UNCLASSIFIED

AD NUMBER

AD465780

NEW LIMITATION CHANGE

TOApproved for public release, distributionunlimited

FROMDistribution authorized to U.S. Gov't.agencies and their contractors;Administrative/Operational Use; JUN 1965.Other requests shall be referred to NavyMarine Engineering Lab., Annapolis, MD.

AUTHORITY

USMEL ltr, 5 Nov 1955

THIS PAGE IS UNCLASSIFIED

NOTICE: When goverment or other drawings, speci-fications or other data are used for any purposeother than in connection with a definitely relatedgovernment procurement operation, the U. S.Government thereby incurs no responsibility, nor anyobligation vhatsoever; and the fact that the. Govern-aent may have fore=ateal, furnished, or in any waysupplied the said drawings, specifications, or otherdata is not to be regarded by implication or other-vise as in any manner licensing the holder or anyother person or corporation, or conveying any rigbtsor permission to manufacture., use or sell anypatented invention that may in any wvay be relatedthereto.

['(114 OPI. IC.,IA, U!SE ONLY

Evaluation of Lithium Hydroxide for

Alkalinity Control of Boiler WaterSoftened With EDTA Chelating Agent

Assignment 73 120MEL R&D Phase Report 209/65

June 1965

ByE. H. Bolander

E. H. BOLANDER

Approved by:

E. M. HERMachinery Systems Division

FOIk OFFICIAL USE ONLY

Evaluation of Lithium Hydroxide forAlkalinity Control of Boiler WaterSoftened With EDTA Chelating Agent

Assignment 73 120MEL R&D Phase Report 209/65

June 1965

ByE. H. Bolander

E. H. BOLANDER

Approved by:

E. M. HERRMANNMachinery Systems Division

ME*L Report 209/65

Distribution List

BUSI!IPS, Code 210L (2)BUSHIPS, Code 320BUSHIPS, Code 342ABUSIIIPS, Code 651NkL, Chemistry Div. (Attr,: Dr. M. ,. Bloom)DDC (20)NAVBOTLAB (Attn: Mr. S. G(eenberg)Addressee (4)

I~ii

- w

MEL Report 209/65

ABSTRACT

An experimental boiler water treatment for1200 psi boilers, using lithium hydroxide (LiOH) andthe disodium salt of ethylenediaminetetraaceticacid, was evaluated in a series of 30-day studiesin model boilers.

This combination was found preferable tothe present method (low-phosphate control treat-ment) or to a modification of the present methodin which LiOH was substituted for NaOH for pHcontrol (previously reported).

When LiOH and NaOH were used independently,without other additives, LiOH was shown, bymetallographiz examination, to have superiorcorrosion inhibitive properties. When LiOH wascombined with Na2 EDTA and dilute seawater (0.5epm chloride), slight corrosion was detected,but inhibition was superior to that exhibitedby NaOH alone. This work is continuing.

iIm [

IMEL Report 209/65

ADMINISTRATIVE INFORMATION

The work reported herein was performed under MEL Assignment73 120, Sub.-project S-R007 08 08, Task 0613. The project wasauthorized by Bureau of Ships letter Rfl17-08-08, serial 634A-226of 22 May 1963. A proposal for additional work on this projectwas submitted to the Bureau of Ships by MEL letter NP/11330(833)of 26 May 1964.

TECHNDICAL REFE RENCES

1 - Bolander, E. H., "Evaluation of Lithium Hydroxide in 1200PSI Boiler Water Treatment," MEL Ret 73 120J, 31 Mar 1964

2 - Bloom, M. C., Fraser, W. A., and Krufield, M., "Corrosionof Steel in Concentrated Lithium Hydroxide at 316 C,"Corrosior, Vol. 18, 1962, pp. 401t-405t

3 - Welcher, Frank J., The Analytical Uses ci EthylenediamineTetreacetic Acid, D. Van Nostrand Co., 1952

4 - Edwards, J. C., and Rozas, E. A., "Boiler Scale Preventionwith EDTA Chelating Agents," Proceedings of the AmericanPower Conference, Vol. 23, 19-1, P..575

5 - Strub, J. W., "Use of Chelating Agents for ContinuousInternal Treatment of High Pressure Boilers," paper pre-sented at the International Water Conference, EngineersSociety of Western Pennsylvania, 29 Oct 1963

6 - Merriman, W. R., "Continuous Boiler Treatment with EDTA:a Progress Report," paper presented at the InternationalWater Conference, Engineers Society of Western Pennsylvania,30 Sep 1964

7 - Frieole, L. G., "Operating Experience With EDTA in Continu-ous Treatment of 1325 PSI Boilers," paper presented atAmerican Power Conference, 28 Apr 1965

8 - Jacklin, C., "Chelating Agents for Boiler Treatment -Research and Actual Use," paper presented at American PowerConference, 28 Apr 1965

9 - Roosen, J. J., and Levergood, J. V., "Use of a ChelatingAgent for Water Treatment in a High Makeup, 900 PSIG Boiler,"paper presented at American Power Conference, 28 Apr 1965

10 - Ristaino, A. J., "In-Service Cleaning of Boiler Watersides,"MEL R&D Phase RePt 7/64, 28 May 1964

11 - AsTMi Manual on Industrial Water and Industrial Waste Water,2nd ed., Method D 807-52 (Corrosivity Test of IndustrialWater - USBM Embrittlement Detector Method), 1962, pp. 272-279

iv

MEL Report 209/65

TABLE OF CONTENTS

Page

DISTRIBUTION LIST iiABS TRACT ii 1ADMINISTRATIVE INFORM'ATION ivTECHNICAL REFERENC:',S ivINTRODUCTION 1EVALUATION 2

Equipment 2Experimental Procedures

RESULTS .DISCUSSION OF RESULTS 5DISCUSSION AND CONCLUSIONS 8RECOMMENDAT IONS 9FUTURE WORK 9LIST OF FIGURES

Figure 1 - Photograph, Boiler Tubes and EmbrittlementSpecimen After 30-Day Exposure to 1200 PSIBoiler Water Treated With Alkaline Chem-icals Only (NaOH or LiOH to pH 10.8)

Figure 2 - Photograph, Boiler Tubes and EmbrittlementSpecimen After Exposure to 1200 PSI BoilerWater Treated With LiOH and Na2EDTA

Figure 3 - Photomicrograph, Example of Typical SurfaceCondition of Boiler Tube Metal AfterExposure to NaOH Treated Water (Run 1)

Figure 4 - Photomicrograph, Typical Surface Conditionof Boiler Tube Metal After 30-Day Exposureto LiOH Treated Water (Run 2)

Figure 5 - Photomicrograph, Typical Surface Condi4tionof Boiler Tube Metal After 60-Day Exposureto Water Treated With LiOH anid Na 2 EDTA(Run ~

V

MEL Report 209/65

EVALUATION OF LITHIUM HYDROXIDE FOR ALKALINITY CONTROL OFBOILER WATER SOFTENED WITH EDTA CHELATING AGENT

1.0 INTRODUCTION

The use of lithium hydroxide (LiOH) instead of sodiumhydroxide (NaOH) in boiler water has been demonstrated in thisLaboratory' and by the Naval Research Laboratorya to significantlyreduce corrosion of boiler tube metal in contact with the treatedwater. When LiOH was used in place of NaOH for pH control withthe conventional Navy low-phosphate contiol treatment for 1200psi* boilers, however, the advantage of minimized corrosion wasdiminished by the rapid consumption of phosphate treating chem-icals, excessively high pH values, and, most seriously, byextensive deposits of lithium phosphate (Li3P0 4 ) on heat transfersurfaces. Such deposits would cause tube failures due to overheat-ing of the metal.

This report discusses the evaluation of an alternate methodfor softening of boiler water which permits the use of LiOH forpH control. The treatment makes use of an organic chelatingagent instead of the phosphates presently used.

The disodium salt of ethylenediaminetetraacetic acid(Na 2 EDTA) was used as the chelating agent throughout thesestudies. This chemical has been widely used as an analyticalreagents and more recently has been produced commercially forchemical cleaning and water softening purposes. References4 through 9 report its successful use as a softening agent inhigh-pressure, power plant utility boilers. Reference 10 dis-cusses its use in formulations for in-service boiler watersidecleaners. The cost of the chelating agent is considerably higherthan that for the conventional phosphate treatment, but its useis considered economically feasible when resulting elimination

'Superscripts refer to similarly numbered entries in the TechnicalReferences at the beginning of this report.

*Abbreviations used in this text are from the GPO Style Manual,1959, unless otherwise noted.

1

MEL Report 209/65

of periodic chemical cleaning of boilers and reduced outages fromtube failures are taken into account.

A base line for comparison of the corrosivity of the EDTAtreatment was established by operating the test boilers withsolutions of NaOH and LiOH only and observing comparative effectsof metal corrosion.

2.0 EVALUATION

The evaluation was conducted in a series of 30-day tests,using one of the electrically heated model boilers describedpreviously.' Because of the relatively low heat flux (ca 20,000Btu per (sa ft)(hr)) in the model boiler, the chemicals (LiOHand NaOH) 4ere not expected to concentrate in sufficient quan-tities to cause embrittlement of the tube surface. An embrittle-ment detector, designed to concentrate boiler water solids in acrevice, was used to determine the effect of such concentrationson highly stressed mild steel specimens. The relative corrosivityof the boiler water solutions was evaluated by metallographicexamination of the embrittlement detector specimens and boilertubes.

2.1 Equipment.

2.1.1 Model Boiler. The boilers were the Nalco A type in whicha central vertical cylinder serves a combined steam drum, down-comer, and water drum. A V-shaped sidearm loop encloses an elec-trical heating element (providing 6800 Btu per hr) which ishoused in a removable mild steel tube. This tube serves as a20,000 Btu per (sq ft)(hr) steam generator and permits inspectionof waterside heat transfer surfaces after the boiler is drained.

2.1.2 Embrittlement Detector. The embrittlement detectors werethe U. S. Bureau of Mines type described in reference 11. Theseare highly stressed mild steel specimens which are exposed toconcentrated boiler water solids deposited by flashing steamthrough an orifice onto the stressed area. The detectors thusprovide the necessary mechanical conditions for susceptibilityto stress corrosion cracking.

2.1.3 Modifications. In addition to the embrittlement detectorsused to detect corrosion resulting from concentration of boilerwater solids, the heating elements (specimen boiler tubes) were

2

MEL Report 209/65

modified to form inspection sites on which dissolved solids wouldconcentrate preferentially. This was done to demonstrate reactionson metal surfaces resulting from the treatment chemicals. Themodifications were as follows:

a Insertion of removable specimens with underlying voidareas.

* Cutting of a circumferential groove (1/11 inch wide and1/8 inch deep) around the specimen tube.

e Drilling of a series of holes of varying diameters(1/32 to 1/8 inch in 1/32-inch increments) to a depth of 1/8inch axially along the heated surface of the specimen tube.

To provide maximum representation of the heated surface, fourseries of holes and the dovetailed slots for the removablespecimens were located at 900 positions (top, bottov., and sides)around the circumference of the heated tubes. The outsidediameter of the tubes was increased by 1/4 inch from the originaldesign to provide a minimum wall thickness consistent with safetyrequirements (ASME boiler code). Figures 1 and 2 are photo-graphs of the experimental tubes.

Initial attemptp were made to ensure uniform rates of heattransfer from L1* stainless steel resistance heaters through themild steel 9pecimen tubes by use of a liquid metal (molten tin)heat transfer medium in the void between the heater sheath andsides of the specimen tube in contact with the heater describedin paragraph 2.1.1. This proved to be unsatisfactory because ofa high loss of heaters through burnout. These failures werecaused either by hot spots from air voids in the molten tin,or by attack, by the tin, of a soldered seam at the base of theheating elements or by poor wetting of the heater by the tin.These tests were then made without a liquid heat transfer medium,using drilled heater receptacle holes as specified by tie heatermanu f ac tu re r.

2.2 Experimental Procedures. The model boilers were cleanedwith inhibited hydrochloric acid and flushed with distilled water.They were passivated with a sodium nitrite solution, drained,flushed with distilled water again, drained, and dried withnitrogen.

3

MEL Report 209/65

2.2.1 Test Conditions.

Run 1: The embrittlei:nt detector and boiler tube wereexposed to 1200 .sig boiler water containing only NaOH. Suf-ficient alkali was 1 resent to obtain a pH of 10.8. (This valueis within the prescribed range (10.4-11.0) for naval boiler waterin 1200 psi boilers.)

Run 2: Repeat of Run 1 using LiOH instead of NaOH for pHcontrol.

Run 3: Repeat of Run 2 using boiler water containing 0.5equivalents per million (epm) chloride ion (Cl-) added as syntheticseawater. (This was the maximum allowable chloride content forshipboard feedwater.)* This concentration of dilute seawatercontains 6.28 ppm hardness expressed as calcium carbonate andresults from the combined calcium and magnesium content of theseawater. Sufficient disodium EDTA (0.045 gram per liter) wasadded to the water to chelate twice this hardness value. Theexcess chelating agent was used to compensate for possiblepartial decomposition and reaction with metal ion in -the boiler water.

2.2.2 Test Procedure. The boilers were filled to operatinglevels with feedwater containing the treatment chemicals. Thefeedwater, as well as the initial charge of boiler water, wastreated with the chemicals because of the limited capacity ofthe model boilers. This technique prevented extreme dilution ofdissolved chemicals in the boiler water when part of it waswithdrawn (for analysis or blowdown), since treated water wasavailable for replenishment, whereas the treated water wouldnormally be replaced with distilled water. The feedwater wasdeaerated by bubbling nitrogen through the solutions and main-taining a slight pressure of nitrogen on the feed tank at alltimes. A chemical injector, located between the feed pump andthe boiler, provided a means of fortifying weak solutions result-ing from reactions of treatment chemicals which formed insolublecompounds. The electrical resistance heaters were then energizedand the water was heated until the pressure reached 1200 ±50 psig.A minimum steam leak was directed against the stressed specimen in

*Recently reduced to 0.2 epm CI-.

4

MEL Report 209/65

the embrittlement detector. The minimum leak rate was consideredto be reached when a fogged area was observed on a mirrored metalsurface held near the detector orifice. Thereafter, the leak waschecked daily and the leak rate adjusted when necessary.

During each exposure period (30 days), boiler water samples werewithdrawn daily and analyzed for pH and alkalinity. During Run 3(LiOH + EDTA treatment), an additional test was performed dailyfor either hardness or residual (unreacted) EDTA. These additionaltests were made by complexiometric titrations using the azo dyeEriochrome Black T as an indicator. Hardness or EDTA deficiencywas determined by titration of 100-ml samples with standard(0.005 N) EDTA solution (i ml = 5 ppm CaCO3). Residual EDTA wasdetermined bv titration with 0.005 N magnesium sulfate solution(1 ml = 18.6 ppm Na 2 EDTA). The reagents and details are describedin reference 4. On the basis of results of these analyses, eitheradditional chemicals were injected or the boilers were blowndown. To prevent concentration of solutions within the boiler,no steam was removed during the test period.

2.2.3 Inspection. After 30 days of exposure, the boilers weredrained and the boiler tube and embrittlement specimens wereremoved, examined, and photoqraphed. Both boiler tube andembrittlement specimens were sectioned and examined under amicroscope to expose evidence of surface corrosion. Photo-micrographs were made of typical surface oxidation-or subsurfaceattack.

3.0 RESULTS

The test conditions for each run and the results of thevisual examinations of the specimens after each run are summarizadin the following tabulation. (See page 7.)

4.0 DISCUSSION OF RESULTS

Run 1: NaOH Treatment. 30 Days. No difficulties wereencountered in maintaining pH values within the specified range(10.4-11.0). Actual pH values ranged from 10.8 to 11.0. Dailyalkalinity aanalysis showed that the concentration of hydroxylions ranged between 0.4 and 1.5 epm. Other than the withdrawalof analytical samples (approximately 300 nil), no blowdown wasrequired. No injections of NaOH, other than that present in thefeedwater, was required.

5

MEL Report 209/65

Both the embrittlement specimen and the boiler tube were removedfor examination. After 30 days of exposure, the tube was coatedwith a magnetite film and was free from foreign deposits.No cracks were detected in the embrittlement specimen when examinedunder low power magnification (60x). Additional stressing of thespecimen by further bending failed to reveal any cracks that mayhave formed but were too fine to be visible without additionalstressing of the surface. The embrittlement specimen and theboiler tube were sectioned to expose surface films and underlyingmetal. Metallographic examination of these specimens at 250Xshowed significant surface oxidation. Most of the corrosionoccurred in the small diameter holes drilled in the tube walls.Of the several diameter holes used, the largest (1/8-inch diameter)showed the most significant attack. Exhibit "A,ý' Figure 1 showsthe tube and embrittlement specimen from this run. Figure 3shows an a.cea at the base of a hole where severe pitting was noted.

Run 2: LiOH Treatment, 30 Days. Some difficulty wasexperienced in maintaining the pH within the desired range.On the ninth day, the pH reached the maximum allowable limit(11.0) and required boiler blowdown. Daily alkalinity analysisshowed that the hydroxyl ion concentration ranged between 1.3 and1.7 epm. These comparatively high results may have been causedby atmospheric carbon dioxide which had been adsorbed in the LiOHstock solution with which the feedwater was treated. If thiscarbon dioxide were later released in the steaming boiler,increased pH and alkalinity values would result.

Visual examination of the exnbrittlement specimern and boiler tubeshowed no unusual effects. Exhibit "B," Figure 1 shows the tubeand embrittlement specimen after 30 days of exposure from this run.No cracks were found in the embrittlement specimen. Metallographicexamination (250X) of these specimens after sectioning revealed arelatively thin, uniform oxide film with virtually no subsurfaceattack. A representative section is shown in Figure 4.

Run 3: LiOH + Seawater + EDTA, 30 Days. The pH and alka-linity values obtained during this run were somewhat higher thanthose observed in Run 1. Blowdown was required on five occasionswhen pH values exceeded the prescribed maximum limit of 11.0.

6

MEL Report 209/65

Test Results

l Additional BoilorWater Controls

Run Feedwater Required During observations After Exposure

No. Composition Exposure Boiler Tube Embrittlement Specimen

1 Deionized water None. Boiler Visual inspection revealed No cracks detected. Rela-containing enough water pH ranged only a normal biack oxide tively heavy and irregularNaOH to obtain pH from 10.8-11.0. film (Exhibit "A," Figure 1). surface oxidation but notof 10.8. Alkalinity ranged Microscopic examination of as pronounced as that found

from 1.0-1.5 epm. sectioned tube showed rela- in holes in boiler tube.tively severe metal attack(Figure 3) most prevalent onwalls and base of 1/8-inch-

' diameter holes.2 Deionized water Approximately 3I Appearance by visual examina- No cra .ks d~ttected. Some

with LiOH added of boiler capac- tion similar to hun 1 (Ex- uniform surface oxidationto obtain pH of ity discharged to hibit "B," Figure 1). Micro- but considerably less than10.8. waste on 9th day scopic examination revealed that observed for Run 1,

when pH values considerably less surfaceexceeded 11.0. oxidation and no subsurfaceAlkalinity values attack (Figure 4), as notedranged from 1.3- for Run 1.1.9 epx.

3 Deicnized water Boiler blown down Appearance by visual examxna- No cracks detected. hicro-and with synthetic on 5th day to tion revealed exceptionally scopic examination after 60

3A seawater added to reduce excessive clean metal surfaces after days showed slight irregu-obtain chloride pH value (>11.0). 30 days of exposure (Figure lar surface oxidation notedconcentration of Hardness (0.5-1.0 2). Exposure was then con- but considerably less pro-0.5 epm Cl" and ppm CaCOG3 de- tinued for a second 30-day nounced than that seen on6.3 ppm hardness tected on 3rd day period (Run 3A), after which specimen from Run 1.as CaCO3 + 45 pp"n when sufficie.t microscopic examination ofNa2 EDTA + LiOH tos..vaEDTA was in- the sectioned specimen showedobtain pH of -tore slight attack of metal sur-10.8. - . faces but much less extensive

M'. than 30-day results obtainedresidu. in Run 1 (Figure 5). Exami-ranged from 1.0- nation of a sample of the7.0 ppm Na2 EDTA, deposit scraped from the tubeshowing some de- by X-ray diffraction showed

iccposition of ur• lithium ferrite (LiFe 08) toreacted EDTA or be the only identifiable con-reaction with diw stituent.solved corrosionproducts duringthe exposure.

Hardness was detected on three occasions, ranging from 0.5 to 1.0ppm (as CaCO 3). The boiler water was fortified at these times byinjecting sulficient Na2 EDTA to restore the original excess ofthe chelating agent. During the remainder of the run, residualNa2 EDTA ranged from less than 1 to 7 ppm, indicating some decompo-sition of the free EDTA or reaction with dissolved corrosionproducts.

7I

MEL Report -2-09/65

After 30 days of exposure, the specimens were removed and examinedwithout magnification or further stressing of the embrittlementspecimen. All surfaces appeared to be in excellent condition withno apparent corrosion. They were then reinstalled and exposedfor a second 30-day period.

Run 3A: LiOH + Seawater + EDTA, 30 Days. The embrittlementspecimen and heater tube from Run 3 were used for this run. Afresh feedwater solution was prepared with fresh LiOH to precludethe possibility of CO2 being absorbed in the LiOH stock sclution.

Although pH values rose to the prescribed maximum on the thirdday, no blowdown was required during this run to control pH.Except for the 3 days when the pH was 11, other values rangedfrom 10.6 to 10.9, with corresponding alkalinity concentrationsranging from 1.0 to 1.9 epm.

Figure 2 shows the appearance of the heater tube and embrittlementspecimen after the first and second 30-day exposure periods.

Metallographic examination of the specimens sectioned after thesecond 30-day exposure showed metal surface oxidation to beuniform and similar to that found in Run 2. There was someslight subsurface attack, which is attributed to the combineCeffects of longer exposure and possible corrosive attack fromsodium in the dilute seawater or treatment chemicals (di-sodiumEDTA ald sodium salts in seawater). A typical area is shown inFigure 5. The presence of chlorides in the diluted seawater mayalso have been responsible for the slightly more aggressiveaction in this run.

Examination of a sample of the deposit scraped from the surfaceof the boiler tube showed lithium ferrite (LiFe 5 O8 ) to be theonly identifiable constituent.

5.0 DISCUSSION AND CONCLUSIONS

The results of these preliminary tests appear to confirm thehypothesis that the use of EDTA with LiOH would be beneficial intreating naval boiler water by minimizing corrosion and scalingof metal heat transfer surfaces. The problem of insulating depositformation resulting from the use of LiOH with phosphate treatingchemicals is eliminated. FL-ther improvement may be gained byfurther reducing boiler water contamination by maintaining lower

8

MEL Report 209/65

feedwater chloride limits and the use of a more stable chelatingagent or other water softening chemical..

The results of this evaluation demonstrate some signif.cantattributes of the experimental boiler water treatment.

* These results complement those reported by NRL under staticconditions (capsule tests) and show that treatment wi'th LiOHresults in less aggressive metal attack than similar treatmentwith NaOH.

* The con2bined indication of continuous reduction of EDTAabove that required for softening and the excellent appearance ofthe specimen boiler tube after the first 30-day exposure indicatethat some in-service cleaning is accomplished by use of the chelat-ing agent.

* The problem of forming insulating deposits experiencedwith the substitution of LiOH for NaOH in the present Navy low-phosphate treatment, previously reported, is eliminated.

* The existence of slight corrosion with this treatmentwhen exposed to an environment of sea-water contamination showsa necessity for further study in this area. Future tests willinclude experiments in which gross quantities of seawater are addedto the boiler water to simulate shipboard conditions restultingfrom gross condenser leakage or a possible tactical situationwhich would require makeup of condensate return with seawaterrather than evaporator distillate.

6.0 RECOMMENDATIONS

Recommendation of a full-scale trial in a shipboard boilerof the use of LiOH as a water treatment chemical is withheldpending results of current and planned future tests in the Nalcoboilers.

7.0 FUTURE WORK

7.1 Tests are currently under wvay, iusing the Nalco boilers, toassess the use of the tetralithiuom salt of ethylenediamine-tetraacetic acid (LikEDTA) for water softening. LiOH is usedto control the pH. Results will be reported when the work iscompleted.

9

MEL Report 209/65

7.2 The effect of gross amounts of seawater, due to condenserleakage or operational requirements, will be studied in LiOHchelate systems.

7.3 The use of borates for water softening with LiOH for alka-linity control will also be investigated.

7.4 A desk study of the feasibility of using ion exchange resinsfor feedwater treatment has recently been completed. The reportis being prepared.

10

MEL Report 209/65

USNMARINE EN.I EERING LABORATORY

Exhibit "A" Exhibit "B"NaOH, Run 1 LiOH, Run 2

VI

I'

II

Figure 1

Boiler Tubes and Embrittlement Specimen After 30-Day Exposure to1200 PSI Boiler Water Treated With Alkaline Chemicals Only

(NaOH or LiOH to pH 10.8)

MEL Report 209/65

USNMARINE ENGINEERING LABORATORY

Exhibit "C" Exhibit "D"After 30 Days, Run 3 After 60 Days, Run 3B

4 4ý

Figure 2

Boiler Tubes and Embrittlement Specimen After Exposure to1200 PSI Boiler Water Treated With LiOH and Na2 EDTA

MEL Report 209/65

USNMARINE ENGINEERING LABORATORY

OxideFilm

TubeMetal

Figure 3Photomicrograph, Example of Typical Surface Condition of

Boiler Tube Metal (Wall of 1/8-Inch-Diameter Hole)After 30-Day Exposure to NaOH Treated Water (Rur 1) (250X)

MEL Report 209/65

USNMARINE ENGINEERING LABORATORY

SOxideFilim

•-TubeMetal

Figure 4Photomicrogn. aph, Example of Typical Surface Condition of

Boiler Tube Metal (Wall of ]/ 8 -Inch-Diameter Hole)After 30-Day Exposure to LiOH Treated Water (Run 2) (250X)

Secuzity Classification UnclassifiedDOCUMENT CONTROL DATA- R&D

(Socurity cloooilication of title. body of abstract ind indexing annotation muat be entered when tho over.ll tepoH to cLa.tiledo)

I ORIINATIN G ACTIVITY ýCqrpopole..outhoC? 12a REPORT SECURITY CLASSIFICATIONU. S. Navy Marine E:ngineering Laboratory iUn,:lassifiedAnnapolis, Maryland 2zb GROUP

3 REPORT TITLE EviLa.-tion of Lithium Hydroxide for Alkalinity Control of

BoilP3r Water Sortened With EDTA Chelating Agent

4 DESCRIPTIVE NOT

ES (Type of report and inclueive dat,•s)

Phase ReportS AUTHOR(S) (Lost name. firut nano, initial)

Bolander, E. H.

6 REPORT DATE 70 TOTA, NO OF PAGES 7b NO OF REFS

June IQ65 1-5 1 iiSo COPTRACT OR GRANT NO S8 ORIGINATOR'S NEPORT NUMIER(S)

PRoJECTNo S-R007 08 08 MEL 209/65

Task 0613 b

d I Assignment 73 12010 A V A IL ABILITY/LIMITATION NOT!CES

Qualified requesters may obtain copies of this report from DDC.

11 SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY

NAVSHIPS

13 AESTRACT

An experimental boiler water treatment for 1200 psi boilers, usinglithium hydroxide and the disodium salt of ethylenediaminetetra-acetic acid, was evaluated in a series of 30-day studies in modelboilers. This combination was found preferable to the presentmethod (low-phosphate control treatment) or to a modification ofthe present method in which LiOH was substituted for NaOH for pHcontrol (previously reported). When LiOH and NaOH were usedindependently, without other additives, LiOH was shown, by metal-lographic examination, to have superior corrosion inhibitiveproperties. When LiOH was hombined with Na2 EDTA and dilute sea-water (0.5 epm chloride), slight corrosion was detected, butinhibition was superior to that exhibited by NaOH alone. This workis continuing.

(Author)

DD JANG. 1473 UnclassifiedSecurity Cl2ssification

Security C!assification Unclassified .......14 LINK A LINK 3 LINK C

KEY WORDS -WY ftOLA WY OLE W

Boiler waterBoiler scaleWater softenersTreatment chemicals

CNSTRUCTIONS

L ORIGINATING ACTIVITY: Enter the name endifdrmsa imposed by security closslfication, using standard statementsof the contractor, subcont.:actcr, grantee, Departmenat of De- mroh as:

fense activity or other organization (corporate author) isar,• (1) "Qualified requesters may obtain copies of thisthe reportt report frwu DDC.2&. REPORT SECU59TY CLASSIFICATION: Enter the nv_-•. (T "Foreign annitncement and dissemnantion of thisa1! security classification of the report. Indicate whether rtepon by DDC is not authorized.-"Restricted Data" is included. Marking is to be in accord-ance with appropriate security regulations. .3) "U ý Goveinment agencies may obtain copies of

this •,rprt directly fro-, DDC. Othar qualified DDC2b. GROUP: Automatic downgrading is specified in DoD Di- usetrx;all rmquest thr, -hrective 5200. 10 and Armed Forces Industrial Manual Enterthe group number. Also. when applicable, show that optiontl ."markings have been used for Group 3 and Group 4 as author- (4) "U. S. rilltary agencies may obtain copies of this&zed. report directly frogn DD<C Other qualified users

3. REPORT TITLE. Enter the complete report title in all sa-ll -etrevt thoughcapital letters. Titles !n all cases should be unclassified.If a meaningful title cannot be selected without classifica-tion. show title classification in all capitals in parenthesis (5) "All distribution of this report is controlled. Qual-immediately fol'owing the title. ified DDC. uriers shall request through

4. DESCRIPTIVE NOTES: If appropriate, enter the type of --__ _

report. e.g., interim, progress, summary. a-mual, or final. If the report baa been furnished to the Office of TechnicalGive the inclusive dates when a specific reporting period is Services, Dep.-tment of Commerce. for sale to the public. indi-covered. cate this fact and enter the price, if known,

5. AUTHOR(S): Enter the name(s) of author(*) as shown on IL SUPPLEMENTARY NOTES: Use for additional explara-or in the report. Enter last name, first name, middle liltiaL tory notes.If military, show rank and branch of service. The name ofthe principal duthor is an absolute minimum requirement. 12. SPONSORI14G MILITARY AC'TIVITY: Enter thme name of

the departmental project office or laboratory sponsoring (pay'6. REPORT DATL- Enter the date of the report as day, irn for) the research and development. Include address.month. yearn or month, year. If more than one date appear-son the report, use date of publication. 13. ABSTRAC"'. Enter an abstract giving a brief amd factual

summary of the document indicative of the report, even though7a. TOTAL NUMBER OF PAGES: The total pi'ge count it may also appear elsewhere in the body of the technical re-should follow normal paginatio procedures, ie., enter the port. If additional spact is required, a continuation sheet shallnumber of pages containing information, be attached.

7b. NUMBER OF REFERENCES Enter the total number of It is highly desirable that the abstract of classified reportsreferences cited !- the report. be unclassified. Each paragraph of the abstract shall end with

ga. CONTRACT OR GRANT NUMBER. If appropr;ate, eZter an ladicotion of the military e;curity classification of the in-the applicable number of the contract or grant under which formation in the paragraph, represented as (TS). (S). (C). or (U).the report was -mritten. Th=:- is no limitation on the length of the abstract. How-8b. 8, & 8d. PROJECT NUMBER: Enter the appropriate ever, the suggested length is from 150 to 225 words.military depatment identification, such as project number, 14. KEY WORDS: Key words are technically meaningful termssubproj/•ct number, system numbers, task num~ber, etc. s or short phrases that characterize a report and may be used as9a. ORIGINATOR'S REPORT NUMBER(S): Enter the offl- index entries for cstaloging the report. Key words must beciail report number by which the document will be identified selected so that no security classification is required. Identi-and controlled by the originating activity. This number must fiers. such as equipment model designatico, trade name, military

be unique to thIs report. project code name, geographic location, may be used *a key

9b. OTHEn REPORT NUMBER(S): If the report has beeni words b,,%t will be followed by an indication of technical con-assigned any other report numbers (either by the originator text. The assignment of Linkt. riles. and weights is optional.or by the sponsor). also enter this number(s).

10. AVAILABILITY/LIMITATION NOTICES: Enter any li-.itations on further dissemination of the report, other than those,

DD I 1473 (BACK) UnclassifiedSecurity Clamificatioc