DREWPLEX® Boiler Water TreatmentsRevolutionary Protection for Your Vessel’s Steam-Generating System

DREWPLEX AT Boiler Water Treatment. . . the first insurance against the costs of feedwater upsets

DREWPLEX OX Corrosion Inhibitor. . . superior, non-hazardous corrosion control

Technological leadership demands more thansuperior technology. In the marine industry, italso requires an insider’s understanding ofshipboard operations—and the ability torecognize and respond creatively to changingneeds. That powerful combination of resources,expertise and insight has made the Drew MarineDivision of Ashland Specialty Chemical Companythe undisputed leader in water treatmenttechnology for more than half a century.

Maintaining low-pressure exhaust gaseconomizers and auxiliary boilers in goodcondition became vastly easier and moreefficient in 1975 when Drew Marine introducedthe industry’s first one-drum, multi-systemwater treatment. This phosphate-basedprogram proved very effective for preventingheat-reducing scale on boiler steam-generatingsurfaces. And with hydrazine, a powerfuloxygen scavenger, wrapped into the sameformulation, it also reduced system corrosiondramatically. The convenience of all-in-onedosing ensured universal acceptance by motorvessel operators, and with widespreadimitation this program quickly became theindustry standard.

More than 20 years later, one-drumtreatments continue to provide exceptionalperformance under conditions where feedwater quality is good and predictable—they work very well at preserving that quality.

However, the ability to maintain thesecontrolled conditions is becoming increasinglyrare. With heavy demands on limited crew andvessel operation, the modern shipboard realityis that feedwater quality variability and upsetsare common. Inefficient evaporator functiondue to inadequate attention or treatmentcontrol typically causes elevated levels ofhardness ions as a result of brine in the make-up water. And condensate contamination cancome from numerous sources, including in-leakage of seawater at coolers and condensers,and of foreign substances at cargo hold heatingcoils. Conventional one-drum treatmentscannot handle the excess hardness in thefeedwater, and that results in scale and depositformation on heat transfer surfaces.

The picture has also changed for thehydrazine component included in these all-in-one treatments. To satisfy the specifications ofthe leading marine boiler manufacturer, alldissolved oxygen must now be removed fromthe feedwater, and that requires concentrateddosing of the preboiler system with an oxygenscavenger. In addition, the listing of hydrazineas a carcinogen has raised health and safetyissues that limit its suitability for long-term use.

Challenges from a Changing World

An effective program for monitoring andtreating boiler water will keep your entire systemrunning at peak efficiency. It will also help youminimize, or avoid completely, the costs of systemproblems. Both of these results represent gains for the economical operation of your vessel. Themagnitude of those gains can best be appreciatedby considering the costs and consequences of nottreating your system.

Potential problems in untreated boiler systems,or inadequately treated systems, come from manysources:

Scale buildup on boiler tubes results fromdissolved and suspended solids. Hardness ions,primarily calcium and magnesium, in thefeedwater can come from seawater, shore andpotable water systems. Even a small amount will form objectionable scales.

Sludge deposits on the tubes are usuallycaused by partly treated waterborne solids thathave not been removed by system blowdown.

Metal oxide deposits form from corrosionproducts—typically iron from the boiler or steam system in the form of ferric oxides, andcopper—returned from the condensate system.

Corrosion in the system is caused principally by oxygen. Due to practical limitations on theability to remove oxygen thermally andmechanically, through deaeration, there isalways some oxygen in the feedwater. It is alsointroduced by in-leakage of air at low-pressurepoints, such as the suction side of pumps, andthe condensers. Depending on the source ofoxygen, system pressure and temperature, andwater chemistry, the potential for corrosionaffects all system sectors. (See schematic) Thepre-boiler, where relatively low temperaturesintensify the effects of the oxygen, is the mostvulnerable. And areas that are intermittentlywetted, such as the internal surfaces of deckpiping and remote sections of the system, arealso at high risk. In the condensate section ofthe after-boiler, additional corrosion effects canresult from low pH acid attack. The source of the carbonic acid that causes this problem iscarbon dioxide produced by the breakdown of organic matter and organic carbonates andbicarbonates in the feedwater.

The Case for Treating Boiler Water

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Normal Sludge with 8% Iron

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If left untreated, oxygen in thefeedwater can cause severepitting in system tubing,especially in the low-temperature pre-boiler section.

ToTurbo

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SUPERHEATER

EXHAUST GASECONOMIZER

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ChemicalFeed Point Options

Increasing accumulations of sludge deposits in boiler tubesmean larger reductions in heat transfer capacity and boilerefficiency—and scale build-up, shown above, has a comparableeffect. Cleaning or replacing blocked tubes adds direct costs.

Loss of Heat Through Deposit Formation, %

The results of scale buildup and deposits,as well as the pitted metal surfaces caused bycorrosion, are extremely costly. Reducedboiler efficiency is inevitable, along with areduction in heat transfer capacity that candirectly affect vessel services. And failure ofthe tubes means complete loss of services.There are significant labor, parts anddowntime costs for replacement, as well ascleaning fouled tubes and removing scaleaccumulations.

The practice of relying on acid cleaning forperiodic descaling as a substitute forcontrolling the scale with chemical treatmentcarries added costs. Vessels subjected to thismethod experience chronic heat transfer loss,which continues to build until the scale isremoved, as well as unscheduled systemoutages. And hazardous acid-cleaningsolutions require special handling by theoperators and environmentally responsibledisposal procedures.

The sum of these costs is a persuasiveargument for pro-active water treatment. Animportant corollary is: the better thetreatment, the greater the savings. And thatis where the DREWPLEX® AT and OX dual-treatment program makes a difference thathas real value.

The Phenomenon of Polymers: Secret Weapon Against Boiler System Deposits

Synthetic polymer technology is the modernapproach to boiler scale and deposit inhibition.Polymers are simply chains of organic molecules.Their superiority to the natural organiccompounds used in earlier technology comes fromtheir consistent molecular weight andcomposition, thermal stability, and resistance tocarbonizing. Polymers were first introduced toshipboard use over 30 years ago in Drew Marine’sAMEROYAL® evaporator treatments. To appreciatetheir benefits for steam-generating systems, it isuseful to revisit the function of three componentsfrom earlier technology that have been preservedin DREWPLEX AT boiler water treatment.

The role of phosphate is to react with hardnessions in the form of calcium. The formulationutilizes hydroxide alkalinity, which acts on thecalcium phosphate, as well as magnesium, to formfluid, non-adherent sludges. These sludges arethen easily removed from the system by bottomblowdown. In addition, special neutralizingamines in the formulation serve as after-boilercorrosion inhibitors that adjust and control pH byneutralizing acids, such as carbonic acid,throughout the condensate system.

Now we look at what synthetic polymers add tothe picture. In a boiler system, these molecularchains perform several important functions:

Dispersion — Polymers provide highly efficientdispersion of sludge particles, which keeps themmoving freely through the system for easyremoval by blowdown. They help keep the sludgein suspension by adsorbing on the particles.(Adsorption occurs when one substance is held to the surface of another substance as a result of a chemical attraction between the two.Absorption, the more familiar term to many,means that one substance penetrates to the inner structure of another.)

Pre-Boiler

Boiler

After-Boiler

Cascade Tankor

Hotwell

CondensateReturn

Makeup

FEEDPUMP

DREWPLEX OX-BWT Dosing System with Metering Pump (continuous)

DREWPLEX AT-BWT Dosing System with Metering Pump (continuous)

Gravity Feed with Flowmeter – Not the preferred method (continuous)

STEAM TOOTHER

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The NewGeneration ofMarine Water

TreatmentTechnology

Has Arrived!

Oxygen Scavenging — The DEHA attaches to oxygenmolecules to form a non-corrosive compound. The catalyst accelerates the rate of the oxygen-removalreaction, which improves corrosion protection,particularly in the vulnerable pre-boiler section.

Volatility — Introduced as a liquid, DREWPLEX OXtreatment is easily volatilized into a gaseous state. In this state, the excess from feedwater—whatever is leftover from the scavenging mission in the pre-boiler—is carried efficiently through the boiler and out into the condensate system. This characteristicenables DREWPLEX OX corrosion inhibitor to protectthe entire steam-generating and utilization system. It also means that the remedy does not contribute tothe problem because no dissolved solids are produced.

Passivation — This function is important because it is virtually impossible to remove all dissolvedoxygen from the condensate system. Shielding thebase metal by passivation is the primary weapon forprotecting that sector. Our treatment becomes a unique reducing agent—it reduces ferric ions toferrous ions that create a passive oxide film calledmagnetite. This tightly bonded molecular layer acts as an efficient barrier between the corrosivecondensate and the metal.

These powerful combined forces are a substantialbenefit to the boiler system and its operators. Oxygen, and its corrosion threat, are virtually eliminated, andthe amount of corrosion products, typically iron andcopper oxides from the condensate system, enteringthe boiler is dramatically reduced. Major improvementsin reliability, efficiency and service life are assured,along with substantial reductions in maintenance and downtime. Its unique properties also makeDREWPLEX OX corrosion inhibitor very effective for protecting idle boilers during wet lay-up.

Unlike hydrazine, DEHA is not carcinogenic—so itshealth and safety benefits ensure the long-term utilityof DREWPLEX OX corrosion inhibitor. Faster actionbecause of its catalyst and more extensive penetrationof the system because of its greater volatility are“extras” that guarantee an immediate advantage.

A Giant Leap Forward in Oxygen Scavenging Technology

The key ingredient in DREWPLEX OX corrosioninhibitor is DEHA (Diethylhydroxylamine), a volatile,non-carcinogenic, highly effective oxygen scavenger. Its application in the DREWPLEX program is a firstfor marine boilers. The DREWPLEX OX formulation,which also contains a catalyst, attacks corrosion onthree fronts:

Crystal modification — By disrupting the shapes andgrowth patterns of crystals formed by hardness ions,polymers prevent the formation of dense hard scale. The end-product of crystal modification is smallerparticles and soft, fluid, non-adherent materials.

Iron dispersancy — Polymers also prevent the deposit of iron returned to the boiler from corrosion in the condensate system.

Chelation — This is the Big Payoff ! The polymersserve as back-up scale inhibitors that supplement and reinforce the phosphate program. In this criticalrole, they act as a reserve agent for controlling deposits from excess hardness that may find its way into the system. When feedwater upsets orcontaminant in-leakage result in more hardness ions than the available phosphate reserve can handle,the polymers react with the remaining calcium andmagnesium ions to prevent hardness from precipitating and forming scale.

The bottom line is low-cost insurance against thehigh costs of feedwater “surprises.” DREWPLEX ATboiler water treatment provides unsurpassed multi-function performance for controlling scale and deposits. The proof is in the results: clean boilers,minimum downtime, low maintenance costs, and minimum need for acid cleanings.

Without treatment, the crystals formed by hardness ions form dense,hard scale as shown at left. The polymers in DREWPLEX AT boilerwater treatment intervene with this process to produce the softer,non-adherent particles shown at right.

The “secret” ingredients in ourDREWPLEX® treatments are actuallynot so secret. In fact, the advancedcomponents in each were originallydeveloped for shoreside industrialapplications, and have beenthoroughly proven. Drew Marine’sability to adapt these chemical“tools” to the unique needs of themotor vessel shipboard environmentis what gives us the technical edgethat translates to leadership.

Oxygen Scavenging at pH 9, 50 Degrees C100

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Application Convenience and Control

Both products in the DREWPLEX® treatmentprogram are formulated as liquids for easy mixingand feeding. The right dose for your boiler willdepend in part on system capacity. It can varyaccording to the purity and quality of yourcondensate returns, and the quality and amount ofmakeup required by the system. Appropriate on-going system doses are determined by simple dailytesting of key treatment parameters.

DosingDREWPLEX AT boiler water treatment, which is

intended for use only in low-pressure systems(up to 32 kg/cm2, or 450 psig), is fed continuouslyinto the feedwater line using a metering pump.The initial dosage recommendation at start-up isnormally 2.5 to 5 liters per tonne of water in thesystem. The typical daily dose is approximately1.0 liter, and will vary according to the operationaldemands on your system.

For low and medium-pressure systems(up to 60 kg/cm2, or 850 psig) with feedwaterrecirculation, DREWPLEX OX corrosion inhibitoris dosed downstream of the feedwater recirculationofftake. If there is no feedwater recirculation, themost effective feed points are at the feed pumpsuction, or into the condensate return atmosphericdrain tank or hotwell. Continuous dosing isadvised for best results with all oxygen scavengerapplications.

Either the storage section of the deaerator or thefeed pump suction is the preferred location fordosing DREWPLEX OX treatment to high-pressuresystems (60 kg/cm2 or 850 psig and higher).Alternative dosing to the HP/ LP turbine crossoveris possible but requires detailed engineering.

TestingDaily water testing is extremely important for

monitoring the actual performance of thesetreatments in a dynamic operating system. Anyvariations in water quality or chemical levels cansignal the need for mechanical adjustments,treatment modification, or both. Boiler watersamples should be taken from the continuous orsurface blowdown, and feedwater samples as closeas possible to the boiler. To ensure reliability,samples should be collected through a cooler. Thisprocess prevents distortion of test results fromflashing, which concentrates the sample anddrives off volatile materials.

The success of your boiler water treatmentprogram depends as much on reliable test resultsas it does on regular monitoring. With fewercrew members available on most vessels to handlemore tasks, accomplishing both goals can be a tallorder. That is why Drew Marine has also pioneeredadvanced, simplified techniques for testingshipboard water treatments. Our most recentinnovation in testing methodology utilizesampoule technology, which provides numerousbenefits over traditional techniques.

Our self-contained test kits have vacuum-sealed, self-filling ampoules containing pre-measured reagents. No mixing or special handling

of delicate, easily contaminated reagents isrequired. Supplied with easy-to-use equipmentand procedures for adding samples and analyzingthe readings, these kits are designed to ensurefast, accurate test results. There is no operatorexposure to hazardous chemicals, or need forspecial reagent disposal, which provides addedsafety benefits for your crew. And the long shelflife of the reagents means less waste.

These benefits have all been built into theDREWPLEX boiler water treatment program.Ampoule kits are available for testing majorsystem parameters, including:

Oxygen Scavenger Levels — Use theDREWPLEX OX Ampoule Test Kit daily tomeasure chemical levels in the feedwater. Dosingcan then be adjusted to maintain the treatmentconcentration within the specified control range.

Hardness — The Total Hardness Ampoule testsimplifies a weekly check on makeup quality.

Ortho Phosphate — The results obtained fromdaily tests enable you to control the level ofsludge-producing phosphate relative to hardnesslevels in the feedwater.

An additional daily test procedure in theDREWPLEX program is necessary to ensure thatsufficient free hydroxide alkalinity is present tokeep calcium hardness sludges in a fluid, non-adherent form. Readings from this test are alsoused to help control hydroxide alkalinity in orderto prevent low pH corrosion. Other procedures areprovided for measuring boiler waterconductivity and condensate pH.

The final proof of technological progress is theability to make life easier—and this unique watertreatment program delivers unsurpassed simplicityfor your daily operation along with completesystem protection. That is the ultimate benefit ofspecialized technical knowledge applied withdecades of practical know-how. With appropriatetraining for operators, the full benefit from theDREWPLEX dual-treatment program can beachieved for your vessel with a daily testing anddosing routine that can be completed in less thantwenty minutes.

Advanced Technologyfor Modern Realities

Drew Marine has responded to thesechallenges with technological advancesthat are certain to set new standards forthe next era in marine low-pressure boilerwater treatment. Our DREWPLEX®

solution is a unique dual-treatmentprogram with proven value for increasingthe efficiency and life of the entire steam-generating system. It also provides theultimate combination of simplicity,flexibility and control.

The “AT” in our new DREWPLEX ATboiler water treatment means “advancedtechnology” that builds and improves on our past successes. DREWPLEX AT is phosphate-based, with all the beneficial, non-hazardous components of its predecessor. The big PLUS is a blend of synthetic polymers, whichcontributes first to enhanced depositcontrol. In a major breakthrough formarine boilers, it also provides a reservefor feedwater upsets. This reserve assures a cleaner boiler even with typical variations in feedwater quality.

We have teamed this powerfultreatment with a non-toxic, non-carcinogenic alternative to hydrazine.Designed for use with low-pressureboilers, DREWPLEX OX corrosioninhibitor is suitable for medium and high-pressure steam-generating systemsas well. And the best news is that the new treatment is better than hydrazine.It functions in the same manner, reacting with oxygen and creating a passive oxidecorrosion barrier on all metal surfacesthroughout the steam-generating system.Yet it reacts more quickly at lowertemperatures, and reaches the moredistant sections of the boiler andconnected piping systems. In addition tothe advantage of independent corrosioncontrol, DREWPLEX OX corrosioninhibitor’s separate formulation allows for complete flexibility in dosing andcontrol techniques, as well as locations.

The benefits of the combinedDREWPLEX treatments add up tounprecedented peace of mind for shipoperators and owners. Used properly, this revolutionary program eliminatesboiler scale deposit buildup and metalloss—and minimizes system-wide steam,condensate and feedwater circuit corrosion from oxygen and low pH attack.That means you can count on trouble-free operation of your steam system and reliable availability of the services itsupports. To help you achieve the fullestbenefits, the DREWPLEX program alsoincludes testing and dosing proceduresdesigned for simple, safe, accurate use.And it is completely compatible with both manual and automated watertreatment systems.

The practical impact of properly applied DREWPLEX treatments isvisible with every boiler inspection. Heat transfer surfaces are free of scale and sludge deposits, in spite of the inevitable variations infeedwater quality, and show no signs of corrosion from oxygen or low pH attack.

One Drew Plaza, Boonton, NJ 07005 U.S.A.Phone: (973) 263-7600 FAX: (973) 263-4491/7463 E-mail: drewmarine@ashland.comWeb Site: www.drew-marine.com

All statements, information and data presented herein are believed to be accurate andreliable but are not to be taken as a guarantee, express warranty or implied warranty ofmerchantability or fitness for a particular purpose, or representation, express or implied, forwhich seller assumes legal responsibility, and they are offered solely for your consideration,investigation and verification. Statements or suggestions concerning possible use of thisproduct are made without representation or warranty that any such use if free of patentinfringement and are not recommendations to infringe on any patent.

©2003 Ashland Inc. All Rights Reserved. ® Registered trademark of Ashland Inc.* Registered service mark of the Chemical Manufacturers Association in the U.S.

and the Canadian Chemical Manufacturers Association in CanadaPrinted in U.S.A.

BW-SB-1(6/03)

BRAZILAshland Brasil Ltda.Av. Paris, 676Bonsucesso 21041-020Rio de Janeiro-RJ, BrazilTelephone: (55-21) 560-3330FAX: (55-21) 560-1538

INDIAAshland Specialty Chemical CompanyDrew Marine 209, Nirman Kendra, No.3 Dr.E. Moses Rd.Mahalaxmi, Mumbai 400011, IndiaTelephone: (91-22) 4910384FAX: (91-22) 4910386

GERMANYDrew Ameroid Deutschland GmbHStenzelring 8D-21107 Hamburg, GermanyTelephone: (49-40) 7524650FAX: (49-40) 75246512

GREECEAshland Hellas Limited14, Skouze Street18536 Piraeus, GreeceTelephone: (30-2) 104288056FAX: (30-2) 104183494

HONG KONGDrew Ameroid (Singapore) Pte. Ltd.Hong Kong Branch25th Floor, Aon Insurance TowerNo. 3, Lockhart RoadWanchai, Hong KongTelephone: (852) 25202010FAX: (852) 28656472

ITALYAshland Italia S.p.A.Drew Marine Via XXV Aprile 14/1116123 Genoa, ItalyTelephone: (39-010) 2461532FAX: (39-010) 2461733

JAPANAshland Japan Co., Ltd.Minato-Ise Building 6F12-1, 3-Chome, Kaigan-DoriNaka-Ku, Yokohama 231, JapanTelephone: (81-45) 2124741FAX: (81-45) 2124754

KOREADrew Ameroid (Singapore) Pte. Ltd.Korea BranchRoom 702, Plaza Building80-5, 4-Ka, Jungang-DongJung-Ku, Busan, KoreaTelephone: (82-51) 4622181FAX: (82-51) 4629854

NETHERLANDSAshland Nederland B.V.Drew Marine Edisonweg 123208 KB Spijkenisse, NetherlandsTelephone: (31-181) 610774FAX: (31-181) 650906

NORWAYAshland Norge A/SFr. Nansens Plass 60160 Oslo, NorwayTelephone: (47) 23310370FAX: (47) 22425288

SINGAPOREDrew Ameroid (Singapore) Pte. Ltd.27 Tanjong PenjuruJurong, Singapore 609025Telephone: (65) 62616544/9FAX: (65) 62650959

TAIWANDrew Ameroid (Singapore) Pte. Ltd.Taiwan BranchRoom 814, Hung Tai Sung Kiang Bldg.No. 152 Sung Kiang RoadTaipei, TaiwanTelephone: (886-2) 2565-3010FAX: (886-2) 2565-3013

UNITED KINGDOMAshland UK LimitedDrew Marine 110 Jermyn StreetLondon SW1Y 6EE, U.K.Telephone: (44-207) 930-1130FAX: (44-207) 839-0348

For additional information contact:

A Responsible Care*

Company

Drew Marine

The Added Valueof Drew Marine

Drew Marine specializes in technologies and services that can help our customersachieve their objectives and be successful intheir businesses. You can count on us for thesolutions and expertise you need. We arerecognized and respected for maintaining the highest standards of quality. In addition,our experience in actively helping customerssolve their problems has earned us areputation for outstanding technical servicethat is unmatched in our industry. Over 3,500 customers operating more than12,000 vessels attest to the superiorperformance provided by our integrated global organization, which features:

• Worldwide distribution and support networkwith 100 supply locations, serving over 900 ports in 48 countries.

• Efficient global communications networkutilizing advanced technology for promptresponse to all customer needs.

• Commitment to the principles of ResponsibleCare*, an initiative of the U.S. ChemicalManufacturers Association for safeguardingboth the environment, and health and safetyin the workplaces and communities we serve.

• Technological leadership with superiorcustomer needs-focused research and development

• Highly trained port service engineers andaccount specialists

• Dependable delivery

• Worldwide governmental and industryapprovals

Ashland Specialty Chemical Company, a divisionof Ashland Inc., is a leading, worldwide supplierof specialty chemicals serving industries includingadhesives, automotive, composites, foundry, merchant marine, paint, paper, plastics, semi-conductor, watercraft and water treatment.Ashland Inc. (NYSE:ASH) is a Fortune 500company providing products, services, andcustomer solutions throughout the world. Ourbusinesses include road construction, specialtychemicals, lubricants, car-care products, chemicaland plastics distribution and transportation fuels.Find us at www.ashland.com.

For confidence in boiler water qualityguaranteed to promote peak efficiency in yoursteam-generating system, the DREWPLEX®

dual-treatment program is the answer. Turn to Drew Marine for that extra measure of expertise and service that makes us the “Added Value” company.

Ashland Specialty Chemical CompanyDivision of Ashland Inc.

Drew Ameroid (Singapore) Pte. Ltd.Shanghai Representative OfficeRoom 209, Union Building100 Yan An East RoadShanghai 200002, ChinaTelephone: (86-21) 6326-9708FAX: (86-21) 6373-3987

CHINA

UNITED STATESAshland Specialty Chemical CompanyDrew MarineOne Drew PlazaBoonton, NJ 07005 USATelephone: (973) 263-7600FAX: (973) 263-7463/4491