Corrosion Control in Distribution Pipes - Ohiowater.org

Corrosion Control for Water &Wastewater SystemsPresented By:James T LaryCorrpro1055 West Smith Rd.Medina, OH 44256®Tel. 330-241-6615email: jlary@corrpro.comhttp://www.corrpro.com

Temporary Fix ?

Corrosion

Corrosion - A Natural ProcessIRON OXIDE REFINING MILLINGIRON,STEEL,PCCP CORROSION IRON OXIDE

Corrosion Cell on Buried PipingCathodic Area( + )Anodic Area( - )StructureCurrent Flow ThroughSoil or Water

Corrosion of Metallic Structure

Water(Electrolyte)Anodic Area(Corrodes)Metallic Return PathCurrentFlowCathodic Area(Protected)Tank Wall

History of Iron PipeCast Iron- Introduced to North America during the 1800’s andinstalled till the 1970’s.- Early on, statically cast process produced a thickwalled, heavy pipe.- No longer produced in North America.Ductile Iron - Introduced in 1955 as an improvement tocast iron.- Centrifugal casting process produces a thinnerwalled, lighter pipe which is stronger andmore ductile than cast iron.

Cast (Grey) IronFailuresGraphitization leaves pipe brittle and weakened.

1.58 in.1.22 in.0.94 in.0.87 in.0.58 in.0.43 in.0.38 in.0.21 in.1908 1952 1957 1957 1976 1985 1991 LessCLD CL 150 CL 23 CL 22 CL 3 CL 50 CL 150 TolerancesCI CI 18/40 21/45 DI DI DICI CIActual size of AWWA Specification Thickness Reductions for 36-inch DiameterCast and Ductile Iron Pipe - 1908 to Present (150 PSI Operating pressure)

Ductile IronPitting (concentrated)corrosion attack on ductile ironpipe.

Adverse Conditions for Metallic Pipe- High Chlorides- Low Soil/Water Resistivity- High Sulfates- Acidic Soils- Wet/Dry Fluctuations- Bimetallic Couplings- Stray Current Interference

PRACTICAL GALVANIC SERIESMaterialPotential*Pure Magnesium -1.75Zinc -1.10Aluminum Alloy -1.00Cadmium -0.80Mild Steel (New) -0.70Mild Steel (Old) -0.50Cast/Ductile Iron -0.50Stainless Steel -0.50 to + 0.10Copper, Brass, Bronze -0.20Gold +0.20Carbon, Graphite, Coke +0.30* Potentials With Respect to Saturated Cu-CuSO 4 Electrode

Coupling to Dissimilar MetalsMetallicConnectionCopper service (Cathode)- 300mVIron pipe (Anode)- 500mVCORRPROC O M P A N I E S I N C

Copper Service Connections

Anode Installation Prevents Corrosion onCopper Service LineNon metallic orPolyethylene EncasedDuctile Iron MainAnode Connection to LineAnode

Water Wells

Meter Vaults(Keep dry if possible)

Gate Valve Corrosion

Dissimilar Surface ConditionsPipe(Cathode)ThreadsBright Metal(Anode)Scratches(Anode)CORRPROC O M P A N I E S I N C

Corrosion Caused by DifferentialAerationAerated SoilOxygenAvailable(Cathode)PipeLowOxygen(Anode)CORRPROC O M P A N I E S I N C

Gas Pipeline(-)Cathodic ProtectionRectifier(+)Anode GroundbedCurrent Discharge(Corrosion)Current Discharge(Corrosion)Water PipelineStray Current Due to Impressed Current CathodicProtection System

Impressed Current CP System on Oil/Gas Lines canCreate Stray Current Problem on Water Lines

PowerStationStray Current by DCOperated Transit SystemsPipelineCurrent exit (Anode)Current entrance (Cathode)

Stray Current

Bonding Across a Bell and Spigotor Slip-jointThermite brazedconnection coated withbitumous compoundCopper wire withdirect burial insulation

Computerized Potential Logging SurveyTestStationBackpackComputer UnitChainer/WireDispenser &CounterReferenceCellsBondedJointsPolywrapPipeline

Potentials (millivolts)00+0500+1000+1500+2000+2500+3000+3500+4000+4500+5000+5500+6000+6500+7000+7500+8000+8500+9000+9501+0001+0501+1001+1501+2001+2501+3001+3501+4001+45Chainage00+0500+1000+1500+2000+2500+3000+3500+4000+4500+5000+5500+6000+6500+7000+7500+8000+8500+9000+9501+0001+0501+1001+1501+2001+2501+3001+3501+4001+45CIS Survey8" Pipeline Rivana River N to SClose Interval Survey Data-2500Chainage-2500Potential (millivolts)-2000-2000-1500-1500-1000-1000-500-50000Close Interval DataInterrupted SurveyClose Interval DataPG/WFA Survey

Polyethylene Encasement- Follow manufacture’s and AWWA recommendations toinsure proper installation of polyethyleneencasement.- In extremely corrosive areas, additional methods (bondingof joints, cathodic protection, may be required).

Polyethylene Encasement of Ductile Iron Pipe-Follow DIPRA installation procedures-Clean pipe before installing polywrap-Repair tears or damage to encasement-Engage an inspector to oversee installation

Galvanic Anode on PolyethyleneEncased Ductile Iron Pipe

PRACTICAL GALVANIC SERIESMaterialPotential*Pure Magnesium -1.75Zinc -1.10Aluminum Alloy -1.00Cadmium -0.80Mild Steel (New) -0.70Mild Steel (Old) -0.50Cast/Ductile Iron -0.50Stainless Steel -0.50 to + 0.10Copper, Brass, Bronze -0.20Gold +0.20Carbon, Graphite, Coke +0.30* Potentials With Respect to Saturated Cu-CuSO 4 Electrode

Cathode(Protected)Anode

Galvanic AnodeStructureMagnesiumAnodeCurrent Flow

Thermit Weld to Pipe

Anode InstallationAugered holeGalvanic anodeConnection to piping

Access to Pipe

Number of Breaks25100 Breaks Prior to Cathodic Protection3 Breaks After Cathodic Protection2015101988 C.P. TotalsLength Protected = 12,780 feet5074 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95YearBreak Records for Water Mains Cathodically Protected in 1988

Temporary Fix ?

Repair of Break ShouldInclude Anode InstallationIncompleteComplete

Water Leak Repair KitIncludes:Installation instructions.One day onsite technicalassistance.Cathodic protectioncomponents/connection materialssuitable for 10 repairs.

Lower Stress Area(Cathode)PipeThreaded BoltHigher Stress Area(Anode)Stress CorrosionMetallic Coupling

Cathodic Protection of Metallic FittingAnode Lead Wire ConnectionPipeGalvanicAnodeMetallic Coupling

Anode Installed on Metallic Fitting

Meter Vaults(Keep dry if possible)

Bolt Corrosion(due to water/sludge)Bond CablesAnodeConnectionWater/SludgeMeter Vault CorrosionMeter Vault with Galvanic Anode

For New or Refurbished Tanks

Suspended Horizontal Anode SystemTop View DiagramSubmerged AnodeSupport SystemAutomatic PotentialControl RectifierPressure Entrance Fitting

Horizontally Submerged Cathodic Protection Systemin Water Storage Tank

Annual Maintenance

Corrosion of Clarifier Center Well

Pumping StationsCORRPROC O M P A N I E S I N C

Depleted & Refurbished CathodicProtection for Lift Stations

AC Mitigation

Investigative Structure (Existing)Corrosion Assessment• Review of General Characteristicsof Water System- Age- Material Type- Wall Thickness- Construction Practices• Review Break / Leak History• Field Survey- Soil Conditions (Resistivity,Moisture Content, ChemicalAnalysis)- Electrical Test• Data Analysis & Risk Management• Priority Index (Identification ofOpportunities to ReduceReplacement / Repair Costs)

Insituform

TrafficDisruptionsWater LossFireProtectionDamagesLegal &EnvironmentalClaims

QUESTIONS ?James T LaryCorrpro Companies, Inc.1090 Enterprise DriveMedina, Ohio 44256330-723-5082 (x1215)email jlary@corrpro.com

Design Decision ModelFor Ductile Iron Pipe

Cathodic Protection of Metallic FittingAnode Lead Wire ConnectionPipeGalvanicAnodeMetallic Coupling

Computerized Potential Logging SurveyTestStationBackpack ComputerUnitChainer/WireDispenser & CounterReferenceCellsBonded JointsPipeline

Corrosion of Metallic Structure

Vertically Suspended High Silicon Cast IronAnode String

SummaryReducing corrosion rates on existing water distributionpiping will result in a reduction of the number of breaksand also extend the operational life.Corrosion control measures should be consideredduring the design stage for any new metallic pipingans storage tank installations.

Design Decision ModelFor Ductile Iron Pipe

AbovegroundStorage TankTest/AccessStationGrade3” PVC 20%Exposure10’TypicalAnode MaterialABOVEGROUND STORAGE TANKCATHODIC PROTECTIONAnode Tube

The estimated annual cost to repairwater piping breaks in NorthAmerica alone is estimated to be*:based on 250,000 breaks at a repair cost of $5,875.00 U.S.D. each

Budget Estimate for CompleteCathodic Protection System for1MMG Water Tank$12,000

New PipingPHASE I- Obtain drawings of proposed route- Conduct independent field investigation:a) Soil resistivity studyb) Identify foreign pipeline crossingd) Identify AC potential influencee) Collect soil samples (moisture content,chlorides, pH, sulfate ions concentration,conductivity)- Stray current investigation

Corrosion Protection DesignPhase IIPrepare Bid Quality Specifications for:- Coatings or Polyethylene Encasement- Test Stations (Monitor Corrosion Rates)- Bonded Joints- Stray DC/AC Mitigation- Cathodic Protection- Combination of Multiple Items- Review Submittals/Onsite Periodic Inspection

Lower Stress Area(Cathode)PipeThreaded BoltHigher Stress Area(Anode)Stress CorrosionMetallic Coupling

Transformer Rectifier

Insituform

Yard Piping Deep Anode GroundbedImpressed Current SystemAnode Junction BoxRectifier+ -ImpressedCurrent AnodesPiping

Factory Installed Cathodic Protection Systems

Bi-Metallic Corrosion BetweenCarbon Steel Tank & Stainless Steel Ladder

Corrosion Control for WaterSystem Piping Results in Reductionof Water LossPresented By:James T LaryCorrpro Companies, Inc1090 Enterprise Dr.Medina, OH 44256Tel. 330-723-5082 (x1215)®email: jlary@corrpro.comhttp://www.corrpro.com

Repair of Break ShouldInclude Anode InstallationIncompleteComplete

Annual Cathodic Protection Survey

Corrosion Control for Water& Wastewater SystemsPresented By:James T LaryCorrpro Companies, Inc1090 Enterprise Dr.Medina, OH 44256Tel. 330-723-5082 (x1215)®email: jlary@corrpro.comhttp://www.corrpro.com

Corrosion is the leading contributor to cast andductile iron water system breaks!

Bolt & Nut Corrosion

Inspection of CP System

Basic Corrosion CellGround SurfaceBuried PipeAnode-600mVCathode-550mV1) Anode2) Cathode3) Electrolyte4) Electrical ConnectionCORRPROC O M P A N I E S I N C

Structures- Piping (Distribution/Transmission)- Metallic Fittings- Water Storage Tanks- Clarifier Units- Lift Stations

Corrosion Can be Defined as Either: PracticalTendency of a Metal to Revertto its Native State ScientificElectrochemical Degradationof Metal as a Result of a Reactionwith its Environment

History of Iron PipeCast Iron- Introduced to North America during the 1800’s andinstalled till the 1970’s.- Early on, statically cast process produced a thickwalled, heavy pipe.- No longer produced in North America.Ductile Iron - Introduced in 1955 as an improvement tocast iron.- Centrifugal casting process produces a thinnerwalled, lighter pipe which is stronger andmore ductile than cast iron.

Dissimilar SoilsPavementSandy LoamClaySandy LoamCathodeAnodeCathodeDe-icing salts?Fertilizers?CORRPROC O M P A N I E S I N C

CARBON ROD(CATHODE)+0.30mVWIRE(CONDUCTOR)ZINC CASE(ANODE)-1.10mVMOIST PASTE(ELECTROLYTE)

Proper Handling & Installation ofPolyethylene Ductile Iron Pipe

Corrosion of iron when coupled to copper service line.

Corrosion Pitting

Dissimilar Surface ConditionsPipe(Cathode)ThreadsBright Metal(Anode)Scratches(Anode)CORRPROC O M P A N I E S I N C

Corrosion Caused by DifferentialAerationAerated SoilOxygenAvailable(Cathode)PipeLowOxygen(Anode)CORRPROC O M P A N I E S I N C

CP Benefits: - Triple life of coating- Reduce maintenance cost

Number of Breaks2094 Breaks Prior to Cathodic Protection1 Breaks After Cathodic Protection151993 C.P. TotalsLength Protected = 55,360 feet105074 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95YearBreak Records for Water Mains Cathodically Protected in 1993

Coating Flaws (Holidays)

Number of Breaks2094 Breaks Prior to Cathodic Protection1 Breaks After Cathodic Protection151993 C.P. TotalsLength Protected = 55,360 feet105074 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95YearBreak Records for Water Mains Cathodically Protected in 1993

TrafficDisruptionsWater LossFireProtectionDamagesLegal &EnvironmentalClaims

Corrosion on damaged polyethylene encased pipe.

Corrosion of pre-stressed concrete cylinder pipe (P.C.C.P.).

Cathodic Protection Test StationTestStationMagnesiumAnodeStructure

Suspended Vertical Anode SystemSupport System Bolted toRoof for Bowl Anodes andReference ElectrodesTop View DiagramAutomatic PotentialControl Rectifier

Cathodic Protection for Hot Water Tanks

Corrosion

PCCP Failure

PowerStationStray Current by DCOperated Transit SystemsPipelineCurrent exit (Anode)Current entrance (Cathode)

Pre-stressed Concrete Cylinder Pipe (PCCP)

Give Me a BreakFundamentals of Pipeline CorrosionPresented By:James T LaryCorrpro1090 Enterprise Dr.Medina, OH 44256®Tel. 330-723-5082 (x1215)email: jlary@corrpro.comhttp://www.corrpro.com

Corrosion Control & Cathodic Protectionof Water & Wastewater SystemsPresented By:James T LaryCorrpro1090 Enterprise Dr.Medina, OH 44256®Tel. 330-723-5082 (x1215)email: jlary@corrpro.comhttp://www.corrpro.com

Pipeline Inspection ReportInspector name_________ Date____ Address of pipeline inspection ________________ Leak? Yes____ No____ File Number:_____________1) Type of Pipe: cast iron_____ ductile iron____ carbon steel___ copper______ carbon steel_____ non metallic_____ other____2) Diameter of pipe _____” Pipeline Name_________ Service Type: Water____ Wastewater____ Estimated date of pipe installation______ Depth of pipe______’3) Type of Pipe: Distribution____ Transmission____ Service_____ Hydrant _____ Mechanical joint_____ Fasteners_____ Other____ Unknown____4) Type of Coating: Polyethylene Encased____ Shop applied coating___ No Coating____ Tape Wrap____ Unable to determine____5) External Pipe Condition: Very Good____ Good____ Poor____ comments:_______________________________________________________________________________________________________________________________________________________________________________________________________________6) Is corrosion pitting evident? ____ Yes ____ No Number of Pits______ Typical Size of Pits______ Quantity of pits:______7) Is graphitization evident (longitudinal or circumferential breaks) ____Yes ____ No8) Is the pipe installed in (check off appropriate items): Industrial area____ Residential area____ Rural area____ Near street or road ____Near creek or waterway ____ In reclaimed land___ Near oil or gas pipelines____ Near high voltage lines ____.8) Describe soil conditions where inspection occurred: wet____ dry____ clay soil ____ rocky soil____ cinders ____ other____________________9) Where soil samples obtained, sealed and analyzed for chlorides, moisture content, pH, sulfides, resistivity? If yes results were: _____________________________10) Were previous repairs made on the pipeline (leak clamps, etc) Yes____ No ____. Was new pipe installed____ Yes ____ No.11) Was a repair clamp installed on the pipe during inspection ___ Yes ___ No12) Was a galvanic anode installed as part of the inspection process? ___ Yes ___ No, if yes size and quantity13) Please relay additional comments:_______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________14) Plan of Action____________________________15) Insert digital photos below:

Corrosion Can be Defined as Either: PracticalTendency of a Metal to Revertto its Native State ScientificElectrochemical Degradationof Metal as a Result of a Reactionwith its Environment