NATURAL RESOURCES CONSERVATION SERVICE

**Idaho**

**CONSTRUCTION SPECIFICATIONS**

**FOR**

> **IRRIGATION WATER CONVEYANCE**
>
> **STEEL PIPE**

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

(Owner/Operator)

\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

(Project/Title)

GENERAL

This specification covers the installation and materials steel pipe.
Pipelines shall be installed in accordance with a design and plan
approved by the responsible technician. Details of construction shown in
the design and plan but not included here shall be considered as a part
of this specification. Construction activities shall be in accordance
with applicable OSHA regulations.

INSTALLATION

Pipe shall be the diameter, length, thickness and be coated as specified
on the drawings.

The pipe shall not be handled in a manner to cause damage to the pipe
and its coating. The pipe shall not be rolled or dragged on the ground.
The pipe shall be lowered into the trench or onto the above ground
supports by the use of canvas slings or padded cables. Individual joints
of pipe shall be inspected and any damaged pipe, including coating(s)
shall be removed and repaired or replaced.

Vertical alignment of pipe shall be uniform and such as to maintain the
cover requirements unless otherwise noted on the drawings. If irregular
grades are required, thrust blocks, air releases, drains and other
appurtenances as needed shall be installed.

All joints and connections shall be constructed to withstand the design
working pressure for the pipeline without leakage and shall leave the
inside of the pipeline free of any obstruction which could reduce the
pipe capacity below design requirements.

Surfaces of the pipe joints shall be cleaned before making joint
connections.

All fittings, such as couplers, reducers, bends, tees, risers and
endives and all valves and other appurtenances shall be made of
material(s) that is recommended for use with the pipe and shall have
coatings equal too or exceeding that specified for the pipe and shall be
installed in accordance with the recommendations of the manufacturer.

The pipeline appurtenances shall be of the type, size, material and
pressure class as shown on the drawings. Unless otherwise shown on the
drawings all Butterfly valves shall be equipped with geared operators.

# Air and vacuum relief valves and/or combination air and vacuum relief valves shall be installed at locations shown on the drawings.

# Pressure relief valves shall be stamped with the pressure at which the valve starts to open. Adjustable valves shall be sealed or otherwise altered to insure that the setting marked on the valve is not changed.

# Check valves shall be rated as quick-closing, non-slamming.

# Drain valves shall be installed at low points in the pipeline unless provisions are made for pumping out the pipeline.

Risers shall be of the diameter and spaced as specified on the drawings.
Steel risers shall have a coating with no less than a Class B rating.

The coatings on all valves and appurtenances shall be rated no less than
the Class of the pipeline coating specified. All valves shall be
installed in accordance with special Manufacturer recommendations.

SURFACE INSTALLATIONS

Pipe shall be supported a minimum of one foot above the ground by
supports/saddles as shown on the drawings. Two layers of felt strips
shall be placed between the pipe and the support. A graphite lubricant
shall be placed between the pipe and the felt strip. Treated wood shall
be used for timber supports.

Above ground welded joint pipelines shall have expansion couplers
installed at a spacing not to exceed 400 feet. The maximum distance
between a coupler and a fixed or anchored location shall be 200 feet.
Couplers shall provide for a minimum of 4 inches of travel distance.

BURIED INSTALLATIONS

[Trench Construction]{.underline}. Trench width at any point below the
top of the pipe should be only wide enough to permit the pipe to be
easily placed and joined and to allow the initial backfill material to
be uniformly placed under the haunches and sides of the pipe. The
minimum trench width shall be not less than two pipe diameters, unless
the trench is precision excavated with a semicircular bottom that
closely fits the pipe. Trench banks that are more than 5 feet high shall
be shored or sloped. Refer to Figure 1 for typical trench details.

Power transmission lines shall not be placed in the same trench as the
pipe.

Where rock, hardpan, cobbles or other hard material which might prevent
the pipe from being uniformly supported is encountered in the bottom of
the trench, the trench shall be undercut a minimum of four inches below
final grade. The over cut area of the trench will then be filled with
sand or fine-grained soil.

[Bedding]{.underline}. The pipe shall be firmly and uniformly bedded
throughout its entire length. Bedding material shall be placed and
spread in uniform layers and in such a manner as to fill the trench so
there are no unfilled spaces below the pipe. For pipe with bell joints,
holes shall be dug in the bedding at the bells to permit the body of the
pipe to be in contact with the bedding along its entire length. Blocking
or mounding shall not be used to bring the pipe up to final grade.

[Initial Backfill]{.underline}. The initial backfill material shall be
soil or sand that is free from rocks, gravels, frozen materials larger
than 1 inch or earth clods greater than 2 inch in diameter. This may be
the on site trench excavated materials as long as any unsuitable
materials are removed. The initial backfill materials shall be placed in
a manner as not to displace, deform or damage the pipe.

Hand, mechanical or water packing are optional methods for placing and
compacting pipe backfill.

When backfilling is done by hand or mechanical means the initial fill
shall be compacted firmly around and above the pipe to achieve a soil
density equal or greater than the density of the undisturbed side walls
of the trench. The thickness of individual lifts prior to compaction
shall not exceed 6 inches.

When water packing is used, the pipe shall be filled with water. The
initial backfill, before wetting, shall be of sufficient depth to ensure
complete coverage of the pipe with backfill after consolidation has
taken place. Water packing shall be accomplished by adding water to
diked reaches of the trench in such quantity as to thoroughly saturate
the initial backfill. After the backfill is saturated, the fill shall be
consolidated by rodding or with a vibrator. The wetted fill shall be
allowed to dry before until firm before completing the final backfill.

[Final Backfill]{.underline}. The final backfill material shall be free
of rocks, frozen clods or other debris larger than 1 inch in diameter
within 6 inches of the pipe and 6 inches in particle size for the
remaining portion of the final backfill unless otherwise specified on
the drawings. The material shall be placed and spread in approximately
uniform layers so there are no unfilled spaces in the backfill. Rolling
equipment shall not be used until a minimum of 18 inches of compacted
backfill material has been placed over the top of the pipe. Final
backfill may be mounded over the top of the trench above ground level,
but in no case shall the final backfill be lower than the natural ground
along the top of the trench.

All special backfilling requirements of the pipe manufacturer shall be
followed.

[Expansion Couplers]{.underline}. Below ground welded joint pipelines
shall have expansion couplers installed at a spacing not to exceed 600
feet. The maximum distance between a coupler and a fixed or anchored
location, such as a tee, bend or riser shall be 300 feet. Expansion
couplers are not required within reaches of pipe with risers. Expansion
couplers shall provide for a minimum of 4 inches of travel distance.

[Joints and Connections]{.underline}. High resistance joints between
pipe lengths shall be electrically bridged with a welded, brazed or
soldered copper wire not smaller than 4/0 gauge in size. When coated
pipe is welded, care shall be taken to avoid burning the coating. After
the joints are welded they shall be covered with a coating equal in
quality to that specified for the pipe.

Diaelectric couplers shall be placed between the following locations:

> \- Pump(s) and pipeline
>
> \- Pipe reaches with different coatings
>
> \- Pipe of different ages

Flanges with gaskets and bolt insulation, short sections of PVC pipe or
other positive means of insulation are acceptable.

[Cover]{.underline}. The minimum depth for backfill over the top of the
pipe is:

> [18 inches]{.underline} for pipe 1/2 inch through 2-1/2 inch in
> diameter
>
> [24 inches]{.underline} for pipes 3 inch diameter and larger

At low places on the ground surface or at locations where it is shallow
to rock, extra fill may be placed over the pipeline to provide the
minimum depth of cover. In such cases, the top width of the fill shall
be no less than 10 feet and the side slopes no steeper than 6 horizontal
to 1 vertical.

COATINGS

All buried pipe shall have an outside coating of at least Class B as
specified on the drawings or listed in the ADDITIONAL SPECIFICATIONS.
When Class A coatings are required per the drawings refer to the
ADDITIONAL SPECIFICATIONS for the coating requirements.

The following types of coatings may be used when Class B coatings are
specified:

> Coal-Tar-Enamel coatings meeting the requirements of AWWA C203,
> "Coal-Tar Protective Coatings and Linings for Steel Water Pipelines --
> Enamel and Tape -- Hot Applied".
>
> Epoxy coatings meeting the requirements of AWWA C210, "Liquid-Epoxy
> Coating Systems for the Interior and Exterior of Steel Water
> Pipelines" or AWWA C213, "Fusion-Bonded Epoxy Coating for Interior and
> Exterior of Steel water Pipelines". The coating shall have a minimum
> thickness of 16 mils.
>
> Prefabricated tape meeting the requirements of AWWA Standard C209
> "Cold Applied Tape Coatings for the Exterior of Special Section,
> Connections, and Fittings for Steel Water Lines". Ape coatings shall
> have a minimum thickness of 20 mils.
>
> Tape coatings meeting the requirements of AWWA C214, "Tape Coating
> Systems for the Exterior of Steel Water Pipelines".

Fittings made of steel or other materials susceptible to corrosion shall
(1) be wrapped with plastic tape meeting the requirements of AWWA C 209
for Type I or II tape, or (2) coated with coal-tar epoxy paint
(Kippers-Bitumastic No. 300-M is an approved off the shelf product), or
(3) coated with epoxy paint in accordance with the Steel Structures
Council (SSPC) Paint Specification \# 16.

Steel pipe installed above ground shall be painted with one coat of
urethane primer applied at a rate of 2 to 3 mils thick and two or more
coats of gloss or semi-gloss Alkyd Enamel to provide a minimum thickness
of 6 mils.

When an interior pipe coating is specified, the coating shall meet the
following requirements:

> Coal-Tar-Enamel meeting the requirements of AWWA C203, "Coal-Tar
> Protective Coatings and Linings for Steel Water Pipelines -- Enamel
> and Tape -- Hot Applied".
>
> Cement mortar lining applied in accordance with ASTM C205,
> "Cement-Mortar Protective Lining and Coating for Steel Water Pipe-4
> in. (100mm) and Larger-Shop Applied".
>
> Epoxy coatings meeting the requirements of AWWA C210, "Liquid-Epoxy
> Coating Systems for the Interior and Exterior of Steel Water
> Pipelines" or AWWA C213, "Fusion-Bonded Epoxy Coating for Interior and
> Exterior of Steel water Pipelines".

CATHODIC PROTECTION

When specified buried pipelines shall be protected with sacrificial
galvanic anodes as needed to supplement the protection of the specific
pipe coating. The anodes shall be of the kind and number as shown on the
drawings.

Anodes shall be commercially packaged of magnesium or zinc. Zinc anodes
shall meet the requirements of ASTM B418. Anodes shall have a full
length core with a single strand of insulated copper wire solidly
attached to it. The wire shall be No. 12 or larger. If a header wire is
used, the wire gauge must be sufficient to carry the design current with
n more than a 20 millivolt I-R drop.

The package mix for the anodes shall be proportioned by weight as
follows:

> Zinc -- 20 to 30% bentonite
>
> 70 to 80% gypsum

Magnesium -- 20 to 25% bentonite

> 70 to 80 % gypsum
>
> 5 % sodium

Anodes may be placed either horizontally or vertically. When placed
horizontally, they shall be at or below the bottom elevation of the
pipeline. Vertically placed anodes shall have a minimum distance of
three feet between the ground and the top of the anode.

Anodes shall not be placed in fill areas and magnesium anodes shall be
placed no closer than ten feet from the pipeline.

Anodes shall be bedded and covered with a minimum 6-inch thickness of
moist fine clay, clay loam, silt or silt loam soils materials. The
packaged anodes and the soil bedding and covering shall be thoroughly
wetted.

The lead wire from the anode or header wire shall be attached to the
pipeline by CAD welding, thermowelding, or other process of equal
result. The weld area shall be covered with a coating equal in quality
to the pipe coating.

Testing stations shall be located and installed as specified on the
drawings. Wires attached to the pipe shall as specified fir the anode or
header wires.

VALVES AND APPURTENANCES

The pipeline valves and appurtenances shall be of the size, type,
material and pressure rating as shown on the drawings. Unless otherwise
shown on the drawings all Butterfly valves shall be equipped with geared
operators.

Air and vacuum relief valves and/or combination air and vacuum relief
valves shall be installed at locations shown on the drawings.

Pressure relief valves shall be stamped with the pressure at which the
valve starts to open. Adjustable valves shall be sealed or otherwise
altered to insure that the setting marked on the valve is not changed.

# Check valves shall be rated as quick-closing, non-slamming.

Thrust blocks shall be formed against a solid trench wall. They shall be
of the minimum size and materials as specified on the drawings.

MATERIALS

Pipe shall equal or exceed the requirements of the applicable
specification for the kind of pipe and the type, weight, grade and
finish specified:

> American Water Works Association (AWWA) C-200 "Steel Water Pipe - 6
> in. (150mm) and Larger"
>
> ASTM A 53 "Pipe, Steel, Black and Hot-Dipped, Zinc Coated Welded and
> Seamless"
>
> ASTM A 134 "Pipe, Steel, Electric-Fusion (ARC)-Welded (Sizes NPS 16
> and Over)
>
> ASTM A 135 "Electric-Resistance-Welded Steel Pipe"
>
> ASTM A 139 "Electric-Fusion (ARC)-Welded Steel Pipe (NPS 4 and Over)"

Fittings shall conform to the requirements for the types and kinds
specified.

> ASTM A 858 "Heat-Treated Carbon Steel Fittings for Low-Temperature and
> Corrosive Service"
>
> ASTM A 865 "Threaded Couplings, Steel, Black or Zinc-Coated
> (Galvanized) Welded or Seamless, for Use in Steel Pipe Joints"

The minimum pipe wall thickness shall be as follows:

-   \< 3 inch nominal diameter Schedule 40

-   3 through 4 inch nominal diameter 0.0747 inch less 12.5%

-   4 through 18 inch nominal diameter 0.1046 inch (12 Gauge) less 12.5%

-   20 through 24 inch nominal diameter 0.1345 inch (10 Gauge) less
    12.5%

-   26 through 36 inch nominal diameter 3/16 inch less 12.5%

-   38 through 48 inch nominal diameter ¼ inch less 12.5%

TESTING

When water is available at the time the pipe is being installed the
system shall be given an operational test. This test shall consist of
filling the pipe with water, taking care to bleed of any air in the
pipe. All of the system components shall operate without difficulty.
Leakage or defects caused by poor materials or workmanship shall be
replaced or repaired. When water is not available to complete a test,
the installer shall provide a guarantee stating they will return and fix
leaks that are found when the pipe is initially filled with water.

GUARANTEE

The installing Contractor shall certify that the installation conforms
to the requirements of this specification. The certification will list
manufacturer of pipe and applicable pipe markings.

ADDITIONAL SPECIFICATIONS

FIGURE 1

> TRENCH WIDTH AND BACKFILL REQUIREMENTS
>
> NATURAL GROUND
>
> FINAL BACKFILL
>
> 6" FINAL BACKFILL
>
> (Maximum particle size 1 inch)
>
> INITIAL BACKFILL

OD (Compacted select

0.7 OD 4" bedding materials)

> MINIMUM DIMENSIONS
>
> (If Necessary) 0.5 OD
>
> TYPICAL TRENCH DETAIL
>
> 5 FT DEPTH, MAXIMUM
>
> NATURAL GROUND
>
> 1
>
> FINAL BACKFILL \*\*
>
> FINAL BACKFILL
>
> (Maximum particle
>
> size 1 inch)

OD

0.7 OD INITIAL BACKFILL

> (Compacted select
>
> bedding materials)
>
> 4" (If Necessary) MINIMUM DIMENSIONS
>
> 0.5 OD
>
> ALTERNATIVE TRENCH DETAIL

DEPTH GREATER THAN 5 FEET

> \*\* Slope typically varies from ¾ to 1/1/2:1 or greater based upon
>
> material classification and other factors such as wetness, vibration,
>
> surcharge, etc. Refer to OSHA Subpart P for details.