Natural Resources Conservation Service

Conservation Practice CONSTRUCTION Specification

Irrigation Water Conveyance - STEEL Pipeline

Code 430FF

1.  SCOPE

> The work shall consist of furnishing and installing steel pipe
> complete with lining, coating, fittings, and appurtenances as shown on
> the drawings.

## SITE PREPARATION

Site preparation (mobilization and demobilization, clearing and
grubbing, structure removal, pollution control, and water for
construction) shall be in accordance with Construction Specification
587.

## MATERIALS

a.  **Pipe**

> Steel pipe shall conform to the requirements of the applicable
> specification listed below for the kind of pipe and the type, weight,
> grade, and finish specified:
>
> [Pipe]{.underline} [ASTM Specification]{.underline}
>
> Steel, black and hot-dipped, zinc-coated welded and seamless A 53
>
> Steel, electric-fusion (ARC)-welded (sizes NPS 16 and over) A 134
>
> Electric-resistance-welded steel A 135
>
> Electric-fusion (ARC)-welded steel (NPS 4 and over) A 139
>
> [Pipe]{.underline} [AWWA Standard]{.underline}
>
> Steel water pipe, 6 inches and larger C 200

b.  **Coatings and Lining**

> Coating and lining materials shall conform to the requirements of the
> following:
>
> • AWWA C203, Standard for Coal-Tar Protective Coatings and Linings for
> Steel Water Pipelines - Enamel and Tape - Hot-Applied
>
> • AWWA C209, Standard for Cold-Applied Tape Coatings for the Exterior
> of Special Sections, Connections, and Fittings for Steel Water
> Pipelines
>
> • AWWA C214, Standard for Tape Coating Systems for the Exterior of
> Steel Water Pipelines
>
> and as specified below:
>
> • Shop coating material shall conform to the requirements of AWWA
> Standard C203 and AWWA Standard C214 and as specified in section 12 of
> this specification.
>
> • Shop lining material shall conform to the requirements of AWWA
> Standard C203.
>
> • Field coating and coating repair material shall conform to the
> requirements of AWWA Standard C203, AWWA Standard C209, AWWA Standard
> C214, and, as specified in Section 12 of this specification.
>
> • Field lining material shall conform to the requirements of AWWA
> Standard C203 and as specified in section 12 of this specification.

c.  **Anodes**

> Zinc anodes shall meet or exceed the requirements of ASTM
> Specification B 418 (Standard Specification for Cast and Wrought
> Galvanic Zinc Anodes). Each anode shall have a solidly attached full
> length core with a single strand of insulated copper wire. The wire
> shall be No. 12 or larger. If a header wire is used, the gage shall be
> adequate to catty the design current with no more than a 20 mV I-R
> drop. All anodes shall be commercially packaged.

d.  **Welding Electrodes**

> Steel welding electrodes shall conform to the requirements of American
> Welding Society Specification AWS A5.1, \"Specification for Mild Steel
> Covered Arc-Welding Electrodes,\" except that they shall be uniformly
> and heavily coated (not washed) and shall be of such a nature that the
> coating does not chip or peel while being used with the maximum
> amperage specified by the manufacturer.

e.  **Appurtenances**

> Unless otherwise specified or as may be shown on the drawings,
> standard fittings, special fittings and appurtenances shall be of the
> same material as the pipe. Steel supports and saddles shall be
> constructed of material that equals or exceeds the requirements
> specified in ASTM A 36.

## FOUNDATION WORK

> Foundation work (diverting surface water, dewatering the construction
> site, dewatering borrow areas, and foundation preparation) shall be in
> accordance with Construction Specification 587.

## EARTHWORK

> Earthwork (common excavation and earthfill) shall be in accordance
> with Construction Specification 587.

## JOINTS AND CONNECTIONS

> Pipe joints shall conform to the details shown on the drawings and
> shall be sound and watertight at the pressures specified in this
> specification or as may be shown on the drawings.

a.  **Welded Joints**

> Welding and welded joints shall conform to the welding procedure
> details and requirements of AWWA Standard C206. Field welding shall be
> done in such a way as to avoid burning the protective coating on the
> pipe except in the immediate vicinity of the weld.
>
> Where welded field joints are used, they shall be single welded butt
> joints or lap welded slip joints, as shown on the drawings. Special
> closure lap joints shall be used as described in AWWA Standard C206.

b.  **Bell and Spigot Joints**

> The dimensions of bells and spigots shall be in accordance with the
> manufacturer\'s standard design dimensions and tolerances.
>
> The pipe shall be laid with the bell oriented upstream. The spigot end
> shall be seated in the bell to a depth as recommended by the
> manufacturer. The spigot, when seated, shall compress the gasket
> radially in its annular recess to provide a positive seal. Joints with
> fish-mouthed gaskets will be taken apart and reseated with a new
> gasket.
>
> Rubber gaskets shall meet the requirements of AWWA Standard C200.

c.  **Mechanical Couplings**

> The ends of pipe to be connected with mechanical couplings shall be
> machined to allow coupling the pipe sections without damaging or
> displacing the gaskets and to ensure uniform end separation of the
> pipes. Machined ends of the pipe that receive the coupling sleeves
> shall be free from dents, gouges, rust, or scale. The pipe and
> couplings shall be assembled with continuous rubber ring gaskets
> conforming to the dimensions and tolerances recommended by the pipe
> manufacturer. Coupling followers shall be drawn up evenly to ensure
> uniform pressure on the gaskets.
>
> Grooved and shouldered joints shall be furnished and installed in
> accordance with AWWA Standard C606.

d.  **Flanged Joints**

> All steel ring flanges shall be fabricated in accordance with AWWA
> Standard C207. Gaskets shall be either a neoprene cloth insert 1/16 or
> 1/8 inch thick or red rubber 1/16 inch thick. The gasket shall be full
> face where used between flat face flange surfaces. All flanged joints
> shall be made up tightly and shall not leak.

e.  **Fitting and Coupling Coatings**

> Compression couplings, mechanical couplings, and flanged fittings
> shall be shop coated with the AWWA Standard C203 coal tar enamel
> coating, as recommended by the coating manufacturer, or a
> factory-applied vinyl coating at least 12 mils thick and as specified
> in this specification. All bolts furnished for flanges, couplings, and
> other types of bolted connections shall be stainless steel or low
> alloy steel and shall be field coated with a coal tar enamel or vinyl
> coating after installation.

## HANDLING

> Coated pipe shall be handled in a manner to prevent abrasion of the
> coating during transportation, placement, and backfilling. Pipe shall
> not be dropped from cars or trucks or allowed to roll down skids
> without restraining ropes. Each section of pipe shall be delivered in
> the field as near as practicable to the place where it is to be
> installed. When stockpiled , it shall be neatly piled and blocked with
> strips between tiers. If the pipe must be moved longitudinally, care
> shall be taken to ensure that the pipe coating are not damaged. Pipe
> shall not be rolled or dragged on the ground. If the pipe is
> supported, as for welding, supports shall be of sufficient width and
> number and be padded, if necessary, to prevent damage to the coating.

## BURIED PIPELINES

> Pipe shall be installed at sufficient depth below the ground surface
> to provide protection from hazards imposed by traffic crossing,
> farming operations, freezing temperatures, or soil cracking. The
> minimum depth of the cover shall be 24 inches, but in soils subject to
> deep cracking, the cover shall be a minimum of 36 inches.
>
> If necessary to install the pipe at a lesser depth, adequate
> protection shall be provided by placing extra fill over the pipeline,
> constructing a fence or other surface barriers, or using extra heavy
> gage pipe.
>
> If trenches are excavated in soils containing rock or other hard
> material that might damage the pipe or coating material, the trenches
> shall be excavated slightly deeper than required and then filled to
> grade with sand or fine earth.
>
> Buried steel pipelines shall be protected with sacrificial galvanic
> anodes if they are specified or otherwise show on the drawings to
> supplement the protection provided by the pipe coating. Anodes shall
> be placed as shown on the drawings. If horizontally placed, anodes
> shall be at or below the bottom elevation of the pipeline. Vertically
> placed anodes shall have a minimum distance to 3 feet between the
> ground surface and the top of the anode. Anodes shall not be placed in
> fill areas, and magnesium anodes must be placed a minimum distance of
> 10 feet from the pipeline.
>
> Anodes shall be bedded in moist fine clay, clay loam, silt, or silt
> loam. In sandy and gravelly areas, fine material must be imported for
> bedding and for covering the anodes to a depth of 6 inches. The
> packaged anodes and the fine textured soil used for bedding and
> backfill shall be thoroughly wetted.
>
> The lead wire from the anode, or the header wire for multiple anode
> installations, shall be attached to the pipeline by cadwelding,
> thermowelding, or other similar processes. Testing station facilities
> shall be located and installed as specified for the job or as shown on
> the drawings, or both, Wires at testing stations shall be attached to
> the pipe by one of the processes specified for anode lead wires.

2.  **PIPELINES INSTALLED ABOVE GROUND**

> Concrete, timber, or other pipe supports, and anchors and thrust
> blocks shall be constructed at the locations to the dimensions shown
> on the drawings and/or as staked in the field. Saddles shall be shaped
> to firmly support the pipe throughout the full arc of contact. At
> least two layers of felt strips shall be placed between the pipe and
> its support unless otherwise detailed on the drawings. The felt shall
> cover the entire area of contact between the pipe and the saddle. A
> graphite lubricant shall be placed between the felt strips before the
> pipe is placed in the saddle.

3.  **PIPELINES INSTALLED ON THE GROUND**

> Pipe shall be laid to the lines and grades as shown on the drawings
> and/or as staked in the field. Pipe shall be protected from the
> hazards imposed by traffic crossings, farm operations, or other
> hazards. The ground shall be shaped so as to provide support needed.
> If there are rocks or objects that might damage the pipe coating, sand
> or soil shall be used as a base for the pipe. Concrete, timber, or
> other anchors and thrust blocks shall be constructed at the locations
> to the dimensions shown on the drawings and/or as staked in the field.

4.  **FIELD LINING, COATING, WRAPPING, AND REPAIR**

> Lining and coating or wrapping of field joints or connections and
> repair of damage to the wrap or coating on pipe, couplings, fittings,
> and appurtenances shall be made in accordance AWWA Standard C203, AWWA
> Standard C209 with Type I or II tape, or AWWA Standard C214, unless
> otherwise as may be shown on the drawings.

a.  **Surface preparation**

> Bare steel surfaces shall be prepared for coating by removing all
> grease and oil or other soluble contaminants with solvent commercial
> cleaners (wiping, dipping, or steam) or vapor degreasing. After
> degreasing, surfaces shall be cleaned with hand tools to remove all
> loose scale rust and other loose detrimental foreign matter.
>
> On previously coated surfaces, all dirt, paper, and other foreign
> matter and loose coating shall be removed. Kraft paper, whitewash, or
> other surface protective layers shall be removed at least 12 inches on
> either side of the bare steel to be coated.
>
> Welds shall be cleaned of all welding slag, splatter, and scale. Sharp
> edges or burrs that could puncture or cut the coating shall be removed
> by grinding or filing. All welds shall be allowed to cool before
> applying primer or coatings.

b.  **Primer application**

> After surface preparation is complete, primer shall be thoroughly
> mixed and applied in strict adherence to manufacturer\'s instructions.
> The primer shall be permitted to dry to the consistency recommended by
> the manufacturer before applying the coating. No foreign matter shall
> come in contact with the primed surface before application of the
> coating. Application of primer to surfaces shall be limited to that
> amount of area that can be wrapped during the same workshift. Primed
> areas not wrapped during the same workshift shall be reprimed. Cold
> weather applications of primer shall be done in accordance with AWWA
> Standard C203.

c.  **Coating application**

> The specified coating shall be applied in accordance with the
> manufacturer\'s recommendations unless otherwise specified.
>
> After assembly, all pipe joints shall be field wrapped in accordance
> with AWWA C209 or AWWA C214, as appropriate. Surface preparation and
> primer application to the ends of the pipe to be wrapped shall be as
> previously described in this specification. A tape or filler tape
> shall be cigarette wrapped over the annular ring of the joint. The
> pipe coating shall be primed 2 inches back from the coating cutback
> and two layers of tape shall be wrapped overlapping 2 inches of pipe
> coating on one side of the joint, extending across the joint and
> overlapping 2 inches of coating on the other side of the joint. Coal
> tar enamel coating cutback edges shall be tapered back until 1 inch of
> coal tar is exposed on the taper before priming and wrapping. Wraps
> shall be terminated on the underside of the pipe. Tape widths shall be
> 6 inches for pipe greater than 8 inches in diameter and 4 inches for
> pipe 2 to 8 inches in diameter.
>
> Welded field joints of lined pipe shall be lined in accordance with
> AWWA Standard C203, Section 4.3.

d.  **Repair and patching factory coatings**

> All loose or disbonded material shall be removed from the area of the
> \"holiday.\" All points, burrs, or rough edges shall be smoothed to a
> feathered edge. The surface shall be cleaned and prepared as specified
> for joints, couplings, and fittings. The area to be cleaned and
> prepared shall be at least twice the size of the \"holiday.\" The
> repair coating shall be worked onto the surface of the steel to leave
> no voids or wrinkles on the surface.
>
> Coal tar enamel coatings shall be repaired in accordance with AWWA
> Standard C203, Section 2.15. Tape coatings shall be repaired in
> accordance with AWWA Standard C214, Section 3.4, Coating Repair. The
> repair shall be made by wrapping tape around the circumference of the
> pipe.
>
> All damaged vinyl coat areas shall be cleaned and recoated in
> accordance with the manufacturer\'s recommendation.

5.  **TESTING**

> Underground steel pipelines shall be tested before placing the
> backfill over the field joints. Aboveground steel pipelines may be
> tested at any time after they are ready for operation.
>
> The pipeline shall be filled with water, taking care to bleed air and
> prevent water hammer. When the line is full, all valves shall be
> closed, and the line shall be brought up to full design working
> pressure. All joints shall then be carefully inspected for leakage and
> any visible leaks shall be repaired.
>
> It shall be demonstrated by testing that all valves, vents, surge
> chambers, and other appurtenances function properly when the pipeline
> is operated at design capacity. Objectionable surge, water hammer,
> unsteady delivery of water, damage to the pipeline, and detrimental
> discharge from control valves are evidence of malfunction.

6.  **MEASUREMENT**

> The quantity of each size and type of pipe shall be determined to the
> nearest foot by measurement of the laid length of pipe along the crown
> centerline of the pipe.
>
> Project Name:
>
> Date:

7.  **ITEMS OF WORK AND CONSTRUCTION DETAILS**

> Items of work to be prepared in conformance with this specification
> and the construction details are: