UNITED STATES DEPARTMENT OF AGRICULTURE

NATURAL RESOURCES CONSERVATION SERVICE

OREGON

[CONSTRUCTION SPECIFICATION]{.underline}

[CS-51 CATHODIC PROTECTION]{.underline}

51.1 [SCOPE]{.underline}

> The work shall consist of furnishing and installing all materials
> necessary to provide cathodic protection to metal pipelines, tanks,
> structures and other buried ferrous metal structures. Only prepackaged
> anodes without induced current shall be provided under this
> specification.

51.2 [MATERIALS]{.underline}

> a\. [Anodes]{.underline}
>
> The anodes shall be of the type and size specified. They shall be
> commercially cast and pre-packaged. Each anode shall have a full
> length core with a #12 AWG or larger insulated copper lead wire
> attached.
>
> Zinc anodes shall conform to the requirements of ASTM B-418, Type II
> composition. Unless otherwise specified, the packaged backfill shall
> be 20-30 percent bentonite and 70-80 percent gypsum.
>
> Magnesium anodes shall have a chemical composition of 5-7 percent
> aluminum, 2-4 percent zinc, 0.15-0.25 percent manganese, a maximum of
> 0.7 percent other varied elements, and the balance magnesium. The
> packaged backfill shall be approximately 75 percent hydrated gypsum,
> 20 percent bentonite, and 5 percent sodium sulfate.
>
> b\. [Wire]{.underline}
>
> The wire for header cables, anode leads, and joint bridging shall be a
> single conductor, standard, plain annealed copper with a black,
> high-molecular weight polyethylene insulation and jacket. The
> polyethylene shall conform to ASTM Designation D-1248, Type I, Class
> C, Grade 5.
>
> Wire for header cables and anode leads shall be 12 AWG copper or
> larger. Wire for bridging joints shall be 6 AWG copper or larger.
>
> c\. [Powder Weld Process]{.underline}
>
> The welder and powder charge shall be of the size, type and
> composition recommended by the manufacturer for permanently fastening
> copper wire to copper wire or to steel or cast iron surfaces. The
> resulting weld shall be a permanent, low resistance copper connection.
>
> d\. [Silver Solder Process]{.underline}
>
> The silver solder process shall be for very low voltage electrical
> connections. Manufacturer's instructions shall be followed.

51.3 [INSTALLING ANODES]{.underline}

> Anodes shall be placed as shown on the drawings. They may be placed
> either horizontally or vertically and shall be deep enough to have at
> least three (3) feet of earth cover. Anodes shall not be placed in
> fill areas. Magnesium anodes shall be placed a minimum distance of 10
> feet from the pipeline or structure.
>
> Anodes shall be bedded in moist fine grained soils such as CH, CL, MH,
> or ML. In sandy and gravely areas, fine materials must be imported for
> bedding and for covering the anodes to a depth of approximately 6
> inches. The packaged anodes and the fine textured soils used for
> bedding and backfill shall be thoroughly wetted. Compaction of the
> backfill around anodes shall be the density of the surrounding
> material.
>
> If the anode cannot be placed in a low or wet location, sand or gravel
> shall be used as backfill above the fine grained fill around and over
> the anode. The location of the anode shall be at least 6 inches lower
> and shaped to direct runoff to the anode.

51.4 [ATTACHING THE ANODE]{.underline}

> Unless otherwise specified, the lead wire from the anode, or from the
> header wire for multiple anode installations, shall be attached to the
> pipeline or structure by a powder welding process. In the area of the
> damaged pipe or structure coating the metal and the weld shall be
> covered with a coating equal in quality to the original of the metal.
>
> Unless otherwise specified, the lead wires from anodes shall be
> connected to the header wire by a powder weld, brazed, or silver
> soldered. The connection shall be thoroughly cleaned and wrapped with
> vinyl electrical tape.

51.5 TESTING STATIONS

> Testing stations shall be located and installed as specified on the
> drawings. All connections shall be as specified and shall be
> electrically insulated.

6.  [ITEMS OF WORK AND CONSTRUCTION DETAILS FOR THIS
    PROJECT]{.underline}