,-------------------------------------- ----- --NAVAL FACILITIES ENGINEERING SERVICE CENTER Port Hueneme, California 93043-4328 TECHNOLOGY FOR CONDENSATE RETURN LINES by John Kunsemiller November1995 TechnicalReport TR-2047-E&U G Sponsored by Chief of Naval Operations Energy Plans and Policy Branch Washington,DC20350-2000 19960123047 Approved forpublic release;distribution unlimited. REPORT DOCUMENTATION PAGE FonnApproved OMB No.0704-018 Publicreportingburdenfor thiscollectionofinformationisestimatedtoaverage1hourperresponse,includingthe timeforreviewinginstructions, searchingexistingdatasources,gatheringandmaintainingthedataneeded,andcompletingandreviewingthecollectionofinformation.Send commentsregardingthisburdenestimateoranyotheraspectof thiscollectioninformation,includingsuggestionsforreducingthisburden,to WashingtonHeadquartersServices,DirectorateforInformationandReports,1215JeffersonDavisHighway,Suite1204,Arlington,VA22202-4302,andto the OfficeofManagementandBudget,PaperworkReductionProject(0704-0188),Washington,DC20503. 1.AGENCYUSEONLY(Leaveblank)2.REPORTDATE3.REPORTTYPE ANDDATESCOVERED November1995 Final;Jan1995through Apr1995 4.TITLEAND SUBTITLE5.FUNDINGNUMBERS TECHNOLOGY FORCONDENSATE RETURN LINES 6.AUTHORIS) JohnKunsemiller 7. PERFORMINGORGANIZATIONNAME(S) AND ADDRESSE(S)8. PERFORMINGORGANIZATIONREPORT NUMBER NavalFacilitiesEngineeringServiceCenter TR-2047-E&U 560CenterDrive PortHueneme,CA93043-4328 9. SPONSORING/MONITORINGAGENCYNAME(S) AND ADDRESSES10.SPONSORING/MONITORING AGENCYREPORT NUMBER Chief of NavalOperations EnergyPlansandPolicyBranch(N420) Washington,DC20350-2000 11.SUPPLEMENTARYNOTES 12a.DISTRIBUTION/AVAILABILITY STATEMENT12b.DISTRIBUTIONCODE Approved for public release;distribution unlimited. 13.ABSTRACT (Maximum200 words) An investigation was conducted by the Naval Facilities Engineering Service Center (NFESC) to deter-minecurrentandemergingtechnologyforcost-effective,durablematerialsforcondensatereturnlines associated with district piping systems for central steam distribution on Navy shore facilities.The distrib-uted steammay beused forbuilding heating,cooking,shipssupply,andother direct-use processes.This investigation sought to identify materials and specific technology to improve the reliability and maintainabil-ity of these condensate return lines.The investigation included literature searches for technology associated with all typesof pipingmaterialsincluding piping materialand piping processes not generally associated withsteamcondensatereturn.Thesearchforadurablematerialtoreplaceexistingmaterialsusedfor condensate return piping was unsuccessful.Provided that returning condensate to the boiler is economical based on site factors,improvements to the reliability and maintainability of condensate return lines can be accomplishedthroughstricter adherencetoexistinginstallationspecificationsandoperatingprocedures. Alternatively,the reliability and maintainability of asteamsystem may be improved by converting allor part of the heating load over to a hydronic system.The economics of this conversion would likely pay only for those facilities considering system replacement or system expansion. 14.SUBJECT TERMS Undergrounddistributionpiping,condensatereturn 17.SECURITY CLASSIFICATION18. SECURITY CLASSIFICATION19. SECURITY CLASSIFICATION OF REPORTOFTHISPAGEOF ABSTRACT UnclassifiedUnclassifiedUnclassified NSN 7540-01280-5500 15.NUMBER OF PAGES 35 16.PRICECODE UL StandardForm298(Rev.2-89) Prescribedby ANSIStd.239-18 CONTENTS Page INTRODUCTION ..............................................................................................................1 BACKGROUND................................................................................................................1 FINDINGS..........................................................................................................................2 Site Classification......... .. . .. ... . .. .. .. ... ..... . .. .. ....... .. ... . . .. .. ... ..... .. ... .. .. . .. . ..... . ... ... .. ... ... ..3 DOD Approved Vendors.......................................................................................3 Current Practice. .. ... ... ... ............. ..... .. .. . . .. .. ..... .. ... .. . . .. .. .. ...... .. . ... ... . .. . ..... ... . .. .. ... . ... ..4 Plastic Piping. . ... .. ...... ....... ...... .. .. . .. ..... . ... ... .... ... . ... . . ... ...... .. . .. .... .. . . .. .. ..... .. ..... ... . .. ...6 Boiler Water Treatment.........................................................................................7 Economics.............................................................. .................. ..............................7 Replacement Pipe Options.. .. . .. . .. ... .... .. .. .. .. ... ... . . ... .... . ... ..... . ... . .. .. .. . . ....... .. ... .. ... . .. .. .8 Repair Options.. .. .. ....... .. .. . .. ..... .. .. ........ .. .. ....... ... .. .. . .. . ... ..... .. .. .. . .. .. . .. .. ... ...... .. ... . .. . ..8 Conversion to Hydronic Heating Systems........... ..................................................10 CONCLUSIONS.................................................................................................................10 RECOMMENDATIONS...................................................................................................12 REFERENCES..................................................................................................................12 BIBLIOGRAPHY..............................................................................................................14 APPENDIXES A- Literature Search Results................................................................................A-1 B- UHDSCommittee Topic List.........................................................................B-1 C- Condensate Return Piping Design. ........ ....... .. .... ... ..... ... .... ... . .. .. ......... .. . ....... ..C-1 D- Energy Loss Calculations for Example.. .. .... . . . .. .. .. ..... ... . .... .. . .... ... .. ... .... ...... .. .D-1 AccesionFor --NTISCRJ\&1 ,g OTICTAB Unannouttced D Justification _________ .., __________________ ,. ___1-----------By----- Distribution I --AvailabilityCodes --- Availand I or Dist Special f.J-1 v INTRODUCTION AninvestigationwasconductedbytheNavalFacilitiesEngineeringServiceCenter (NFESC)todeterminecurrent and emerging technology forcost-effective,durable materials for condensatereturnlinesassociatedwithdistrict pipingsystemsforcentralsteamdistributionon Navyshorefacilities.Thedistributedsteammaybeusedforbuildingheating,cooking,ships supply,and other direct-use processes.Thisinvestigation sought toidentifyspecific technology to improve the reliability and maintainability of the condensate return lines. Upongivingupitslatentheatcontent,steamcondensestowaterandthecondensateis availableforreturntotheboilerviathecondensatereturnpiping.AtmanyNavyactivities, condensateisnotreturnedtotheboilerbecauseitiseithernonrecoverableprocesssteamor because returning the condensate would be a cost penalty.An example of the latter is when strict cleansteam requirementsforshipuseatport dictatediscardingcondensate fromother terminal unitsthatdonotmeetcondensatequalitystandards.Wherecondensatereturnisviable, contaminationandlossof thecondensatearetheengineeringissuestowhich thisinvestigation sought solutions. Theinvestigationincluded literaturesearchesfortechnologyassociatedwithalltypesof pipingmaterialsincludingpipingmaterialsandpipingprocessesnotgenerallyassociatedwith steam condensatereturn.Personalcontactsweremade with individualsrangingfromoperators topipingmanufacturers.Commentsfrommembersof theDepartmentof Defense(DOD) CommitteeonHeatandCoolingExteriorDistributionSystemshadastronginfluenceonthe fmdings. In theabsenceof newtechnologyapplicabletoimprovingthedurabilityof condensate return line piping and based on recommendations totransition away fromcentralsteam heating, thisinvestigation wasexpanded tobrieflyreview theissueassociated with retrofittingsteam to hydronic heating (and cooling) systems. BACKGROUND TheNavyisactivelylookingtoreduceoperatingcostsatshorefacilitiestomeet diminishingoperatingbudgets.Apartof thecostreductionismandated by theEnergyPolicy Act of 1992dealing with theconservation andefficientuseof energy.In the Act,Section152 addressestheFederalEnergyManagementProgram(FEMP)andrequires,bytheyear2005, installation of allenergyandwater conservation measureswith payback periodsof 10yearsin Federalbuildingstothemaximumextentpracticable(Ref1).Conservationof boilerwater through effective condensate return can contribute to meeting this energy objective. Stearnheatingsystemsaredividedandclassifiedaslowpressureorhigh pressure.The lowpressuresteamsystemisonewithaboileroperatingpressurelessthan15psig.High pressure steam is defined as any system with pressures above15psig. A steam distribution piping system can beeither a single pipe design or a two pipe design. Thesinglepipesystem,asthenameimplies,hasonepipethatcarriesbothsupplysteamand 1 returncondensatebetweentheboilerandtheload.Thecounterflowwithinthepipeis accommodated by sloping the pipe to provide gravity return of the condensate totheboiler.The simplicityof thedesignlendsitself toapplicationinsmallbuildings.However,fordistrict heating (single boiler plant with multiple outlying buildings) a twopipesteam heating system is required. The two pipe steam heating system has a supply pipe to deliver the steam and a return pipe tocarry condensate back to the boiler from each terminal unit.The return piping in the two pipe design can be either gravity return or pumped return.As mentioned before,in those cases where condensateisnot available or noteconomicalfor return,the return pipeis typically omitted and condensate is dumped to the sewer. The areseveral acceptable practices forinstallation of district heat piping.System piping can be installed in tunnels, in shallow concrete trenches,in deepburied trenches, in direct buried trenches, or aboveground.Obviously, aboveground installation may not be pretty tolook at,but itserves thepurposeof reducinginstallation and maintenancecosts.Installation guidelinesare availablefromseveralsources,includingMilitaryHandbooks,NavalFacilityEngineering CommandGuideSpecifications,andcommercially,fromsourcessuch astheAmericanSociety of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE). In order to preserve the insulation used on the steam carrier pipe and the condensate carrier pipe,theinsulatedcarrierpipeisprotectedinsideaconduitpipe.Insomecases,theconduit housesasinglecarrier pipewhilein othercases,twocarrier pipescanbeprotected in asingle conduit.TheASHRAESystemsandEquipmentHandbookissuggestedasareferenceon possible arrangement for conduit systems (Ref 2). FINDINGS Theinvestigationprocesssurveyedandreviewedof avarietyof informationsourcesto determinecurrentandemergingtechnologyforcost-effective,durablematerialsforcondensate return lines.The sources of information included: 1.Participants and documentation from recent DOD condensate return line projects. 2.Personnelinvolvedwithdistrictheatingandcondensatereturnprojectsincluding PublicWorksCenters(PWC)andEngineeringFieldDivisions(EFD)utilitiespersonnelat selected Navy bases. 3.Personnel in RDT &E groups at companies identified as having possible technological advances. 4.Sales literature. 5.Technicalpublications(alistingof titlesreviewedduringtheliteraturesearchis included in Appendix A). 2 ------------------------------------Nositesurveyor testingwasperformedinconjunctionwiththisinvestigation.Utility personnelandundergrounddistrictheatingengineerswerereliedonfortheirfieldexperience. Thisinvestigationfocusedprimarilyonreplacementpipingandpipingrepairtechniquesasa meanstoextendservicelifetherebyreducingcondensateloss,andtoreducemaintenance requirements thereby minimizing condensate contamination.For screening durable materials for condensate return piping, a 250F live steam exposure condition was used in this investigation as a minimum criteria. Site Classification For purposes of underground installation, restrictions on conduit system type are classified bytheundergroundwaterconditionsattheprojectsite.ClassesA,B,C,orDcorrespond to underground water conditions ranging from severe to mild, respectively, as described in Table1. ThesiteconditionsdescribedinTable1 forundergrounddistributionsystemshavea significant effect on the function and efficiency of the distribution piping.Class Aand Class B site conditions deservespecialattention because of the possibility of conductive heat lossesand pipingsystemdamagecausedbywetinsulation.Severesiteconditionsmaynecessitate abovegroundinstallation.Thoughabovegroundinstallationsarenotuncommon,theyarenot favored because aboveground distribution piping is unsightly. Site Classification Class A (Severe) f---...:. Class B (Bad) 1----Class C (Moderate) f--__;,-Class D (Mild) L----Table 1 Site Classification Water TableSurface Water Frequently above the bottom of theExpected to accumulate or remain in system.the surrounding soil for long periods. Occasionally above the bottom of the system. Never above the bottom of the system. Never above the bottom of the system. Expected to accumulate or remain in the surrounding soil for short periods. Expected to accumulate or remain in the surrounding soil for short periods. Not expected to accumulate or remain in the surrounding soil. DOD Approved Vendors The Naval Facilities Engineering Command Guide Specification (NFGS)02694Fon the ExteriorUndergroundHeatDistributionSystem(Ref3)coversrequirementsforcontractor designingandprovidingexteriorburiedfactory-prefabricatedpreinsulatedsteampipingand condensatepipingforClassAandClassBgroundwaterconditions.Installationof newor 3 modification toexisting steam distribution piping at Class A or Class B sites is restricted to those pipingsystemsforwhichaFederalAgencyApprovedBrochurehasbeenissued.Military HandbookMIL-HDBK-1003/SAonExteriorDistributionof Steam,HighTemperatureWater, ChilledWater,NaturalGas,andCompressedAir(Ref 4)liststhetensystemsuppliersissued Federal Agency Letters of Acceptability required in NFGS-02694F. Thisstrictlimitationisnecessarytoensureuniformityinperformance.Oversightand controlof theapprovedsystemsuppliersfallwithinthecharterof theDODCommitteeon HeatingandCoolingExterior DistributionSystems.Thecharter goalis"toassurethat reliable heatingandcoolingexteriordistributionsystemsareavailableforusebytheparticipating agencies,"of which the Navyisaprimary member.It is alsopart of theCommittee charter "to assure that these systems can achieve a sufficiently long life to make them economically feasible whenusingGovernmentdesign,construction,operationandprocurementcriteriaand constraints."Thestatedmethodtoaccomplishthesegoalsis"toimproveproductsthatare currently availablein theshort term,and topartner withother professionalgroupstodevelopa national and/or industry standard in the long term"(Ref5). ThisinteragencyCommitteewasaprimarysourceofinformationandwaswell acquaintedwiththeissuesassociatedwithcondensatereturnandrelatednewtechnology.A reviewoftheprioritizedlistgeneratedbytheCommitteeontechnologytopicsrelatedto underground distribution systems (Appendix B) does not show a definitive need fordevelopment in theareaof condensate piping.In fact,conversationswithCommittee memberssuggestthat centralsteamdistributionisnot afavoredprocess(Ref 6).Other Navysourcesconfirmed this with the recommendation for conversion of central steam to high temperature hot water (HTHW) heating systemson areplacementbasis.Such isthe plan forthe Norfolk NavyShipyardin the conversion scheduled for the year 2005 (Ref 7). Current Practice The temperature and pressure rating for the condensate return piping varies by design for lowpressureandhighpressuresteamheatingsystems.It isdifficulttoidentifyamaximum exposure temperature forcondensate piping that is applicablein allsystems.An obvious upper limit forlow pressure steam systems is the saturated steam condition (15psig at 250F) that can result in theeventof steam trapfailure.Thisisthereason 250Fwaschosen forscreening the candidates for durable condensate piping.A lower temperature rating will apply tolow pressure systemswhereinsteamtrapdischargedoesnotventdirectlyintothecondensatepipe.These systems, designed with condensate wells, may suffer some loss of efficiency due tolost enthalpy but the condensate return condition is at a lower temperature (less than 212F). Thecondensatereturntemperatureforhigh pressuresteamsystemsistypicallyhigher thanthecondensatereturnedfromalowpressuresteamsystem.Selectionof amaximum exposure temperatureforhigh pressuresteam condensate piping would need tobebasedon the specific system design. Inallsystems,piping,fittings,andaccessoriesare typicallyspecifiedasconformingto American NationalStandardsInstitute(ANSI)StandardB31.1on Power Piping (Ref 8).MIL-HDBK-1003/8Afurtherstipulatesthatundergroundprefabricatedorpre-engineeredsystems must conformtoNFGS-02694Fon theExteriorUndergroundHeatDistributionSystemwhich includes the requirement for pre-approved system vendors. 4 Piping wallthicknessforthesteam carrier pipeisusuallyAmericanSocietyforTesting andMaterials(ASTM)A106Schedule40 (Ref 9)forsteelpipesizesthrough10inches,and minimumpipewallthicknessof 0.375inchforpipesizes12inchesandlarger.Wheresteel pipingisusedforcondensatereturns,NFGS-02694FrequiresSchedule80steelpiping.The Schedule80 pipingis moreappropriate because theextra wall thicknessover Schedule 40steel pipe provides a margin against corrosion, increasing the service life of the piping (Ref 10). Unpublisheddatafroma1991surveyconductedbytheNavalCivilEngineering Laboratory (now the Naval Facilities EngineeringServiceCenter) on Navy shore facilityboilers containedsomeinformationpertainingtodistributionpipingandcondensatereturn.Table2 shows a comparison of six Marine Corps bases selected from the survey data.These sites do not haverequirementsforcleansteam forshipsat port.Theintent of thistableistoshow general steam usageand theamount of condensate returnedforcases wherereturningthecondensateis viable. Table 2 Selected Survey Samples for Condensate Return Systems I Distribution I SteamCondensate LocationPipingUsageReturned I I MCRD Beaufort 195%Above 80% Heating!25-45%@ 150-190F Charleston, SC5%Shallow Trench20% Process ! MCCombat31% Above170% Heating35%@ 180F Development15% Direct BuriedII 0% Process I Command44% Shallow Trench!20% Losses Stafford, VA10% Tunnel i MCASN/A 180% Heating i20-55%@ 100-180F Kaneohe Bay, Ill20% Losses I I MCCamp5%Above IN/A 190%@ 280-300 F Pendleton 15%Shallow Trench I I i Camp Pendletort,190% Tunnel CA I MC Camp Lejeune77%Above170% Heating28-72%@ 180F Camp Lejeune, NC23% Direct Buried115% Process 15% Losses I MCLB!100% Tunnel20% Heating15% @220F Albany, GA i 80% Process ThefirstobservationthatcanbemadefromTable2isthatalargeportionof the distribution piping is installed aboveground or in tunnels.This would imply that direct access to thepipingwaspossibleforinspection,maintenance,andrepair.Again,thefocusof this investigation was to identify ways to minimize condensate loss and contamination.Yet, as in the cases of MCRD Beaufort, MC Combat Development Command, and MCAS Kaneohe where the majority of steam usage isfor heating(a recoverablesteam process),less than half of the steam 5 supplied for heating was reported as returned condensate.It isimplied from the survey data that thelow percentageof condensatereturnwasduetoinadequatecondensatereturnpiping.No informationwasavailableonwhetheror notthereturnedcondensatewascontaminated.Itis assumed that the returned condensate was suitable for reuse. ThesecondobservationmadefromTable2dataisthelargetemperaturerangeof the returnedcondensateforallsystems,fromalowof 100Ftothehighof 300F.Aswillbe discussed in the followingsection, theability tocarry high temperaturecondensate isbeyond the designofcompositepipingmaterial.Steelpipingistheonlymaterialidentifiedinthis investigation able tocarry high temperature condensate. Plastic Piping MilitarySpecificationMIL-P-28584B:PipeandPipeFittings,GlassFiberReinforced Plastic,AdhesiveBonded Joint Type,forCondensateReturn Lines(Ref 11)coversplastic pipe and fittingsmade fromepoxy resin andglassfiber reinforcements,together with epoxy adhesive necessaryfor joint assembly.Thespecificationcoverscondensatereturnserviceupto125-psi operatingpressureat250F.Additionalprotectionisprovidedinthefiberreinforcedplastic (FRP)pipedesignfromaboreliner madeof asmoothepoxyresin thatprotectstheglassfiber reinforcement. TheprimaryreasonforFRPpipeapplicationincondensatereturnpipingistomitigate corrosion and theresultant condensatecontamination.Aswillbediscussedin thenextsection on boiler water treatment,condensate piping corrosion is a cause forconcern and usually caused by high levelof dissolved C02 or by the presenceof oxygen.For this reason,FRPpipingisa desirable alternative over steel piping. It isreportedthatFRPpipinghasalower installation costover heavywallcarbonsteel (Ref12).FRPpipingcanbeassembledwithoutweldingorheavyliftingequipmentduring installationandafterwardduringmaintenance.Theadvertisedbenefitsof fiberglasspiping systems are: Economical installation Economical operation Long piping system lifetime Despite these benefitsand the MIL-P-28584Brequirement for product acceptancecyclic temperature testing to 300F using hot water,FRP pipe has a history of failure.Thecause of this failureisreportedaslivesteam exposure fromfailedopen steam traps(Refs13,14).Evidence of this typeof failuresuggestsimproper installation.MIL-HDBK-1003/8Aencouragestheuse of plasticcondensatepipingforundergroundinstallationsbutwarnsthatsteamtrapsshallnot dischargeintoplasticcondensate pipingbecauselivesteam cannot be tolerated.Instead,steam trap condensate should run to a flash tank or well where it can be pumped back to the boiler with no harm to the plastic piping.The disadvantage to this method is the potential loss of enthalpy at 6 thecondensatewell.Inaddition,if thecondensateisnotgravityreturned but must bepumped back to the boiler, the energy penalty to pump the condensate must be considered. It hasbeen suggested intheliterature thatFRP pipe failureis notstrictlyduetothermal stress and that limited cyclic exposure to steam does not cause failure.The failuremechanism is reportedtobeacombinationof thethermalstressfromsteamexposurecoupledwiththe occurrence of a severe water hammer concurrent with thedischargeof flashsteam (Ref 12).In anycase,followingMIL-HDBK-1 003/8ArecommendationsforproperFRPpipeinstallation eliminates this failure mechanism. Boiler Water Treatment TheDepartmentoftheArmy,inTechnicalNoteNo.86-3ontheUseof Diethylaminoethanol,Morpholine,andCyclohexylamine forCondensate Return LineCorrosion Prevention (Ref 15) provides a discussionon thecausesandtreatmentof condensatecorrosion. TheArmy reports that "corrosion ofreturn line systemsismorecommon in installations having extensive returnsystems,such ascentral energy plants."This maybe because themaintenance of distribution system piping is usually left to the pipe fitters or is otherwise orphaned because of diminished maintenancebudgets.Boiler operatorswithin the Navy tend todisown,in termsof maintenance, those parts of thesystem that are beyond 5 feetaway from the boiler building (Ref 16).TheArmyhasidentifiedthreefactorsascauseforcondensatepipingcorrosion(Ref 15). They are: Thepresenceof carbondioxideoriginatingfromboilermakeupwateralkalinity. Thepresenceof oxygenenteringthroughleakytraps,pumps,valves,andfittingsor withboilerfeedwaterthatisnotdeaeratedandtreatedwithsodiumsulfite. Potablewatercontaminationthroughleaksof mineralizedwatergenerallyathot water heater tubes. Properboilerwaterchemicaltreatmentandmaintenanceof thedistributionsystemto prevent leaksand contamination isa successful plan of action toensuresystem longevity.The recommendedpHlimitforcondensateinallreturnsystemsis7.5to8.0.Corrosionrates increase rapidly as the pH fallsbelow 7.5(Ref 15).Condensate return line corrosion prevention isanimportantaspectof boilerwaterchemistryand,if notrigorouslyadheredto,canleadto boiler damage. Economics MIL-HDBK-1003/SArecommendsusingASHRAEguidelinesfordeterminingthe economicsof returningcondensate,butitreportsthatcondensatereturnispreferredif itcosts lessthanusingandtreatingrawwaterformakeup(Ref 4).Thefactorslistedinfavorof condensate return are: 7 High area concentration of steam usage Restriction on condensate disposal High raw water treatment costs Water treatment space unavailable High cost of raw water High cost of fuelfor feedwater heating Missing fromthis factorlist is theconservation of energy and the conservation of water per the EnergyPolicyActof1992.Projectswithpaybackperiodsof10yearsorlessaretobe considered under the FEMP. Not returning thecondensatemaybemoreexpensivewhen thecost of theenergyin the formof sensibleheat and thecostof boiler makeuprateswithwatertreatmentareconsidered. Asanexample,lookingatjusttheheatlossatoneboilerplantatMCRDBeaufort, approximately44,600gallonsof condensatewaterwaslostin1990(excludingprocesssteam unrecoverable condensate).At the condensate return condition of345F at125-psi pressure, this waterlossrepresentsanenergylossof 105MBtu,orabout20percentof thesteamenergy delivered fromthat boiler plant.This result issignificant but would have tobe compared tothe installationandmaintenancecostsof condensatelinepipinginordertodeterminethecost effectiveness of maximizing returned condensate. Replacement Pipe Options Thereview of commercialliteratureaswellasdiscussionswithselect manufacturersof specialty piping did not identify any new materials forcondensate piping.Use of stainlesssteel piping for condensate return could eliminate the corrosion problem but not at an affordable price. For mostotherspecialtypipingmaterialsuchaspolyethyleneandpolyethylenelinedpipe,the limiting factor is a 200F temperatureexposure.If weconsider live steam exposure fromsteam traps,thismaterialhasnoadvantageoverFRP.Evenpolytetrafluoroethylene(PTFE)lined pipingisnotaworkablesolutiondespitePTFE'suppertemperaturelimitof 450F.Steam permeates through the PTFE liner and causes the liner to delaminate and collapse (Ref 17).This sort of lined pipingiscomparablein cost tostainlesssteelpipingandoffersnorealadvantage even when isolating the steam trap from the condensate return line through the use of hot wells. Repair Options Coatings.Theliteraturereviewresultedintheidentificationoftwocoating developmentsthat,uponfurtherresearch,provedunsuitabletoacondensatereturnpiping system.The firstcoating development wasa phenoliccoatingthat isprojected toprovidea10 percent improvement in service life.The Army,at their Civil Engineering Research Laboratory 8 (CERL), hassuccessfully taken a phenolic coating developed by Heresite Protective Coatings of Manitiowoc,Wisconsin,andappliedit toshortsectionsof steamcondensatereturnlinewithin the boiler room (Ref 18).Although evaluation is at the second year of a10-year trial, the coating hasdemonstratedareductionincorrosion.Asimilarsuccesshasbeenachievedusingthis coatingondomestichotwater heatexchangerstoimprovecoilefficiencythroughreductionof corrosion and scale.The single drawback to this process is the method of application,requiring anoven baketocure.Thisapplicationprocessisnot practicalforlongpipesections,anditis certainly not feasible for field restoration of condensate return line piping. TheothercoatingdevelopmentisanepoxyliningfromtheNavalResearchLaboratory (NRL)primarily forrestorationof shipboardpipingforusessuch aspotable water.Unlike the phenoliccoating,thisepoxycoatingcanbeappliedinthefield(Ref19)tosteelandcopper piping.The single disadvantage of this coating is its temperature limitation of hot distilled water at200F.Forlowtemperaturecondensatepipingsystemsisolatedfromaccidentalsteam exposure, thiscoating process may be advantageousasa meansof reducingcorrosion.Because steelisanodic,anydefectsinthecoatingwouldleadtolocalizedcorrosionpitting,butthis would be no more severe than if the pipe were untreated(Ref 20). Sliplining.Theliteraturereviewalsoreportedseveralvariationsof trenchlesspipeline rehabilitationtechniquesusingplasticmaterials.UndertheConstructionProductivity AdvancementResearch(CPAR)program,theU.S.ArmyCorpsof Engineersparticipatedina state-of-the-artreviewontrenchlesspipelinerehabilitation(Ref21).Theadvantagesand disadvantagesof several methodswere discussed.Each method involvedsome variation of the process,however,forthisinvestigation,thevariousmethodsweregroupedunderthecommon terminology"sliplining." Theslipliningmethodinvolvesinsertionof anewpipeof smallerdiameterintothe existing pipe where the annulus between the old and new pipe is usually grouted.The process is economical over new pipe replacement for underground systems because there is only a minimal requirementtodigtrenches.Accesstothepipelinerequiringslipliningcanbeatdiscrete locationssoasnottodisruptthelandscapeandnormalsurfaceactivities.Thoughtrenchless techniquesaretypicallyappliedtosewerrepairs,otherutilitiessuchaswater,naturalgas, electricity, and telecommunications have benefited from the techniques (Ref22). Thepracticeof sliplininghasbeen appliedtoavarietyof pipesizesand pipingmedia, however, there is no reported use for condensate return piping.The primary reason for not using thispiperehabilitationtechniqueisatemperaturelimitation.Thepipeliningmaterialusedin thistechniquecan be oneof severalunreinforcedpolymers,generallypolyvinylchloride(PVC) or polyethylene(PE).Neithermaterialissuitableforlivesteamexposureandwouldrateno betterthantheepoxycoatingtechniquepreviouslydescribed.Further,thereisasignificant differenceinthermalexpansionsof thispipecomparedtosteelpipe.Asanexamplefor equivalent diameter pipes, for one mile ofPE pipe inserted at 25F with an operating temperature of 100F,thesteelpipeexpands2.5feetand thePEpipeexpands43.5feet.For thisreason, reinforced thermosetting resins which have a thermal expansion coefficient closer to that of steel have been suggested over unreinforced polymer liner materials (Ref23). 9 Conversion to Hydronic Heating Systems When looking at a central plant required tosupport clean steam requirements forships at port,a common reason for not returning condensate back to the boiler isbecause thecondensate iscontaminated,either fromleaksintothesteamsystemor fromcorrosionproductsfrompoor conditioncondensatereturnlinepiping.Inbothcases,anattentivemaintenanceprogramcan minimize these effects.However,given past maintenance trends,an alternative approach seems reasonable. Convertingportionsof theboiler plantloadfromsteamtohydronicheatingcanreduce centralplantsteamrequirementstoprocesssteamandcleansteamforships.Othergeneral heating userscan be supplied hot water tomeet their needs.Thesteam to water heat exchanger would be located at the central boiler plant toprovide convenient maintenance and to reduce the lengths of condensate return lines.A closed circuit low temperature hot water (L THW) or a high temperaturehotwater(HTHW)districtheatingsystemwouldservetheneedsof theheating users while maximizing condensate return to the boiler. ManyEuropeancommunitiesemployL THWandHTHWdistrictheatingwithgreat success.Advantagesof thesecompletelyclosedcircuitsystemsincludeminimalcorrosionand less restrictions on distribution piping layout and elevations.It would seem that the elimination of the failure potential of numerous steam traps (and trap maintenance)isallthat theowner of a district steam heating system needs to hear to support a hydronic system. Though thisinvestigationdidnot havetheopportunitytoexamineactualconversionof district steam tohydronic heating, the literature reportsvery encouraging resultsforconversions oflowpressuresteamheatingsystemsonoldermulti-family(five-plusunits)andsmall commercial buildings.In one report,"energysavings ranged from13to39 percent of weather-normalizedtotalgasuse,withamedianof 27percent"anda"paybackof aboutnineyears" (Ref24).Theauthorspointoutthattheconversionof twopipesteamsystemswaseasier because the existing distribution piping could be used.. Itisreasonable,basedonpopularEuropeanusageandtheabilitytoconvertsteam systemstohydronicsystems,toconsiderhydronicsystemsforNavyfacilities.Theuseof hydronicdistrictheatingwouldbeparticularlyapplicableifboilerreplacementordistrict expansionwereintheplanning.Inbothcases,theconversioncostmaybeabsorbedintothe overallcost.If similarenergysavingsandpaybackperiodscanberealized,theadditional maintenance savings in manpower and fiscal resources would further justify the expenditure. CONCLUSIONS Specifically,thesearchforadurablematerialtoreplaceexistingmaterialsusedfor condensate return piping wasunsuccessful.Improvements tothe reliabilityand maintainability of condensate return lines can be accomplished through stricter adherence to existing installation specifications and operating procedures.The followingconclusions havebeen drawn asa result of this investigation: 1.Thedecision toreturn condensatetotheboiler islargely aneconomicone.For this reason,theexpenseof stainlesssteelpipingisnot justifiableeven thoughitisavailableandit 10 providesgoodcorrosion protection.Alongwiththemanysitefactors,theeconomicdecision needs toconsider nationalenergy efficiency goalsand conservation of environmental resources. Inallcaseswherecondensatereturniseconomical,boilerwatertreatmentshouldbethefirst practice for mitigating corrosion effects.Given clean steam requirementsat facilitieswith Navy shipsinport,thetreatmentof contaminatedcondensate(condensatenotmeetingcleanboiler water requirements) may not be economical and so justify disposal of the condensate. 2.FRPisanacceptable piping materialforlow pressuresteamsystemswheninstalled accordingtoguidanceprovidedinMilitarySpecificationMIL-P-28584B- PipeandPipe Fittings,GlassFiberReinforcedPlastic,AdhesiveBondedJointType,forCondensateReturn Lines (Ref 11) and in MIL-HDBK-1003/8A- Exterior Distribution of Steam, High Temperature Water,ChilledWater,NaturalGas,andCompressedAir(Ref 4).Theuseof FRPpipinghas fallenout of favorasa low cost substitute for steel piping in condensate return systems because of piping failures.FRP piping must not be directly connected tosteam traps.Given that there is not acurrent DODapproved vendor forFRP pipingsystems,the development of morespecific guidance, as in the form of an NFGS, is unnecessary. 3.The current process forusing DOD approvedsystem suppliers forconduit and piping products,albeit primarily forClass Aand Binstallationssites,isaneffectivemethod toensure installedsystemsmeetallgovernmentrequirementsforsysteminstallation,operation,and maintenance.TheDODCommitteeonHeatingandCoolingExteriorDistributionSystemsis successfully workingtowardimproved pipingsystems,includingcondensatereturn piping,and is accomplishing this through participation by the Army, Navy,and Air Force aswell as industry representatives. 4.Theuseof schedule80steelpipingforcondensatereturnlinesremainsthebest choice, in terms of availability and cost,over the materials considered in this investigation.The otherpipingmaterialsconsideredwereFRP,polymerlinedsteel,andstainlesssteel.The susceptibilityof steelpipingtocorrosion iseffectivelymitigatedbyan aggressiveboiler water treatment program.Unlikeplastic pipingor plasticlined piping,steelpipingisappropriatefor directconnectiontosteamtraps,andwhenproperlysizedisnotlimitedbytemperatureor pressure exposures. 5.The in-situ pipeline repair techniques of epoxy coating and slip lining are not suited to all condensate return lines repairs.For low temperature condensate piping systems isolated from accidentalsteam exposure,both processesmay beadvantageousand the decision torepair must be an economic one.These repair processes would not be applicable for high temperature steam pipingsystemswith condensate temperatures over 200F,or on anysystem with thepossibility of live steam exposure.If condensate temperature was effectively controlled through use of a hot well,then theepoxycoating technique would bemoreadvantageous than sliplining because the flow capacity of the pipe is not reduced by the liner. 6.Conversion of steam heating loads tohot water (hydronic) heating representsa viable alternative to continued steam distribution for facilitiesconsidering boiler system replacement or 11 expansion.The closed circuit hydronic system, with itslong history of success in theEuropean communityandreportedenergysavingsoversteamdistributionheating,iseasiertomaintain than a steam system primarily because steam traps are not used. RECOMMENDATIONS Thefollowingrecommendationsareprovidedbasedontheinvestigationresultsand conclusions drawn: 1.Providedthatreturningcondensatetotheboileriseconomicalbasedon thefactors presentedinthisreport,thelifeexpectancyof thecondensatepipingcanbeextendedby aggressiveboilerwatertreatment.TheArmy'sTechnicalNoteNo.86-3ontheUseof Diethylaminoethanol,Morpholine,andCyclohexylamine forCondensate Return LineCorrosion Prevention(Ref 15)shouldbecirculatedtoNavyboilerplantoperatorsasaguideforproper boiler water treatment. 2.Any Navy facilityconsideringsteam boilersystem replacementor expansionshould considerconvertingallorpartof theheatingloadovertoahydronicsystem.Aneconomic analysis should be performed to determine if the payback period is10 years or less.Considering thatthereislittledataavailableontheeconomicsof convertingadistributedsteamheating systemtohydronicheating,theearlycasesshouldbewelldocumentedforlateranalysisof achieved energy efficiency and cost payback period. 3.TheDODCommitteeonHeatingandCoolingExteriorDistributionSystemslistof technology issues associated with district heating systems isrecommended as guidance for Navy laboratory participation.Investigations of Committee selected technologies in concert with other DODserviceswillachievethe most value forthemoneyspent.Navy participation on thistri-servicecommittee willensure that Navy needsarefactoredintoanyinvestigations,particularly since the Navy has a unique requirement for clean steam for ship use at port. REFERENCES 1.Dan R.Williams.GuidetotheEnergyPolicyActof 1992.Lilburn,GA,FairmontPress, 1994. 2.AmericanSocietyof Heating,Refrigeration,andAir-ConditioningEngineers(ASHRAE). HVAC systems and equipment handbook.Atlanta, GA,1992. 3.NavalFacilitiesEngineeringCommand.GuideSpecificationNFGS-02694F:Exterior underground heat distribution system.Alexandria, VA, 31Dec1992. 12 4.DepartmentofDefense.MIL-HDBK-1003/8A:Exteriordistributionofsteam,high temperaturewater,chilledwater,naturalgas,andcompressedair.Washington,DC,15Aug 1990. 5.DepartmentofDefense.DODCommitteeonheatingandcoolingexteriordistribution systems, Washington, DC,1995. 6.GaryPhetteplace.Personalcommunication,U.S.ArmyColdRegionsResearchand Engineering Laboratory (USACRREL), Hanover, N.H., 20 Mar 1995. 7.David Knight.Telephone conversation, EFD Atlantic and John Kunsemiller,NFESC,Code ESC53, 20 Mar 1995. 8.American NationalStandardsInstitute.ANSIStandardB31.1:Power piping.New York, NY, 1989. 9.AmericanSocietyforTestingandMaterials.ASTMA106:Standardspecificationfor seamless carbon steel pipe for high-temperature service.Philadelphia, P A,1991. 10.Jim Kelly and David Knight.Telephone conversation, EFD Atlantic and John Kunsemiller, NFESC, Code ESC53, 22 Feb 1995. 11.MilitarySpecification MIL-P-28584B:Pipe and pipe fittings,glass fiber reinforced plastic, adhesive bonded joint type, for condensate return lines, 3 Mar 1989. 12.M.H.Anderson."Highperformancefiberglasspipehandlessteamcondensate,"in Proceedingsof the41st AnnualConference,Washington,DC,ReinforcedPlastics/Composites Institute, Jan 27-31,1986.The Society of the Plastics Industry, Inc.,1986. 13.Tom Harris.Telephone conversation, NAVFAC Code04Cand John Kunsemiller, NFESC, Code ESC53, 8 Feb 1995. 14.CharlieMarsh.Telephoneconversation,U.S.ArmyConstructionEngineeringResearch Laboratory (USACERL) and John Kunsemiller, NFESC, Code ESC53, 30 Jan 1995. 15.DepartmentoftheArmy.TechnicalNoteNo.86-3:Useofdiethylaminoethanol, morpholine, and cyclohexylamine forcondensate return line corrosion prevention.Washington, DC,1986. 16.HenryStudebaker.Personalcommunication,NavalFacilitiesEngineeringServiceCenter, Port Hueneme, CA, 23 Jan 1995. 17.GregHenthorn.Telephoneconversation,DOW ChemicalandJohnKunsemiller,NFESC, Code ESC53, 2 Feb 1995. 13 18.ConstructionEngineeringResearchLaboratories(U.S.).InterimReportFM-94/08:Field testresultsofcorrosion-resistantcoatingsforcarbon-steelsteamcondensatereturnlines. USACERL, Champaign, IL, Apr 1994. 19.Naval Research Laboratories.NRL!MR/6120--94-7629:Epoxy lining forshipboard piping systems, Washington, DC,Sep1994. 20.JimJenkins.Personalcommunication,NavalFacilitiesEngineeringServiceCenter,Port Hueneme, CA, 22 Feb 1995. 21.D.T.Iseley,M.Najafi,andR.D.Bennett."Trenchlesspipelinerehabilitationwithplastic materials,"BuriedPlasticPipeTechnology,vol2,ASTMSTP1222,DaveEckstein,Ed., American Society for Testing and Materials, Philadelphia, P A,1994. 22.B.GerardSchwartz Jr."Trenchless technologies offer viableoptions,"AmericanCityand County, Oct 1989, pp 30-33. 23.Benant E.Fruck."Plasticlinersforpipelinerejuvenation,"in Proceedingsof Interpipe'84 Conference,1984. 24.T.S.Dunsworth,M.J.Hewett,andM.S.Lobenstein."Energysavingsandfieldexperience from converting steam-heated buildings tohydronic heat,"in ASHRAE Transactions:Symposia. American Society of Heating, Refrigeration, and Air-Conditioning Engineers, Atlanta, GA,1993. BIBLIOGRAPHY Ahlgren,RoyC.E.(1994)."Asteam systems primer:high pressure steamsystems,"American Societyof Heating,Refrigeration,andAir-ConditioningEngineers(ASHRAE)Journal,Apr 1994. Ahlgren,RoyC.E.(1994)."Asteam systemsprimer:low pressuresteamsystems," ASHRAE Journal,Jan 1994. Butfield A.(1987)."Rolling down for relining," Civil Engineer, Jul1987. Construction EngineeringResearch Laboratories(U.S.)(1990).Development and testingof an anti-scale/corrosionresistantcoatingfordomestichotwaterheatexchangers,USACERLTR M-91!05/ADA231716.Champaign, IL, Dec1990. Duggan, Robert B.and Fredric R.Shaffer (1993)."Retrofitting for energy savings with hydronic heating systems," Specifying Engineer, Jun 1993. 14 Mizell,LeeandLarry J.Petroff (1993)."Sliplining:Design andinstallation considerationsfor polyethylenepipe,"PipelineInfrastructureII,MarkB.Pickell,Ed.,AmericanSocietyof Civil Engineers, New York, NY, Aug1993. Nance,CharlesH.(1993)."Trenchlessdiversityfuelsgrowthofconstructionactivities," Pipeline Infrastructure II, Mark B.Pickell, Ed., American Society of Civil Engineers, New York, NY, Aug1993. Sandstrum,SteveD.(1988)."Pipelinerehabilitationwithpolyolefinpipe,"Pipeline Infrastructure,Bruce A.Bennett, Ed.,American Society of Civil Engineers, New Yr ~ NY,Jun 1988. Stethem,W.C.(1994)."Single-pipehydronicsystemdesignandload-matchingpumping," ASHRAETransactions:Symposia,AmericanSocietyofHeating,Refrigeration,andAir-Conditioning Engineers, Atlanta, GA,1994 . 15 Appendix A LITERATURE SEARCH RESULTS A-1 LITERATURE SEARCH RESULTS Condensate Return Line Technology10 January1995 DIALOG(R)File 103: Energy SciTec(c)format only 1995 Knight-Ridder Info.All rts. reserv. 03744710GRA-94-70391; EDB-94-160676 Title:Field test results ofcorrosion-resistant coatings for carbon-steel steam condensate return lines.Interim report. Authors/editors:Hock, V.F.; Cardenas, H.; and Myers, J.R. Corporate source:Army Construction Engineering Research Lab.,Champaign, IL Publication date:Apr 94 (31p) Report number:AD-A-283208/7/XAB DIALOG(R)File103:Energy SciTec(c)format only1995 Knight-Ridder Info.All rts.reserv. 03685104GB-94-051425; EDB-94-101070 Title:Electric heaters for process applications. Authors:Armstrong, R. (Chemtec BV (United States)) Source:Hydrocarbon Technology International(United Kingdom)v1993issue. Coden:XZ2891 Publication date:1993p 88-90 DIALOG(R)File 103:Energy SciTec(c)format only 1995Knight-Ridder Info. All rts. reserv. 03352052NOV-92-030410; EDB-92-114809 Title:Replacement projects,risk analysis. Authors:Mycick,C.E.;Van Dyke, H.J.;and Mayer, G.R.(Bechtel, Inc.,San Francisco, CA) Title:Piping design handbook. Author/editor:McKetta, J.J.(University of Texas at Austin, Austin, TX) Publisher:New York, NY, Marcel Dekker Inc. Publication date:1992p1105-1111(1198 p) ISBN:0-8247-8570-3 DIALOG(R)File 103:Energy SciTec(c)format only 1995Knight-Ridder Info. All rts. reserv. 03351931NOV-92-030412; EDB-92-114688 Title:Flashing steam condensate. Author:Ruskin, R.D. Title:Piping design handbook Author/editor:McKetta, J.J.(University of Texas at Austin, Austin, TX Publisher:New York, NY, Marcel Dekker Inc. Publication date:1992p 405-41 0( 1198 p) ISBN:0-8247-8570-3 A-2 LITERATURE SEARCH RESULTS Condensate Return Line Technology10 January 1995 DIALOG(R)File8:Ei Compendex*Plus(TM)(c)1994 Engineering Info. Inc. All rts. reserv. 03788720E.I. No:EIP93121162292 Title:Film thickness measurement with an ultrasonic transducer. Authors:Lu,Qing; Suryanarayana, N.V.; and Christodoulu, Christodoulous Corporate source:Michigan Technological Univ, Houghton, MI Source:ExperimentalThermalandFluidSciencev ol 7, no.4, Nov 93, p354-361 Publication year:1993 CODEN:ETFSEOISSN:0894-1777 DIALOG(R)File8:Ei Compendex*Plus(TM)(c)1994 Engineering Info.Inc. All rts.reserv. 03714805E.I. No:EIP93091086108 Title:Strategic plan for a successful flow-accelerated corrosion program. Authors:Chexal,Bindi;Mahini,Ramtin;Munson, Doug; Horowitz, Jeff; Randall,Gus; and Shevde, Vishwas Corporate source:Electric Power Research Inst, Palo Alto, CA Conferencetitle:1993Pressure Vessels and Piping Conference. Conference location:Denver, CO E.I. Conference no.:19192 Source:Codes and Standards in A Global Environment, American Society of Mechanical Engineers,Pressure Vessels and Piping Division (Publication) PVP v 2591993. Publ by ASME, New York, NY, p 201-208 Publication year:1993 CODEN:AMPPD5ISSN:0277-027XISBN:0-7918-0986-2 DIALOG(R)File8:Ei Compendex*Plus(TM)(c)1994 Engineering Info. Inc. All rts.reserv. 03676216E.I. No:EIP93071019712 Title:Increasingsteamturbineefficiencyand reducing downtime by removing water soluble deposits with water injection. Authors:Roberts, Daniel E.; Felten, John; and Capps, Dennis Corporate source:Coors Brewing Co., Golden, CO Conference title:1993Industrial Power Conference Conference location:Denver, CO E.I. Conference no.:18670 Source:American Society ofMechanical Engineers,Power Division, (Publication) PWR v 201993. Publ by ASME, New York, NY, p 41-47 Publication year:1993 CODEN:AMEPEJISBN:0-7918-0679-0 A-3 LITERATURE SEARCH RESULTS Condensate Return Line Technology10 January 1995 DIALOG(R)File8:Ei Compendex*Plus(TM)(c)1994 Engineering Info. Inc.All rts.reserv. 03613666E.I. No:EIP93030737985 Title:Response ofNPP circulation circuit elements toabrupt changes in pressure. Authors:Syzarev, V.D.; Baranov, I.M.; Korotchenko, G.I.; Prostyakov, V.V.; and Menyailov, A.I. Corporate source:Inst of Power Engineering, Moscow, Russia Conferencetitle:WinterAnnualMeetingof theAmerican Society of Mechanical Engineers Conference location:Anaheim, CA E.I.Conference no.:17663 Source:FSI/FIV in Cylinder Arrays in Cross-Flow American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD v 2301992. Publ by ASME, New. York, NY, p 261-272 Publication year:1992 CODEN:ASMHD8ISSN:0272-5673ISBN:0-7918-1078-X DIALOG(R)File25:CLAIMS(R)/US Patents Abs(c)1995 IFI/Plenum Data Corp. All rts. reserv. 20365523021605 M!Monogroove Liquid Heat Exchanger Inventors:Brown Richard F (U.S.) and Edelstein Fred (U.S.) Assignee:United States of America NASA Administrator of Assignee Code:86504 Reassigned PatentIssueApplication NumberDateNumber Patent:us 4917173900417us 271266 Priority Applic:us 271266 Slip lining 3/611(Item 1 from file:6) 1171047NTIS Accession Number:PB86-130192/XAB Title:Jnsituformand Other Sewer Rehabilitation Techniques. (Final rept. Nov 77-Dec 83) NTIS prices:PC A07/MF A01 3/6/2(Item 1 from file:103) 01657246EDB-85-164026 Application Date 881115 771115 27 January 1995 Title:Sliplining a 42-in.cast iron gas main at Southport using an 800mm PE pressure pipe. 3/6/3(Item 1 from file:14) 0154312 Title:Strength ofHDPE pipes for the renovation ofpipelines by sliplining. A-4 LITERATURE SEARCH RESULTS Slip lining . 3/6/4(Item1 from file:8) 03940182 Title:Trenchless pipeline rehabilitation with plastic materials. 27 January 1995 Conferencetitle:Proceedings of the Symposium on Buried Plastic Pipe Technology: 2nd Volume. 3/6/5(Item 2 from file:8) 03705486 Title:Microtunneling ofvitrified clay pipe in theUnited States. Conference title:Proceedings of the International Conference on Pipeline Infrastructure II. 3/6/6(Item 3 from file:8) 03705453 Title:Trenchless diversity fuels growth ofconstruction activities. Conference title:Proceedings of the International Conference on Pipeline Infrastructure II. 3/6/7(Item 4 from file:8) 03705452 Title:Sliplining:Designandinstallationconsiderationsfor polyethylene pipe. Conference title:Proceedings of the International Conference on Pipeline Infrastructure II. 3/6/8(Item 5 from file:8) 03690677 Title:Big competition for small bore markets. 3/6/9(Item 6 from file:8) 03067301 Title:Rehabilitation ofdecant structure for coal slurry impoundment in Ohio. Conference title:Proceedings of the Symposium on Environmental Management for the 1990's. 3/6110(Item 7 from file:8) 03066371 Title:Large diameter sewer rehabilitation by sliplining in Florida. Conference title:Symposium on Buried Plastic Pipe Technology. 3/6/11(Item 8 from file:8) 03005099 Title:Sliplining rescues sewers and a small budget. 3/6/12(Item 9 from file:8) 02866785 Title:Trenchless technologies offer viable options. A-5 LITERATURE SEARCH RESULTS Slip lining 3/6/13(Item 10 from file:8) 02842955 Title:Pipeline renovation. 3/6114(Item 11from file:8) 02738667 Title:Sliplining with P E pipe repairs sewer lines. 3/6/15(Item12 from file:8) 02678270 Title:Sliplining with ductileiron pipe. Conference title:Pipeline Infrastructure Proceedings. 3/6/16(Item 13from file:8). 02678255 Title:Pipeline rehabilitation with polyolefin pipe. Conference title:Pipeline Infrastructure Proceedings. 3/6117(Item 14 from file:8) 02599544 Title:Slipliningfor sewer rehabilitation. 3/6118(Item 15 from file:8) 02338810 Title:Rolling down for relining 3/6119(Item16 from file:8) 02297845 Title:Failing sewer saved by jacking pipe through it. 3/6/20(Item 17 from file:8) 02118630 Title:Sliplining a 13 7 year old,20" diameter cast iron water main. 27 January 1995 Conference title:PlasticsforPipelineRenovationandCorrosion Protection in UK and Overseas. 3/6/21(Item 18 from file:8) 01682933 Title:Plastic liners for pipeline rejuvenation. Conference title:Interpipe '84,12th International Pipeline Technology Conference & Exhibition. A-6 LITERATURE SEARCH RESULTS Slip lining 3/6/22(Item19 from file:8) 01410977 Title:Sewers:Repairing beats replacing. 3/6/23(Item 20 from file:8) 00530492 Title:Seal manholes tight. Hydronic Heating 4/6/1(Item 1 fromfile:103) 03532751EDB-93-105232 27 January 1995 1 March 1995 Title:Energy savings and field experience fromconverting steam-heated buildings to hydronic heat. Title:ASHRAE transactions1993. Part 1 4/6/2(Item 2 from file:103) 02316490CANM-89-001010; EDB-89-062231 Title:Understanding hydronic heating systems. 4/6/3(Item 3 from file:103) 01468845EDB-84-166651 Title:Retrofitting for energy savings with hydronic heating systems. 4/6/4(Item 1 from file:8) 03684879 Title:Energy savings and field experience fromconverting steam-heated buildings to hydronic heat. Conferencetitle:Proceedings of the1993Winter Meeting of ASHRAE Transactions. Part 1. 41615(Item 2 from file:8) 01397566 Title:Retrofitting for energy savings with hydronic heating systems. 41616(Item 3 from file:8) 00554482 Title:Beneficial uses ofwaste heat from steam electric power plants. 4/6/7(Item 4 from file:8) 00443520 Title:Influence ofadiabatic air moistening on the energy consumption ofair conditioning plants. Title:Einjluss der adiabaten luftbefeuchtung aufdenenergieverbrauch von klimaanlagen. A-7 LITERATURE SEARCH RESULTS Hydronic Heating 7/611(Item1 from file:103) 03735820EDB-94-151786 Title:Control ofmultizone hydronic radiant floor heating systems. Title:ASHRAE transactions: Volume100, Part 1 7/6/2(Item 2 from file:103) 03735808EDB-94-15I774 Title:Single-pipe hydronic system design and load-matched pumping. Title:ASHRAE transactions:VolumeI 00, Part I 7/6/3(Item 3 from file:103) 03735800EDB-94-I5I766 Title:Why consider a primary-secondary hydronic pumping system. Title:ASHRAE transactions:Volume100, Part 1 7/6/4(Item 4 from file:103) 03678444FI-94-003233; EDB-94-094410 1 March 1995 Title:An experimental study on transient thermal behaviour ofnew hydronic radiant floor heating systems. Title:Indoor Air 193.Ventilation 7/6/5(Item 5 from file:I 03) 03647593CHF-94-0G4298; EDB-94-063559 Title:On saving pumping power inhydronic thermal distribution systems through the use ofdrag-reducing additives. 71616(Item 6 from file:103) 03587729EDB-94-003695 Title:European hydronic heating concepts for the American market oftoday. Conference title:Proceedings ofthe 1991Oil Heat Technology Conference and Workshop 7/617(Item 7 from file:I 03) 03532970EDB-93-I05451 Title:Hydronic radiant cooling:Overview and preliminary performance assessment. 7/6/8(Item 8 from file:I03) 03532744EDB-93-105225 Title:Heat emission rates ofhydronic terminal elements and their relationship to heating cost allocation devices. Title:ASHRAE transactions1993. Part 1 A-8 LITERATURE SEARCH RESULTS Hydronic Heating 7/6/9(Item 9 from file:103) 03459551EDB-93-038427 Title:Multi-source hydronic heat pump systems. Title:Innovativeenergy design for the'90s. 7/6/10(Item 10 from file:103) 03414636GRA-92-13240; EDB-92-177393 Title:Gas laboratory house hydronic-heating test results. Topical report, November 1990-April1991. 7/6/11(Item 11from file:103) 03339974GRA-92-42521; EDB-92-102731 Title:Development ofa hydronic Btu meter for multi-family applications. Final report, March 1,1990-April30, 1991 7/6/12(Item 12 from file:103) 02961005NOV -90-040086; EDB-90-178248 Title:Low-rise residential hydronic heating systems. 7/6/13(Item 1 from file:6) 1507681NTIS Accession Number: PB91-1302941XAB Title:Developmentofa hydronic BTU meter for multi-family applications. Final Report January1988-0ctober 1989 NTIS Prices: PC A04/MF AO 1 7/6/14(Item 1 from file:8) 03903277 Title:Multivariable integral control ofhydronic heating systems. 7/6/15(Item 2 from file:8) 03812046 Title:Designing and commissioning variable flow hydronic systems. 7/6/16(Item 3 from file:8) 03431220 1 March 1995 Title:Feasibility study ofthe use ofdrag-reducing additives toreduce pumping power in hydronic thermal distribution systems. Conferencetitle:Winter Annual Meeting of the American Society of Mechanical Engineers. 7/6/17(Item 4 from file:8) 03383150 Title:Converting constant-speedhydronic pumping systems to variable-speed pumping. Conference title:ASHRAE Winter Meeting- Technical Papers. A-9 LITERATURE SEARCH RESULTS Hydronic Heating 7/6/18(Item 5 from file:8) 03323174 1 March 1995 Title:In-slab hydronic heating systems warm rooms indoors,melt snow and ice outdoors. 7/6/19(Item 6 from file:8) 03080927 Title:Controlofa simulated dual-temperature hydronic system using a neural network approach. Conference title:1990 Annual Meeting of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Technical and Symposium Papers. A-10 AppendixB UNDERGROUND HEAT DISTRIBUTION SYSTEMS (UHDS) COMMITTEE TECHNOLOGY TOPICS Thisisaprioritizedlistingof researchordevelopmenteffortsresultingfromthe1993 AnnualResearchReviewWorkshoponUndergroundHeatDistributionSystems(UHDS)held 11August1993atNorfolkNavalStationinNorfolk,Virginia.Inattendancewere representativesfrombothdesignandO&MfromtheArmy,Navy,AirForce,Veterans Administration,andtheDepartmentof HousingandUrbanDevelopment.Itwasagreedupon that these efforts were currently needed in order to address the current problems associated with undergroundheat distributionsystemsbeingexperiencedwithin theDOD.It wasdecided that theeffortsthatarecurrentlyunderwayorprogrammedshouldberated"IA"withallother proposed work being ranked in numerical order.The research and/or development areas are: 1A.Survey ofDrainable/Dryable UHDS 1A.Standard Life Cycle Cost Analysis Procedures for HDS 1A.Experimental Heat Loss Measurement fromWet Conduit Piping 1A.Isolation Flange Kits and Cathodic Protection IA.Heat Loss Measurements at Ft. Jackson and Ft. Irwin IA.O&M and Repair Costs at Ft.Jackson, Ft.Riley, and Ft. Bragg 1A.Heat Distribution Systems Database IA.Maintenance Management System for Heat Distribution Systems 1A.Computer Aided Design and Operation ofHDS 1.Analysis of UHDS Survey 2.Optimization of Standard Shallow Trench Design 3.ECIP Justification for HDS 4.Low Temperature Hot Water Piping/Systems B-1 5.Temperature Limitations ofNon-metallic UHDS Materials 6.Water Spread Limiting Systems on Class A Sites 7.Operation/Supply Contract Specifications 8.Waterproofing of Manholes from Water Intrusion 9:Materials and Design Issues of Gland Seals 10.Insulation Testing (K-Factor and Chloride Content) 11.Sump Pump Guide Specification Improvement 12.High Reliability Thermostatic Steam Trap Investigation 13.Practical Leak Detection for Existing and New UHDS 14.Improved Inspection ofNew Construction and Qualification of Craft Workers 15.Improved Procurement and/or Detailed GuideSpecification 16.Pressure Testing ofNew Systems. 17.Investigation of Powder Insulation B-2 Appendix C CONDENSATE RETURN PIPING DESIGN TheAmericanSocietyofHeating,Refrigeration,andAir-ConditioningEngineers (ASHRAE)intheir1992SystemsandEquipmentHandbook(Ref2)liststhefollowing considerations for condensate return piping design: 1.Flow in the return line is two-phase, consisting of steam and condensate. 2.Pitch return lines downward in thedirection of thecondensate flow at 0.5inch per 10 feet to ensure prompt condensate removal. 3.Insulate the return line well,especially where the condensate is returned totheboiler or the condensate enthalpy is recovered. 4.Wherepossibleandpractical,useheatrecoverysystemstorecoverthecondensate enthalpy. 5.Equip dirt pockets of the drip legs and strainer blowdowns with valves toremove dirt and scale. 6.Install steam traps close to drip legs and strainer blowdowns for inspection and repair. Servicingissimplifiedbymakingthepipesizesandconfigurationidenticalfora given type and size of trap. 7.Whenelevatingcondensatetoanoverheadreturn,consider thepressureatthetrap inlet and the fact that it requires approximatelyI psi to elevate condensate 2 feet. C-1 AppendixD EXAMPLE OF ENERGY LOSS CALCULATIONS Example: Bldg.160 Boiler Plant (1990 Data) MCRD Beaufort Charleston, SC Usage: 80 percent Heating 20 percent Process Delivered 528.981MBtu of steam at conditions of345F at 125 psi Enthalpy of Evaporation {hfg) Enthalpy of Saturated Liquid {hf) =875.0 (Btu/Ibm) =315.8 (Btu/Ibm) Specific Volume of Saturated Liquid (vf)=0.01793(ft3!lbm) Mass of saturated steam (Ibm)=Total energy delivered (Btu) I Enthalpy hfg (Btu/Ibm) =528.981(106) I 875.0 =604,549.7 (Ibm) After condensing:mg=mf Volume ofliquid (ft3)=Mass ofliquid (Ibm) x Specific Volume of Liquid Vf(ft31lbm) =604,549.7 (lbm) x 0.01793(ft311bm) 10,839.6 ft3ofliquid Or, =81,085 gallons of condensate For a 75percent condensate loss, less the 20 percent of process steam that is not returnable, 55percent of available condensate represents lost energy savings potential. Volume of available condensate (gal)=Volume ofliquid (gal) by percent available(%) =81,085 gallons x 0.55 =44,597 gallons Or, =5961.8 ft3 D-1 Energy lost (Btu)=Mass of saturated steam (Ibm) x Enthalpy hf(Btullbm) (5961.8 ft3/ 0.01793(ft3/lbm)) x 315.8 (Btu/Ibm) 105.0 MBtu D-2 DISTRIBUTION LIST AFBI314CSG/DEEE,LITTLEROCK AFB,AR AFBI SSDIDEC,VANDENBERGAFB,CA ARMYCRREL ICRREL-EA(PHETTEPLACE),HANOVER,NH CBCICODE 470.2,GULFPORT,MS COMNAVFACENGCOM ICODE SOT,ALEXANDRIA,VA COMSPAWARSYSCOMISPAWAR 005-03A,WASHINGTON,DC DEFENSE DEPOT IE.FRONK,ENGR TECH,OGDEN,UT DOEIFEDERAL ENERGY MGT PROGRAM,WASHINGTON,DC DOE IINEL TECHLIDREPORTSSTA,IDAHOFALLS,ID DRURY COLLEGEISPRINGFIELD,MO DTRC ICODE 2705,MCPHERSON,ANNAPOLIS,MD DTRCEN ICODE 522,ANNAPOLIS,MD EPA I REGITLIB,NEW YORK,NY EPAIREGITILIB,PHILADELPHIA,PA FELEC SVCS,INCIDE-3(R MCCUDDY),COLORADA SPRINGS,CO GOVERNOR'SENERGYOFFICEIHYLAND,CONCORD,NH GSAIREGITI,ENERGYCOORD,PHILADELPHIA,PA INDIAN INST OFTECH ICENTRE OFENERGYSTUDIES,NEWDELHI LOUISIANA INAT RES DEPT,R&D,BATONROUGE,LA MARCORPSI1STDIST,DIR,GARDENCITY,NY MCLBIMAINTOFFR,BARSTOW,CA MCLBI PWO,BARSTOW,CA MISSOURIINATRESDEPT,ENERGYDIV,JEFFERSONCITY,MO NASIKIRBY,MERIDIAN,MS NASADAKICODE70-800,FPO AP, NASCECIL FIELDICODE1833, JACKSONVILLE,FL NASFALLON ICODE186,FALLON,NV NASLEMOORE ICODE R102,LEMOORE,CA NASPUGET SOUNDICODE418,SEATTLE, WA NASA HDQTRSIWICKMAN,WASHINGTON,DC NAVAMPHmBASEICODEN491,NORFOLK,VA NAVCOSSYSCENICODE 7410EH,PANAMA CITY,FL NAVFACENGCOMICODE 03R (BERSSON),ALEXANDRIA,VA NAVSHIPYDICODE 453-HD,PORTSMOUTH,VA NAVSTAICODE183,CHARLESTON,SC NAVSTA ICODE 610,SANDIEGO,CA NAVSTAICODE 634,SANDIEGO,CA NAVSTA TREASUREISLANDICODE83,SANFRANCISCO,CA NAVSUBBASICODE834,GROTON,CT NAVSUBBASBANGOR ICODE831,SILVERDALE,WA NAVSUPCEN ICODE 73,NORFOLK,VA NAVSUPPACTINAPLES,ITALY,FPO AE NAVTRASTA ICODE17.4,SANDIEGO,CA NAVTRASTA ICODE 523,ORLANDO,FL NAVUSEAWARENGSTA ICODE 073,KEYPORT,WA NAVWEAPSTA ICODE 09202,CONCORD,CA NAVWEAPSTAICODE 0923,SEAL BEACH,CA NCCOSCICODE811,SANDIEGO,CA NSGA ICODE 90,SONOMA,CA OCNR ICODE1114SE,ARLINGTON,VA ROICCICODE 05(MARK KEAST),FPOAE ROICCICODE R-30DM,CHARLESTON,SC ROICCICODE RS4,FPO AE ROICCNAVBASEICODE 30BD,CHARLESTON,SC SCIENCEVU RESEARCHI JOHN DCUNNINGHAM,EASTSWANZEY,NH SOUTHNAVFACENGCOMICODE 403(GADDY),NORTHCHARLESTON,SC STATE HOUSE IOFFICEOFENERGYRESOURCES,AUGUSTA,ME TENNESSEEIENERGY DIV,NASHVILLE,TN UNIVOFCALIFORNIAI ENERGY ENGR,DAVIS,CA USAFE IDE-HFO,RAMSTEINAB,GE,APOAE USDA I FOR SER REG10,JUNEAU,AK USDA I FOR SVCREG1,TECH ENGRS,MISSOULA,MT USDAIFOR SVCREG 2,ENGR TECHSTAFF,LAKEWOOD,CO USDA IFOR SVCREG 3,ENGR TECH STAFF,ALBUQUERQUE,NM USDAIFOR SVCREG 4,TECHSTAFF,OGDEN,UT USDA IFOR SVCREG8,TECH ENGRS,ATLANTA,GA USDAIFOREST EXPER STA,ST PAUL,MN USDA IROCKYMTN FOR &RNGEXPER STA,FAC ENGRG,FORTCOLLIN USDA ISEFORESTEXP STA,ASHEVILLE,NC USNA IMECH ENGR DEPT(C WU),ANNAPOLIS,MD USNAI MECH ENGRG DEPT (POWER),ANNAPOLIS,MD USNHYOKOSUKAICODE13.3,FPOAP USPSIMGR,PLANT MAINT,ALBANY,GA