VA 26 42 00-2009 CATHODIC PROTECTION.pdf

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1、4-09 26 42 00 - 1 SECTION 26 42 00 CATHODIC PROTECTION SPEC WRITER NOTES: 1. Utilize this spec for underground steel oil tanks and oil piping only when the soil resistivity is less than 4000 ohm-cm. Otherwise, the cathodic protection of oil tanks and oil piping is covered by Section 23 10 00, FACILI

2、TY FUEL SYSTEMS. 2. References to pressure in this section are gage pressure unless otherwise noted. 3. The U.S. Department of Transportation has issued regulations requiring the application of cathodic protection to flammable gas and liquid pipelines and storage facilities. Title 49 of the SECTION

3、26 42 14.00 10 Page 4 Code of Federal Regulations, Parts 191, 192, 193 and 195 should be consulted for applicable cathodic protection requirements for specific applications. PART 1 GENERAL 1.1 DESCRIPTION A. This section specifies complete galvanic sacrificial anode type cathodic protection systems

4、for underground steel structures. The section also includes devices to electrically isolate the system being protected. B. The services required include planning, installation, adjusting and testing of a cathodic protection system, using sacrificial anodes for cathodic protection of the /Water/ /Fir

5、e Protection/ /Force Main/ /Gas/ / / lines, their connectors and /lines under the slab or floor foundation./ The cathodic protection system shall include anodes, cables, connectors, corrosion protection test stations, and any other equipment required for a complete operating system providing the NAC

6、E criteria of protection as specified. Insulators are required whenever needed to insulate the pipes from any other structure. Any pipe crossing the / / pipe shall have a test station. 1.2 RELATED WORK A. Section 03 30 00, CAST-IN-PLACE CONCRETE. B. Section 23 05 11, COMMON WORK RESULTS FOR HVAC AND

7、 STEAM GENERATION. C. Section 23 10 00, FACILITY FUEL SYSTEMS: Coating on underground steel oil tanks, secondary containment of underground tanks and piping systems. D. Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS: General electrical requirements that are common to more than one secti

8、on of Division 26. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4-09 26 42 00 - 2 SPEC WRITER NOTE. Bonding grounding electrodes of the electrical system ground and the lightning protection system to buried steel sets up a galvanic cell that corro

9、des that steel. Coordinate cathodic protection with the following two specification sections. E. Section 26 05 06, GROUNDING AND BONDING FOR ELECTRICAL SYSTEMS: Requirements for personnel safety and to provide a low impedance path to ground for possible ground faults. F. Section 26 41 00 FACILITY LI

10、GHTNING PROTECTION: Requirements for personnel safety and to provide a low impedance path to ground for lightning caused surges. G. Section 33 63 00, STEAM ENERGY DISTRIBUTION: Coating on underground steel casings for steam distribution systems. 1.3 QUALITY ASSURANCE A. Refer to Paragraph, QUALIFICA

11、TIONS, in Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS. B. The Contractor shall be regularly engaged in the installation and testing of cathodic protection systems. Contractors personnel shall be experienced and shall be supervised by an engineer who is accredited as a Corrosion Speci

12、alist or Corrosion Protection Specialist by the National Association of Corrosion Engineers (NACE) International. All calculations, design and testing shall be performed by or supervised by the Corrosion Specialist or Engineer. All procedures shall conform to recommendations of NACE RP0169 unless sp

13、ecified otherwise. 1.4 SUBMITTALS A. Submit in accordance with Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND SAMPLES. B. Design Submittal: For cathodic protection system indicated to comply with performance requirements and design criteria, including analysis data signed and sealed by the quali

14、fied corrosion engineer responsible for their preparation. 1. Conduct site tests necessary for design, including soil resistivity, close-interval potential surveys, testing during construction, interference testing, and training of Owners personnel. 2. Provide system design calculations, stating the

15、 maximum recommended anode current output density, and the rate of gaseous production, if any, at that current density. C. Furnish catalog cuts and shop drawings of following items: 1. Anodes. 2. Cable and wire. Provided by IHSNot for ResaleNo reproduction or networking permitted without license fro

16、m IHS-,-,-4-09 26 42 00 - 3 3. Test stations. 4. Terminal boxes. 5. Isolating flanges, unions, coatings, casing seals. 6. Exothermic welding devices. 7. Cable splice kits. 8. Layout drawings, wiring diagrams. 9. Test instruments. 10. Dielectric tape. 11. Test connection points. D. Detail drawings co

17、nsisting of a complete list of equipment and material including manufacturers descriptive and technical literature, catalog cuts, results of system design calculations including soil-resistivity, installation instructions and certified test data stating the maximum recommended anode current output d

18、ensity and the rate of gaseous production if any at that current density. Detail drawings shall contain complete wiring and schematic diagrams and any other details required to demonstrate that the system has been coordinated and will function properly as a unit. E. Accreditation of Corrosion Specia

19、lists or Engineers by NACE International. F. Test reports in booklet form tabulating all field tests and measurements performed, upon completion and testing of the installed system and including close interval potential survey, casing and interference tests, final system test verifying protection, i

20、nsulated joint and bond tests, and holiday coating test. A certified test report showing that the connecting method has passed a 120-day laboratory test without failure at the place of connection, wherein the anode is subjected to maximum recommended current output while immersed in a three percent

21、sodium chloride solution. G. Operation and Maintenance Manual: Include the following: 1. Basic system operation, outlining the step-by-step procedures required for system startup, operation, adjustment of current flow, and shutdown. 2. Instructions for pipe-to-reference cell and tank-to-reference ce

22、ll potential measurements and frequency of monitoring. 3. Instructions for dielectric connections, interference and sacrificial-anode bonds; and precautions to ensure safe conditions during repair of pipe, tank or other metallic systems. Instructions shall be neatly bound. 4. Locations of all anodes

23、, test stations, and insulating joints. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4-09 26 42 00 - 4 5. Structure-to-reference cell potentials as measured during the tests required by “Field Quality Control“ Article. 6. Recommendations for maint

24、enance testing, including instructions for pipe-to-reference cell potential measurements and frequency of testing. 7. Precautions to ensure safe conditions during repair of pipe system. H. Certifications: 1. Two weeks prior to final inspection, submit four copies of the following to the Resident Eng

25、ineer: a. Certification by the Contractor that the cathodic protection system has been properly installed, adjusted and tested. b. Certified copies of all of the factory design and production tests, field test data sheets and reports for the assemblies. 1.5 APPLICABLE PUBLICATIONS A. The publication

26、s listed below form a part of this specification to the extent referenced. The publications are referenced in the text by basic designation only. B. American Society for Testing and Materials (ASTM): B8-04 Concentric-Lay-Stranded Copper Conductors, Hard, Medium Hard, or Soft D1248-05 . Polyethylene

27、Plastic Extrusion Materials for Wire and Cable ASTM F 1182 Anodes, Sacrificial Zinc Alloy G57-06 . Field Measurement of Soil Resistivity Using the Wenner Four-Electrode Method C. American Society of Mechanical Engineers (ASME): B16.5-03 . Pipe Flanges and Flanged Fittings: NPS through 24 D. National

28、 Association of Corrosion Engineers (NACE) International : RP0169-02 Control of External Corrosion on Underground or Submerged Metallic Piping Systems RP0285Corrosion Control of Underground Storage Tank Systems by Cathodic Protection PART 2 - PRODUCTS 2.1 ANODES A. Type: Magnesium, factory-packed in

29、 cloth bag or box containing prepared backfill mixture, with lead wires. B. Construction: 1. Alloy Specifications: SPEC WRITER NOTE: The chemical composition listed is for high potential anodes in Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4-09

30、26 42 00 - 5 accordance with ASTM B 843. Should standard magnesium anodes be considered suitable, provide appropriate chemical composition. Specify chemical composition which will provide adequate and economical service. Element Percent-(Option-1) Percent-(Option-2) Aluminum 5.0 - 7.0 0.010 Max. Man

31、ganese 0.15 Min. 0.50 - 1.30 Zinc 2.0 - 4.0 0.05 Max. Silicon 0.30 Max. 0.05 Max. Copper 0.10 Max. 0.02 Max. Nickel 0.003 Max. 0.001 Max. Iron 0.003 Max. 0.03 Max. Other 0.30 Max. 0.30 Max. Magnesium Remainder Remainder 2. Core: Perforated galvanized steel, maximum 0.10-pounds per linear foot 0.148

32、kg per meter, one end accessible in a recess for lead wire connection. 3. Lead Wire: Number 12 solid copper, 10 feet 3m long, Type HMWPE (high molecular weight polyethylene) insulation, ASTM D1248, Type 1, Class C, Category 5, Grade E5. 4. Lead Wire Attachment to Core: Anode lead wire shall be facto

33、ry installed. /Silver solder the lead wire to the anode core, and seal the soldered connection and recessed end of the anode with an /asphaltic/ /epoxy/ dielectric sealing compound./ /Silver solder the wire to the protruding anode core, and completely seal the soldered connection with an /asphaltic/

34、 /epoxy/ dielectric material./ Dielectric material shall extend past the connection and cover the lead wire insulation by not less than 1/2 inch 15mm. /Cover the connection with heat shrinkable tubing./ 5. Packaging: Permeable cloth bag or box with backfill mixture completely surrounding anode 1/2 i

35、nch 15mm minimum. a. Grain Size: Pass through 20-mesh screen - 100 percent; retained by 100-mesh screen - 50 percent. b. Components: Ground Hydrated Gypsum 75 percent Powdered Wyoming Bentonite 20 percent Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,

36、-,-4-09 26 42 00 - 6 Anhydrous Sodium Sulphate 5 percent c. Weight: Weight requirements are listed on the drawings. Listings refer to alloy weight only. d. Center the anode in the firmly packed backfill using spacers. Overall dimensions of the bagged /17/ /32/ / / pound /7.72/ /14.53/ / / kg anode s

37、hall be /6.5 by 17 inches/ /8 by 21 inches/ / by inches/ /165 by 432 mm/ /203 by 535 mm/ with a total minimum weight of /45/ /74/ / / pounds /20.4/ /33.6/ / /kg nominal. 2.2 INSULATED CABLE A. Type: One conductor, stranded, annealed copper, Type HMWPE (high molecular weight polyethylene) insulation

38、and jacket. B. Service: Buried in corrosive soils. Header cable, test leads, bonding cable. C. Construction: 1. Table: MINIMUM THICKNESS OF INSULATION AND JACKET AWG-SIZE NUMBER-OF-STRANDS inches mm No. 8 7 7/64 2.8 No. 6 7 7/64 2.8 No. 4 7 7/64 2.8 No. 2 7 7/64 2.8 No. 1 19 8/64 3.2 No. 1/10 19 8/6

39、4 3.2 2. Insulation: ASTM D1248, Type 1, Class C, Category 5, Grade E5. 3. Conductors: ASTM B8. D. Lead wires terminating at a junction box or test station shall have a cable identification tag. 2.3 CABLE CONNECTIONS A. Type: Connections between cables and pipes, casings or structures shall be exoth

40、ermic fusion-welding process using copper oxide, aluminum and vanadium welding material in graphite molds. Connections between cables and between cables and leads shall be corrosion-resistant split bolts. B. Insulation of Cable-to-Cable Connections: Epoxy-resin splice kits with two-part resin, mold,

41、 sealing mastic. C. Coating of Cable Connections to Protected Structures: Field-applied coating similar to that on the protected structure. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4-09 26 42 00 - 7 2.4 CABLE AND WIRE IDENTIFICATION TAGS /Lami

42、nated plastic material with black letters on a yellow background/ /Brass/ /Stainless steel/ material with engraved letters/. Print letters and numbers a minimum of 3/16 inch 5mm in size. Provide identifier legend in accordance with the drawings. 2.5 TEST STATIONS A. Type: Weatherproof, located at gr

43、ade, or aboveground if so shown. Enclosed terminals for anode leads, test leads, and leads attached to protected system. Connection points for test instruments. B. Construction: 1. Housing: The unit shall be of standard design, manufactured for use as a cathodic protection test station, complete wit

44、h locking cover, terminal board, shunts, and brass or Type /304/ /316/ stainless steel hardware. The terminal board shall be removable for easy access to wires. High-impact resistant plastic. Provide means to anchor housing below grade. Yellow color. 2. Terminal Board: High-impact resistant plastic

45、board, cadmium or zinc-plated hardware, accessible from front and rear, sufficient terminals for all required connections. 3. Provide terminal boards for anode junction boxes, bonding boxes, and test stations made of phenolic plastic /1/8/ /1/4/ / / inch /3/ /6/ / / mm thick with dimensions as indic

46、ated. Insulated terminal boards shall have the required number of terminals (one terminal required for each conductor). Install solderless copper lugs and copper buss bars, shunts, and variable resistors on the terminal board as indicated. Test station terminal connections shall be permanently tagge

47、d to identify each termination of conductors (e.g. identify the conductors connected to the protected structure, anodes, and reference electrodes). Conductors shall be permanently identified by means of plastic or metal tags, or plastic sleeves to indicate termination. /Each conductor shall be color

48、 coded as follows: Anode lead wire - black Structure lead wire white Reference electrode lead wire - red/ 2.6 PERMANENT REFERENCE ELECTRODES Permanent reference electrodes shall be /copper copper-sulfate/ /silver silver-chloride/ /zinc/ specifically manufactured for underground use, /1 1/4/ / / inch /32/ / / mm diameter, by /10/ / / inches /255/ / / mm long, /plastic / / tube with an ion trap to minimize contamination of the cell, and a minimum surface sensing area of / / square inches/ / square Provided by IHSNot for ResaleNo reproduction or netwo