Tm merl 2012 40 cathodic protection field installation guide accessible

Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems U.S Department of the Interior Bureau of Reclamation December 2012 Mission Statements The U.S Department of the Interior protects America’s natural resources and heritage, honors our cultures and tribal communities, and supplies the energy to power our future The mission of the Bureau of Reclamation is to manage, develop, and protect water and related resources in an environmentally and economically sound manner in the interest of the American public Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems U.S Department of the Interior Bureau of Reclamation December 2012 BUREAU OF RECLAMATION Technical Service Center, Denver, Colorado Materials Engineering and Research Lab Group, 86-68180 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems 8/2 r Daryl A Little Mfed: " Materials Engineer, Materials Engineering and Research Lab Group, 86-68180 Date Z- Che1648: Jessica D Tor� Materials Engineer, Mats Engineering and Research Lab Group, 86-68180 Date � Editorial Approval: Teri Manross Technical Writer-E 'tor, Client Support and Technical Presentations Office, 86-68010 Date Technic� oval: Lee E Sears� Material ngineer, Materials Engineering and Research Lab Group, 86-68180 Date Peer Review: William F Kepler, P.E Civil Engineer, Materials Engineering and Research Lab Group, 86-68180 Date ( ///7 � - Peer Review Technical Approval Description Checked Date Prepared REVISIONS Contents Page Chapter I: Introduction   Corrosion Monitoring and Cathodic Protection Systems 1  Terminology 1  Role of Contracting Officer’s Representative 3  Reference Standards   ASTM International 3  Bureau of Reclamation   National Electrical Manufacturer’s Association   Chapter II: Components 5  Common System Components 5  Cable   Metallurgical Welds and Bitumastic Material 6  Test Stations 7  Anode Junction Boxes 8  Shunts 8  Variable Resistors 9  Protective Barriers 10   Permanent Reference Electrodes 10  Insulated Joint Flange Kit 12  Casing Isolation Devices 14   Dielectric Barrier Material 15  Warning Tape 15  Sand 16  Conduit 16  Galvanic Anode Systems 16   Anodes 16  Buried 16  Submerged 17  Impressed Current Systems 18   Anodes 18  Buried 18  Submerged 19  Rectifiers 20  Pea Gravel 21  Vent Pipe 21  Carbonaceous Backfill 22  Anode Centralizing Devices 24  Grounding Rod and Cable 24   Rectifier Protective Barriers 24  i Contents (continued) Page Chapter III: Installation 25  General Installation 25   Cable 25   Inspection for Quality Control 25   Exothermic Metallurgical Bonds 25  Electrical Continuity Joint (Jumper) Bonds 27  Structure Cables 29  Buried Applications 29  Cable Identification 30  Electrical Isolation (Insulation) 31   General 31  Isolation Joint Flange Kit 31  Installation 31  Testing 33  Casing Isolation 34   Installation 34  Testing 36  Test Stations and Junction Boxes 36  Locations 36   Corrosion Monitoring 37   Isolation Joints 39  Casings 41  Foreign Line Crossings 44   Galvanic Anode(s) 46  Barriers 50  Triangular Barriers 50   Rectangular Barriers 50   Galvanic Anode Systems 53   Buried Anodes 53   Submerged Anodes 53  General 53   Suspended 53   Surface Mounted 57  Impressed Current Systems 58   Rectifiers 58  Anode Junction Boxes 58   Buried 59  Shallow Bed 59   Deepwell Bed 60   Submerged 64  Wire Anodes 64   Flush Mounted 66   ii Contents (continued) Page Permanent Reference Electrodes 68  Buried 68  Submerged 69  Through-wall 69   Surface Mounted 70 Chapter 4: Startup and Testing .71   Procedures 71   Safety 71  Test Equipment 72   Testing 74  Pre-energizing 74  Energizing and Testing Systems 75  First Test Cycle 75   Second and Subsequent Testing Cycles 76 Appendix: Galvanic CP System Checklist and Impressed Current CP System Checklist Figures Page Stranded copper cable with HMWPE insulation (left) and a combination of HMWPE and Halar insulation (right) for chloride environments Metallurgical weld and bitumastic materials for attaching cables to structure Big Fink type test station showing the components: (a) cap, test board, and PVC post; and (b) and (c) completed test stations Anode junction boxes with individual shunts and variable resistors Rectifier shunt for determining current output Shunt has a rating of 50 amperes/50 millivolts Various types of available anode shunts: (a) Cott shunts are color coded for rating, with ratings of 0.1 ohm (red), 0.01 ohm (yellow), and 0.001 ohm (orange) Variable resistors for controlling galvanic and impressed current anode output: (a) slide resistor, and (b) and (c) dial type resistors 10 (a) Buried copper/copper sulfate, permanent reference electrode schematic, and (b) finished product .12 (a) Through-wall, and (b) wall attached submerged permanent reference electrodes .12 iii Figures (continued) Page 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 iv Schematic of type E isolation flange kit, showing the various components for two-sided isolation .13 Schematic of type F isolation flange kit, showing the various components for single-sided isolation 14 Casing isolation kit for metallic pipelines 15 Warning tape used for marking location of CP cables 15 Conduit for mounting submerged anodes such as rod and wire anodes 16 Bare and bagged galvanic anodes 17 Galvanic anodes for use on submerged structures .18 (a) Graphite impressed current anode, and (b) HSCI impressed current anode 19 Linear anode of conductive-polymer coated copper, surrounded by high conductivity coke breeze, and held in place by a porous, woven, acid-resistant jacket .19 Examples of impressed current anodes include: (a) disk, (b) wire, pencil, and mesh; (c) stick or rod; and (d) through-wall probe electrodes .20 Rectifiers used for impressed current CP systems, showing: (a) galvanized enclosure, and (b) manual taps for adjusting the voltage 21 (a) Vent pipe with vertical and transverse slots for deep well anode beds, and (b) circled area blown up to show vertical slot cut in the pipe .22 (a) Bag of petroleum coke backfill used for impressed current anode beds, and (b) spherical grained petroleum coke structure 23 Example of device for centering anodes in deep well anode beds 24 Schematic diagrams show the proper procedure for metallurgically bonding cables to metallic structures 26 Schematic shows jumper bond installation for: (a) a flanged joint (nonisolating), (b) a push-on joint, and (c) a flexible coupling (multiple component coupling) .28 Schematic shows jumper bond installation for Victaulic joints .28 Schematic shows jumper bond installation for PVC to steel fitting .28 Examples of jumper bonds for various pipe situations: (a) The mortar coating was removed at the joint to attach the jumper bond; (b) jumpers were installed on the pipe across the various joints, and the weld nuggets were covered with bitumastic molded cap (Handy Cap) prior to burial; and (c) bonds were installed across the expansion joint on an outlet works pipe, and the weld nuggets were coated with a bitumastic coating 29 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems a) b) Figure 52 (a) Example of an anode centralizer for deep well anodes, and (b) with anode and vent pipe attached for installation Submerged Wire Anodes Anode mounting and assembly in accordance with following: Mounted inside perforated nonmetallic anode protector pipes mounted to the sump structure walls as shown in figure 53a and b Protector pipe attached to wall using plastic ties (figure 53b) or hose clamps, or stainless steel anchors The half of the anode protector pipe adjacent to the sump wall should not be perforated (figure 53b) Dielectric coating applied to the structure wall behind and adjacent to the anodes so that the dielectric coating extends a minimum of 1-1/2 feet on all sides of the anode protector pipe (figure 53) Cables in accordance with cable sections and protected by PVC or galvanized pipe conduit above the water line between anode and anode junction box 64 Chapter III Installation a) b) Figure 53 (a) Slotted pipe mounted on sump wall for wire anode installation, and (b) close-up of the slots in the pipe and the wall attachment details The black sheet is a dielectric material to shield the reinforcement steel in the concrete from the impressed current 65 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems Flush Mounted Anode mounting and assembly in accordance with figure 54 and described as follows: Hole drilled in structure (e.g., gate skinplate) for the disk anode Portion of structure surface that will contact the fiber reinforced polymer (FRP) anode shield should be cleaned without damaging the coating Back surface (side placed against structure) of the FRP anode shield roughened and cleaned Polyurethane sealer applied to the back surface of the FRP anode shield: a A continuous bead formed approximately inch from the outside edge of the FRP anode shield and approximately inch from the FRP mounting stud b Between these two beads, continuous beads applied in a crosshatch pattern at approximately 2-inch centers Anode stud inserted into drilled hole from the upstream or water side and fastened using the FRP washer and nut on the downstream or dry side a Dry side refers to either atmospheric only or soil Tighten the nut to the torque recommended by the disk anode manufacturer Displaced polyurethane sealer smoothed between the periphery of the anode shield and structure, and any excess polyurethane sealer removed Compression fitting, junction box, nuts, and washers on the titanium anode shaft installed The COR should approve the routing of the installed conduit system and location of the installed junction boxes prior to installation Figure 55 shows a finished disk anode assembly The red arrow in figure 55a shows the anode on the upstream side of the gate Figure 55b shows the downstream side (dry side) of the disk anode assembly 66 Figure 54 Schematic of flush-mounted, disk mixed metal oxide anode showing front view (left side) and profile assembly Chapter III Installation 67 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems a) b) Figure 55 Flush mounted impressed current disk anodes: (a) arrow indicates the location of a disk anode on the upstream side of a radial gate; (b) downstream side of the gate showing the finished anode installation Permanent Reference Electrodes Buried Permanent reference electrodes are buried in accordance with manufacturer’s instructions and as follows: See specification for permanent reference electrode location Bagged electrode removed from plastic shipping bag or carton Record the serial number and quality control test potential; these are located on the yellow tag attached to the lead wire Calibration testing: a Option 1: Prior to installation, the prepackaged reference electrode is soaked in a container of potable water for 30 minutes: i Measure potential difference between the permanent reference electrode and an independent (portable) calibrated reference electrode placed in the water adjacent to the permanent reference electrode ii Permanent reference electrodes not within a 10- to 15-mV potential difference should be removed and replaced at the contractor's expense b Option 2: Electrode placed into borehole or excavation oriented vertically or horizontally 68 Chapter III Installation i Sift fine backfill into the borehole Fill to about inches (5 centimeters) above top of bag ii For excavation, pile the soil to form a berm around the electrode The berm should be approximately inches (15 centimeters) higher than the top of the bag and completely surround it iii Saturate the bag by slowly pouring approximately gallons (20 liters) of water onto the bag iv Measure potential difference between the permanent reference electrode and an independent (portable) calibrated reference electrode placed as close as possible to the bag of the permanent reference v Permanent reference electrodes not within a 10- to 15-mV potential difference should be removed and replaced at the contractor's expense Fill the hole or excavation with normal backfill only after permanent reference electrodes have been tested and approved by COR Do not lift the electrode by pulling the lead wire Do not allow to freeze, install below frost line, and keep dry prior to installation Reference electrode lead wire and pipe test lead wire should be connected to separate terminals in test station Submerged Through-Wall Permanent reference electrodes are installed in accordance with manufacturer’s instructions and as follows: Electrode installed through threaded port in wall of structure Locate electrode below minimum water elevation Electrode cable run through separate galvanized conduit from the anode cables to the junction box Electrode cable terminated in junction box 69 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems Surface Mounted Permanent reference electrodes are installed in accordance with manufacturer’s instructions and as follows: Electrode installed inside structure, securely attaching to the wall, so that it is removable without damaging the electrode Electrode cable protected from damage inside structure Electrode cable run through separate galvanized conduit from the anode cables to the junction box Electrode cable terminated in junction box 70 Chapter IV Startup and Testing Procedures Includes energizing, adjusting, and testing the CP systems Performed in the presence of COR COR informed of the date, time, and tests to be performed at least working days prior to testing Safety Safety issues involved with CP systems include, but are not limited to: Environmental issues including heat, cold, rain, and lightening: a Do not test electrical equipment when it is raining Insects and other pests including snakes, wasps, and spiders: a Watch where you step b Open junction boxes, test stations, and rectifiers with care Rectifiers have safety concerns from both AC and DC voltages: a Approach a rectifier carefully b Check for grounding using an AC voltmeter or AC voltage proximity detector: i Do not grab the latch or handle on the rectifier without checking for an AC short If necessary, touch the cabinet with the back of your hand If the casing is shorted and you touch it with the back of your hand, you can remove your hand However, if you grab it and your hand closes, you cannot let go potentially resulting in serious injury c All work performed on the rectifier should take place with the power off at both the rectifier and an external circuit breaker d If possible, only work with one hand in the rectifier cabinet at a time to avoid creating a circuit through your body 71 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems e Table shows the physiological effects of 60-hertz AC Shock hazards and shorting are possible within the impressed current anode junction boxes if the box is too small for easy access to all the cables and resistors Table Physiological Effects of 60-Hertz AC Current (mA) Physiological Effect 200 Severe burns Test Equipment Portable voltmeter: a High impedance digital multimeter: Fluke Model 27 (figure 56a), manufactured by Fluke Corporation, 6920 Seaway Boulevard, Everett, WA 98203; or equal, having the following essential characteristics: i Minimum input impedance of 10 megohms ii Capable of measuring DC voltages between ±0.1 mV to ±1,000 volts b Selectable input resistance digital multimeter: MCM LC-4 (figure 56b), manufactured by M.C Miller Co., Inc., 11640 U.S Highway 1, Sebastian, FL 32958; or equal, having the following essential characteristics: i Selectable input resistance 0-200 ohms (0.1-ohm resolution) ii Selectable DC voltage range 0-200 volts (0.01-mV resolution) 72 Chapter IV Startup and Testing Portable copper/copper sulfate (Cu/CuSO4) reference electrode as shown in figure 57 Meter for determining resistivity of soil around anode (figure 58) a) b) Figure 56 Multimeters for measuring potentials associated with CP systems: (a) Fluke 27 digital multimeter, and (b) MC Miller LC-4 variable resistance input digital multimeter Plastic case Copper rod Porous plug Saturated copper sulfate Cap Figure 57 Copper/copper sulfate portable reference electrode for determining structure-to-electrolyte and anode-to-electrolyte potentials The various components of the electrode are labeled to include plastic case, copper rod, porous plug, saturated copper sulfate, and cap 73 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems Figure 58 Meter for determining resistivity of soil around anodes Testing Pre-energizing Structure electrical continuity Test station integrity: a Voltage difference between the cables Static anode-to-electrolyte potentials: a At anode location for impressed current system b At each test station enclosure for galvanic anodes Static structure-to-soil potentials of the buried metalwork: a At each individual test station location b Portable reference electrode placed as close to the buried metalwork as possible Static structure-to-water potentials of the submerged metalwork: a At each individual structure location b Portable submersible reference electrode placed as close to the submerged metalwork as possible 74 Chapter IV Startup and Testing Energizing and Testing Systems First Test Cycle Galvanic Anode Systems Anode cables connected through individual shunt and variable resistors (if necessary) to No AWG or larger structure cable in test station or junction box Protective (uncorrected) and polarized structure-to-electrolyte potentials: a Buried: i At each individual test station location ii Portable reference electrode placed as close to the buried metalwork as possible b Submerged: i At each individual structure location ii Portable submersible reference electrode placed as close to the submerged metalwork as possible Current output of each individual anode in junction box Variable resistor setting for each anode and structure Impressed Current Systems Cable connection to rectifier: a Structure cable must be connected to the NEGATIVE DC output terminal b Anode cable must be connected to the POSITIVE DC output terminal Protective (uncorrected) and polarized structure-to-electrolyte potentials: a Buried: i At each individual test station location ii Portable reference electrode placed as close to the buried metalwork as possible 75 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems b Submerged: i At each individual structure location ii Portable submersible reference electrode placed as close to the submerged metalwork as possible Current output of each individual anode in junction box Variable resistor setting for each anode and structure Rectifier outputs in volts and amperes and associated tap settings Second and Subsequent Testing Cycles Time between testing cycles is 30 to 60 days Cathodic protection system not adjusted between testing cycles All testing during the first testing cycle repeated If testing cycle data indicates that the CP system requires adjustment to meet specifications requirements, CP system adjusted and subsequent testing cycle conducted within a 30- to 60-day window 76 Appendix Galvanic CP System Checklist ഼ Item (required) ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ anodes cables - anode (galvanic) cables - structure (pipe) cables - test cables - bond exothermic weld supplies joint bond supplies test station "CP" warning tape Item (system dependent) ഼ junction box permanent reference electrode permanent reference electrode cable cable - foreign structure - bond cable - foreign structure - test cable - casing structure - bond cable - casing structure - test ഼ ഼ ഼ ഼ ഼ ഼ Item (misc) ഼ ഼ test station barrier concrete for test station Appendix-1 Technical Memorandum No MERL-2012-40 Guidelines for Field Installation of Corrosion Monitoring and Cathodic Protection Systems Impressed Current CP System Checklist Item (required) ഼ rectifier junction box circuit breaker box anodes vent pipe, caps, u-joint coke backfill cables - anode (IC) cables - structure (pipe) cables - test cables - bond grounding rod and cable exothermic weld supplies joint bond supplies test station "CP" warning tape ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ ഼ Item (system dependent) ഼ permanent reference electrode permanent reference electrode cable cable - foreign structure - bond cable - foreign structure - test cable - casing structure - bond cable - casing structure - test ഼ ഼ ഼ ഼ ഼ Item (misc) ഼ ഼ ഼ ഼ Appendix-2 sand & pea gravel backfill conduit for anode cables test station barrier concrete for test station & rectifier post