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State of the Art Cathodic Protection Practices and Equipment State of the Art

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State of the Art Cathodic Protection Practices and Equipment State of the Art State of the Art Cathodic Protection Practices and Equipment State of the Art Definition: The level of development (as of a device, procedure, process, technique, or science) reached at any particular time usually as a result of modern methods Cathodic Protection 9 Type 9 Materials 9 Installation 9 Monitor / Survey Techniques Types of Cathodic Protection Sacrificial Anode ¾Small Current Requirement • Well Coated Structures • Isolated Structures ¾Low to Medium Soil Resistivity Types of Cathodic Protection Impressed Current ¾ Large Current Requirement • Poorly Coated Structures • Shorted Structures ¾ High Soil Resistivity Sacrificial Anodes Magnesium & Zinc Typical Sacrificial Anode Zinc Ribbon TYPICAL SACRIFICIAL ANODE INSTALLATION SINGLE ANODE MULTIPLE ANODE GRADE GRADE PIPE PIPE AT PIPE DEPTH TO 5' TYPICAL ANODE ANODE ANODE ANODE 10'-15' MIN 5' TO 15' ANODE FOR MAGNESIUM TYPICAL 5' MIN FOR ZINC 5' MIN Typical Sacrificial Anode Installation Typical Sacrificial Anode Installation Typical Sacrificial Anode Installation Ribbon Anode Impressed Current Rectifier ¾ Constant Voltage ¾ Constant Current ¾ Auto Potential ¾ Pulse ¾ Alternative Power ¾Solar ¾ Thermo Electric ¾ Wind ¾ Hydro Impressed Current Anode Graphite Impressed Current Anode High Silicon Cast Iron Impressed Current Anode Mixed Metal Oxide TYPICAL IMPRESSED CURRENT ANODE INSTALLATION DISTRUBUTED PIPE PIPE - RECTIFIER + ANODE ANODE ANODE ANODE ANODE ANODE TYPICAL IMPRESSED CURRENT ANODE INSTALLATION REMOTE RECTIFIER ANODES - + PIPE 200' TO 500' TYPICAL TYPICAL IMPRESSED CURR 50' TO 400' TYPICAL PIPE - + DEEP ENT ANODEINSTALLATION SLURRIED BACKFILL BACKFILL SLURRIED WITHIN ANODE GRADE GRADE TO ANODE JUNCTION BOX MINIMUM 2'-0" BURIAL SURFACE CASING TO 40 FT VENT PIPE SAND / BENTONITE MIXTURE ANODE LEAD WIRES / HALAR 200' ANODES 10 EACH ON 10 FT CENTERS 125' 75' LOW RESISTANCE BACK-FILL BOTTOM FILLED SLURRIED 10" Impressed Current Anode Installation Distributed or Remote Impressed Current Anode Installation Deep Storage Tank Bottom CP New Existing Vacuum Excavation • Utility Locating • Anode Installation • Reference Cell Installation • Test Station Installation • Depth of Cover Survey • Expose Pipeline for Coating Inspection • Subsurface Utility Engineering Vacuum Excavation Utility Locate Vacuum Excavation Anode / Test Station Installation Cathodic Protection Testing ¾ Equipment ¾ Tools ¾ Materials ¾ Survey Methods C.P. TEST EQUIPMENT 0.000 HIGH INPUT IMPEDANCE DIGITAL VOLT METER + 10 M OR GREATER COPPER/COPPER SULFATE REFERENCE CELL CLEAN, FULLY CHARGED & CALIBRATED TEST WIRES WITH ALLIGATOR CLIPS SELECTION OF SHORT & LONG WITH NO SPLICES CLEAN WATER CLEAN WATER TO SATURATE THE TEST LOCATION MISC. HAND TOOLS TO MAKE MINOR REPAIRS ON-SITE Data Collection Read Only Self Storage Reference Cell / Electrode • Contaminated every SATURATED COPPER time it gets used SULFATE SOLUTION O-RING SEAL 9 Clean Regularly PURE COPPER ROD 9 ELECTRODE BODY Check Regularly COPPER SULFATE O-RING SEAL CRYSTALS • The “Weakest Link” in POROUS PLUG Cathodic Protection Testing Cathodic Protection Criteria NACE SP0169 1. ‐850 mV with IR Drop Considered 2. ‐850 mV Polarized 3. 100 mV Polarization CP Test Location / Test Station C.P TESTING - PERMANENT REFERENCE CELL REFERENCE VOLT METER CELL TERMINAL - 0.850 V + STRUCTURE TERMINAL PERMANENT REFERENCE CELL PIPE 1. CONNECT (+) LEAD OF VOLT METER TO STRUCTURE TERMINAL 2. CONNECT (-) LEAD OF VOLT METER TO REFERENCE CELL TERMINAL 3. READ & RECORD MEASURED POTENTIAL Permanent Reference Electrode C.P TESTING - PORTABLE REFERENCE CELL VOLT METER VOLT METER STRUCTURE - 0.850 V - 0.850 V TERMINAL + + C.P. TEST STATION REFERENCE CELL STRUCTURE TEST WIRE PIPE PIPE 1. CONNECT (+) LEAD OF VOLT METER TO STRUCTURE TERMINAL 2. CONNECT (-) LEAD OF VOLT METER TO REFERENCE CELL TERMINAL 3. PLACE REFERENCE CELL DIRECTLY OVER OR ADJACENT TO PIPE 4. READ & RECORD MEASURED POTENTIAL PROPER REFERENCE CELL PLACEMENT .850V 100' (TYPICAL) GRADE PIPE ANODE ANODE Coupon Test Station • IR Free Potential Reads • No Need to Interrupt: 9 Rectifiers 9 Sacrificial Anodes 9 Foreign Bonds • Calculate Metal Loss Remote Monitoring • GPS Controlled • Automatic Pipe‐to‐Soil Potential Reads • Automatic Rectifier Voltage & Amperage Reads • Alarm Notification • Interruption Capabilities • Cellular, Satellite & Radio Communication Circuit Interruption • Rectifiers & Foreign Bonds • Sacrificial Anodes • GPS Controlled • Programmable Schedule Fault Protection & Grounding • Solid State • Induced AC Voltage Mitigation • Stray DC Voltage Blocking • Insulated Joint Protection Ultrasonic Thickness (UT) Gauges Thermite Welding Over‐the‐Line Survey Techniques Over‐the‐Line Survey Techniques ¾Close Interval Survey (CIS) • Cathodic Protection Potential Profile ¾Pipeline Current Mapping (PCM) • Maps Cathodic Protection Current Loss due to Coating Failure or Shorted conditions ¾Direct Current Voltage Gradient (DCVG) ¾Alternating Current Voltage Gradient (ACVG) • Pinpoints Coating Defects .
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