation Treatments

Principles Principles

Calcium hardness is precipitated as Calcium Calcium hardness is precipitated as Calcium CarbonateCarbonate

Magnesium hardness is precipitated as Magnesium hardness is precipitated as Magnesium Hydroxide or Magnesium Magnesium Hydroxide or Magnesium SilicateSilicate

Coagulation Treatment ApplicationsCoagulation Treatment Applications

A Coagulation Program Can Be Used When: A Coagulation Program Can Be Used When:

Boiler pressure < 350 psigBoiler pressure < 350 psig

FeedwaterFeedwater hardness > 60 ppmhardness > 60 ppm

Boiler alkalinity < 500 ppmBoiler alkalinity < 500 ppm

Coagulation TreatmentsCoagulation TreatmentsAdvantageAdvantage

Can treat very highCan treat very high feedwaterfeedwater hardnesshardness

DisadvantagesDisadvantagesLow cyclesLow cycles

High boiler TDSHigh boiler TDS

HighHigh blowdownblowdown -- wastes heatwastes heat

Scale formation Scale formation

Treatment With Makeup SofteningTreatment With Makeup Softening

Requirements for SuccessRequirements for Success

Proper Operation and Maintenance of MakeProper Operation and Maintenance of Make--up Equipmentup Equipment

Chemical Conditioning for Residual HardnessChemical Conditioning for Residual Hardness

Current Treatment TechnologiesCurrent Treatment Technologies

There are three technologies in common use today:There are three technologies in common use today:

Phosphate residualPhosphate residual

ChelantsChelants

AllAll--polymer treatmentpolymer treatment

Phosphate ResidualPhosphate Residual

ChemistryChemistry

Precipitates calcium as calcium phosphatePrecipitates calcium as calcium phosphate

Precipitates magnesium as magnesium hydroxidePrecipitates magnesium as magnesium hydroxide

Phosphate TechnologyPhosphate TechnologyTypes of PhosphatesTypes of Phosphates

Ortho phosphatesOrtho phosphatesMonoMono--,, didi--, tri, tri-- sodium phosphatessodium phosphates

Poly PhosphatesPoly PhosphatesSodiumSodium hexahexa meta phosphate meta phosphate

SodiumSodium heptahepta meta phosphatemeta phosphate

SodiumSodium tripolytripoly phosphate phosphate

Tetra sodiumTetra sodium pyropyro--phosphatephosphate

Phosphate TechnologyPhosphate Technology

FeedpointsFeedpoints

Ortho phosphateOrtho phosphate

Feed to boiler drum directlyFeed to boiler drum directly

Poly phosphatePoly phosphate

Feed toFeed to feedwaterfeedwater lineline

IfIf feedwaterfeedwater hardness is > 3 ppm, feed both to steam drumhardness is > 3 ppm, feed both to steam drum

Phosphate TechnologyPhosphate Technology

Detailed ChemistryDetailed Chemistry

(poly) Na(poly) Na55PP33OO1010 + 4NaOH + 4NaOH --> 3Na> 3Na33POPO44 + 2H+ 2H22O O

((orthoortho) Na) Na22HPOHPO44 ++ NaOH NaOH --> Na> Na33POPO44 + H+ H22O O

3CaCO3CaCO33 + 2Na+ 2Na33POPO44 --> Ca> Ca33(PO(PO44))22 + 3Na+ 3Na22COCO33

3CaSO3CaSO44 + 2Na+ 2Na33POPO44 --> Ca> Ca33(PO(PO44))22 +3Na+3Na22SOSO44

Mg(HCOMg(HCO33))22 + 4NaOH + 4NaOH --> Mg(OH)> Mg(OH)22 + 2Na+ 2Na22COCO3 3 + 2H+ 2H22O O

MgClMgCl22 + 2NaOH + 2NaOH --> Mg(OH)> Mg(OH)22 + 2NaCl + 2NaCl

Phosphate TechnologyPhosphate TechnologyAdvantagesAdvantages

Easy to monitor and controlEasy to monitor and control

Does not require high purity makeupDoes not require high purity makeup

Can be used at high pressureCan be used at high pressure

Well understoodWell understood

Can be FDA and/or USDA approvedCan be FDA and/or USDA approved

Can handleCan handle feedwaterfeedwater hardness fluctuationshardness fluctuations

Residual POResidual PO44 is non corrosiveis non corrosive

Large POLarge PO44 residual residual -- buffer for excursionsbuffer for excursions

Relatively low cost ingredientsRelatively low cost ingredients

Phosphate TechnologyPhosphate TechnologyDisadvantagesDisadvantages

Produces precipitates in boiler waterProduces precipitates in boiler water

Excess alkalinity can produce corrosionExcess alkalinity can produce corrosion

May require moreMay require more blowdownblowdown

If so, more heat lost, more chemical usedIf so, more heat lost, more chemical used

Possibility of scalingPossibility of scaling

Normally used with sludge dispersantNormally used with sludge dispersant

Sludge ConditioningSludge Conditioning

Insoluble Calcium Phosphate and Magnesium Insoluble Calcium Phosphate and Magnesium Hydroxide solids formed (Sludge)Hydroxide solids formed (Sludge)

Particulate Iron Oxide returned in condensateParticulate Iron Oxide returned in condensate

Solids settle on hot boiler surfacesSolids settle on hot boiler surfaces

Heat transfer impaired, tube failure riskHeat transfer impaired, tube failure risk

Types of Sludge ConditionersTypes of Sludge Conditioners

Synthetic polymersSynthetic polymers

TanninsTannins

LigninsLignins

StarchesStarches

Use of Sludge Conditioners Use of Sludge Conditioners

Starch Organic ProductsStarch Organic Products

When Mg:SiOWhen Mg:SiO22 ratio < 2ratio < 2

When oil contaminates the boilerWhen oil contaminates the boiler

In food processing plantsIn food processing plants

Lignin Organic ProductsLignin Organic Products

To condition Calcium Phosphate & Iron OxideTo condition Calcium Phosphate & Iron Oxide

Feed & Control of Sludge ConditionersFeed & Control of Sludge Conditioners

Feed toFeed to feedwaterfeedwater as far ahead of boiler as possible. preferred as far ahead of boiler as possible. preferred addition points are:addition points are:

Deaerator storageDeaerator storage

BoilerBoiler feedwaterfeedwater lineline

Direct to steam drumDirect to steam drum

PhosphatePhosphate--Polymer ProgramsPolymer Programs

Affects Calcium & Magnesium precipitationAffects Calcium & Magnesium precipitation

Same precipitation chemistry as other phosphate Same precipitation chemistry as other phosphate programs but different dosage requirements for sludge programs but different dosage requirements for sludge conditioner & phosphateconditioner & phosphate

Provides cleaner boilers Provides cleaner boilers

Application of PhosphateApplication of Phosphate--Polymer Polymer ProgramsPrograms

FeedwaterFeedwater hardness less than 3 ppmhardness less than 3 ppm

Softeners or naturally low hardnessSofteners or naturally low hardness

PhosphatePhosphate--Polymer ProgramsPolymer Programs

AdvantageAdvantage

Can provide much cleaner boilers than other Can provide much cleaner boilers than other conventional Phosphate programsconventional Phosphate programs

DisadvantageDisadvantage

Requires much stricter control ofRequires much stricter control of feedwaterfeedwaterhardness and chemical programhardness and chemical program

ChelantsChelants

Act on dissolved metal ionsAct on dissolved metal ions

Create very soluble complexesCreate very soluble complexes

Competing ions (POCompeting ions (PO44, SiO, SiO22, OH) reduce effectiveness, OH) reduce effectiveness

CommonCommon ChelantsChelants

EDTAEDTA((EEthylenethylene ddiamine iamine ttetraceticetracetic aacid)cid)

Has 6 metalHas 6 metal complexingcomplexing sites which sites which include nitrogen and oxygen atomsinclude nitrogen and oxygen atoms

NTANTA((NNitrilo itrilo ttriaceticriacetic aacid)cid)

Has 4 metalHas 4 metal complexingcomplexing sitessites

Comparison ofComparison of ChelantsChelants

NTA is more thermally stable NTA is more thermally stable –– 900 psig max. for NTA,900 psig max. for NTA,–– 600 psig max. for EDTA600 psig max. for EDTA

NTA has lower cost than EDTANTA has lower cost than EDTA

EDTAEDTA chelateschelates Magnesium better than NTAMagnesium better than NTA

EDTAEDTA chelateschelates ferrous iron better than NTAferrous iron better than NTA

EDTA has full FDA approvalEDTA has full FDA approval

Application ofApplication of ChelantsChelants

Must be fed continuously toMust be fed continuously to feedwaterfeedwater using a using a stainless steel injection quill & pipingstainless steel injection quill & piping

Oxygen must be absentOxygen must be absent

Residual concentration must be kept below 10 Residual concentration must be kept below 10 ppm as CaCOppm as CaCO33 in boiler water to minimize in boiler water to minimize corrosioncorrosion

Accurate feed control is requiredAccurate feed control is required

ChelantChelant Control RangesControl Ranges

Boiler PressureBoiler Pressure ChelantChelant Residual Residual psigpsig (Bar)(Bar) ppm as CaCOppm as CaCO33

400400 (30)(30) 4 4 -- 88

401 401 -- 600 600 (30 (30 -- 40)40) 3 3 -- 66

601 601 -- 10001000 (40 (40 -- 70)70) 3 3 -- 55

ChelantChelant AdvantagesAdvantages

No precipitates formedNo precipitates formed

Heat transfer surfaces cleanerHeat transfer surfaces cleaner

Less frequent acid cleaningLess frequent acid cleaning

Can sometimes reduceCan sometimes reduce blowdownblowdown

ChelantChelant DisadvantagesDisadvantages

Cost more than phosphatesCost more than phosphates

Require stricter control ofRequire stricter control of feedwaterfeedwater qualityquality

More difficult control testMore difficult control test

Excessive residuals are corrosiveExcessive residuals are corrosive

Competing ions can form depositsCompeting ions can form deposits

AllAll--Organic Polymer ProgramsOrganic Polymer Programs

AllAll--polymer program, polymeric blendpolymer program, polymeric blend

Contains noContains no chelantschelants or phosphates, does not require or phosphates, does not require supplemental dispersants supplemental dispersants

Functions byFunctions by solubilizationsolubilization for Calcium and Magnesium for Calcium and Magnesium and byand by dispersancydispersancy for iron and other particulatesfor iron and other particulates

NonNon--aggressive to boiler metalsaggressive to boiler metals

AllAll--Organic Polymer ProgramsOrganic Polymer Programs

Feed to deaerator storage for boilers at < 600 psig and Feed to deaerator storage for boilers at < 600 psig and using softened waterusing softened water

Use other feed points for high pressure boilers using Use other feed points for high pressure boilers using high purity (e.g. high purity (e.g. demineralizeddemineralized) makeup) makeup

Feed program based on statistical upper control limit Feed program based on statistical upper control limit for hardness and iron, not average valuesfor hardness and iron, not average values

Under dosing (<20% of requirement) can produce Under dosing (<20% of requirement) can produce CalciumCalcium AcrylateAcrylate deposits in boilerdeposits in boiler

AllAll--Organic Polymer ProgramsOrganic Polymer Programs

Non corrosive to boiler internalsNon corrosive to boiler internals

Offers clean boilers Offers clean boilers -- enhanced heat transferenhanced heat transfer

Transports 100% of hardnessTransports 100% of hardness

NonNon--volatile volatile -- safe for turbinessafe for turbines

Can test for boiler hardnessCan test for boiler hardness

Simple product test Simple product test -- easy to test for producteasy to test for product

GoodGood passivatingpassivating programprogram

AllAll--Organic Polymer ProgramsOrganic Polymer Programs

Limited to boiler pressures <1000 psigLimited to boiler pressures <1000 psig

Requires low hardnessRequires low hardness feedwaterfeedwater

Some formulations contribute ammonia to steamSome formulations contribute ammonia to steam

Cannot be used as a cleanCannot be used as a clean--up programup program

Boiler CorrosionBoiler Corrosion

Types of CorrosionTypes of Corrosion

Oxygen corrosionOxygen corrosion

Alkalinity concentrationAlkalinity concentration

Caustic corrosionCaustic corrosion

Acid corrosionAcid corrosion

ChelantChelant corrosioncorrosion

Erosion/CorrosionErosion/Corrosion

Oxygen CorrosionOxygen Corrosion

Can be found throughout the systemCan be found throughout the system

Mechanism same as other oxygen corrosion cellsMechanism same as other oxygen corrosion cells

Corrosion mechanisms affected by:Corrosion mechanisms affected by:

–– Oxygen concentrationOxygen concentration

–– TemperatureTemperature

–– pHpH

Boiler MetalBoiler Metal PassivationPassivation

Reduces general corrosionReduces general corrosion

Forms protective barrier on metalForms protective barrier on metal

Black magnetite film Black magnetite film -- FeFe33OO44

Difficult to quantify resultsDifficult to quantify results

BoilerBoiler PassivationPassivation MechanismsMechanisms

Reaction of Water With Boiler Metal:Reaction of Water With Boiler Metal:

Fe + 2 HFe + 2 H22O O --> Fe(OH)> Fe(OH)22 + H+ H22

3Fe(OH)3Fe(OH)22 --> Fe> Fe33OO4 4 + H+ H2 2 + 2H+ 2H22OO

Rate of Magnetite Formation Is:Rate of Magnetite Formation Is:

Temperature dependentTemperature dependent

Spontaneous above 180Spontaneous above 180 ooCC

Effect of pH on Boiler CorrosionEffect of pH on Boiler Corrosion

Types of Caustic Damage in BoilersTypes of Caustic Damage in Boilers

There are two forms of damage caused by caustic soda There are two forms of damage caused by caustic soda

to high pressure boilers, namely:to high pressure boilers, namely:

Caustic corrosionCaustic corrosion

Caustic embrittlementCaustic embrittlement

Caustic CorrosionCaustic CorrosionUsually found only in high pressure boilersUsually found only in high pressure boilers

Problem usually due to depositsProblem usually due to deposits

Localized in boilerLocalized in boiler

Also called crater attack or caustic gougingAlso called crater attack or caustic gouging

No embrittlement of metalNo embrittlement of metal

Requirements for Caustic CorrosionRequirements for Caustic Corrosion

Two conditions are necessary for caustic corrosion to occur:Two conditions are necessary for caustic corrosion to occur:

The presence of a corrosive material in the boiler water The presence of a corrosive material in the boiler water (caustic soda)(caustic soda)

A mechanism for concentrating this materialA mechanism for concentrating this material

Concentrating MechanismsConcentrating MechanismsThe following conditions can result in dangerously The following conditions can result in dangerously high localized caustic soda concentrationshigh localized caustic soda concentrations

Porous metal oxide depositsPorous metal oxide deposits

Metal oxide depositsMetal oxide deposits

Operation above rated capacityOperation above rated capacity

Excessive rate of load increase Excessive rate of load increase

Excessive localized heat inputExcessive localized heat input

Localized pressure differentialsLocalized pressure differentials

Restrictions in generating tube(s)Restrictions in generating tube(s)

Prevention of Caustic CorrosionPrevention of Caustic Corrosion

Prevention of caustic corrosion is achieved by minimizing Prevention of caustic corrosion is achieved by minimizing or eliminating the presence of ‘free’ caustic soda in the or eliminating the presence of ‘free’ caustic soda in the boiler water.boiler water.

Coordinated phosphate Coordinated phosphate

Congruent sodium phosphate Congruent sodium phosphate

PhosphatePhosphate--low hydroxide (trilow hydroxide (tri--ad)ad)

Equilibrium phosphate controlEquilibrium phosphate control

AllAll--volatile treatmentvolatile treatment

Coordinated PhosphateCoordinated PhosphateControl of pH comes from hydrolysis ofControl of pH comes from hydrolysis of trisodiumtrisodium phosphate in phosphate in waterwater

NaNa33POPO44 + H+ H22O O --> Na> Na22HPOHPO44 ++ NaOHNaOH

Molar ratio of sodium : phosphate is 3 : 1 in waterMolar ratio of sodium : phosphate is 3 : 1 in water

FeedwaterFeedwater contamination usually dictates causticcontamination usually dictates caustic--consuming consuming chemicals, such aschemicals, such as disodiumdisodium andand trisodiumtrisodium phosphatephosphate

Does not ensure absence of caustic under concentrating Does not ensure absence of caustic under concentrating conditionsconditions

Nalco Chemical Co.Nalco Chemical Co.

Coordinated pH/ PhosphateCoordinated pH/ PhosphateControl LimitsControl Limits

Congruent ControlCongruent Control

This program was developed to prevent free caustic in This program was developed to prevent free caustic in boiler water during concentrating conditionsboiler water during concentrating conditions

At sodium:phosphate ratio of 2.85 in boiler water, At sodium:phosphate ratio of 2.85 in boiler water, precipitated solids have same concentrationprecipitated solids have same concentration

Safe range is between ratio 2.3 Safe range is between ratio 2.3 -- 2.62.6

Control is based on pH and POControl is based on pH and PO44 valuesvalues

TriTri--Ad ProgramsAd Programs

Boiler water contains low level of caustic sodaBoiler water contains low level of caustic soda

Also called ‘Also called ‘PRECISION CONTROLPRECISION CONTROL’’

Useful when traces of hardness inUseful when traces of hardness in feedwaterfeedwater

Greater risk of caustic corrosionGreater risk of caustic corrosion

Not for high heat flux boilersNot for high heat flux boilers

Not for pressure greater than 1800 psigNot for pressure greater than 1800 psig

Equilibrium TreatmentEquilibrium TreatmentCoordinated and congruent treatments can be difficult Coordinated and congruent treatments can be difficult to controlto control

Phosphate hideout interferesPhosphate hideout interferes

POPO44 levels kept between 1 levels kept between 1 -- 5 ppm5 ppm

Controlled by pH, OH and POControlled by pH, OH and PO44 in boiler waterin boiler water

Phosphate HideoutPhosphate Hideout

Shows as drop in boiler water phosphate under high loadShows as drop in boiler water phosphate under high load

Under concentrating condition, phosphate precipitates from Under concentrating condition, phosphate precipitates from boiler waterboiler water

Further addition of chemical to compensate can cause increased Further addition of chemical to compensate can cause increased depositiondeposition

Can cause localized corrosionCan cause localized corrosion

Phenomenon reverses when heat load dropsPhenomenon reverses when heat load drops

AllAll--Volatile TreatmentVolatile Treatment

Creates a nonCreates a non--corrosive pH without adding dissolved solidscorrosive pH without adding dissolved solids

Can be used at pressures above 600 psigCan be used at pressures above 600 psig

Useful in boilers with severe phosphate hideoutUseful in boilers with severe phosphate hideout

Has no buffering forHas no buffering for feedwaterfeedwater contaminationcontamination

Useful whenUseful when ultrapureultrapure steam is neededsteam is needed

Caustic EmbrittlementCaustic Embrittlement

Should not be confused with caustic corrosionShould not be confused with caustic corrosion

Embrittlement is a special form of stress corrosion crackingEmbrittlement is a special form of stress corrosion cracking

Three conditions must be presentThree conditions must be present–– Concentrating mechanism presentConcentrating mechanism present–– Metal under high stressMetal under high stress–– Must contain silicaMust contain silica

Inhibited by improved fabrication techniques and by organic Inhibited by improved fabrication techniques and by organic and nitrateand nitrate--based inhibitorsbased inhibitors

Other Causes of Boiler CorrosionOther Causes of Boiler Corrosion

FeedwaterFeedwater acid contaminationacid contamination

Surface condenser leaksSurface condenser leaks

Acid leaks fromAcid leaks from demineralizerdemineralizer

Organic materialsOrganic materials

ChelantChelant corrosioncorrosion