Division 13
Special Construction
SECTION 13010
BOLTED STEEL WATER STORAGE TANK
PART 1 - GENERAL
1.1
SECTION INCLUDES
A. This section includes the furnishing of all labor, tools, equipment, and materials necessary to design,
fabricate, coat, package for shipment, deliver, and erect a factory-coated, bolted, steel, insulated, potable
water storage tank, including tank design, foundation design, and tank appurtenances as shown in the
Drawings and described herein.
B. The Contractor shall field erect the water tank on a concrete ring wall foundation as shown on the
Drawings and any tank manufacturer’s foundation design drawings. The foundation shall conform to
seismic requirements, tank manufacturer’s foundation design, manufacturer’s recommendations, and the
Drawings.
C. The tank design, materials, fabrication, and erection shall conform to the current Standard D103 of the
American Water Works Association (AWWA D103) and to these Specifications and the Drawings. These
Specifications and the Drawings show foundation type, nominal tank dimensions, capacity, size, and
location of the required piping and appurtenances.
D. All materials furnished by the tank manufacturer, which are in contact with stored water, shall be certified
to meet ANSI/NSF Standard No. 61. Certification of a coating type alone will not be sufficient to meet this
requirement. Certification of the coating manufacturer is required.
1.2
RELATED SECTIONS
A. Section 01300 - Submittals.
B. Section 02300 - Earthwork.
1.3
REFERENCES
A. The latest revision of the following standards of the American Society for Testing and Materials (ASTM),
American Water Works Association (AWWA), and International Building Code (IBC) are hereby made
part of this Specification. The publications may be referred to in the text by basic designation only.
1.
ASTM
A36
Standard Specification for Carbon Structural Steel.
2.
ASTM
A283S
Standard Specification for Low and Intermediate Tensile Strength Carbon
Steel Plates.
3.
ASTM
A307
Standard Specification for Carbon Steel Bolts and Studs, 60,000 psi
Tensile Strength.
4.
ASTM
A325
Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105
ksi Minimum Tensile Strength.
5.
ASTM
A570
Standard Specification for Steel, Sheet and Strip, Carbon, Hot Rolled,
Structural Quality.
6.
AWWA
C652
Standard for Disinfection of Water Storage Facilities.
Lowell Point Community Water System
13010 - 1
Bolted Steel Water Storage Tanks
1.4
7.
AWWA
8.
OSHA
9.
NSF
D103
Standard for Factory-Coated Bolted Steel Tanks for Water Storage.
Occupational Safety and Health Administration; Chapter 27, Fixed
Ladders.
61
National Sanitation Foundation Standard 61 – Drinking Water System
Components.
SUBMITTALS
A. Bid Submittal: All bidders are required to submit one set of material samples and three (3) sets of
manufacturer’s literature as part of their bid. If the submitted system fails to meet the specifications, or if
the bidder does not submit the required materials with his bid, he will be considered non-responsive and his
bid rejected. Submittals shall conform to Section 01300 - Submittals.
B. Structural Calculations: The tank manufacturer shall submit a complete set of step-by-step tank design
calculations and a tank foundation design for approval after award of the contract, but prior to tank
fabrication. The tank shall not be fabricated until the calculations are approved. The calculations shall
conform to the latest revision of AWWA D103 and shall show all calculations used in designing the tank
foundation and the tank and reference all formulas and data sources. Calculations shall be legible and
annotated. Spreadsheets and other computer printouts without written explanation and equations are not
acceptable. Stiffness calculations shall be based on an empty tank.
C. Shop Drawings:
1.
Submit Shop Drawings showing all principal dimensions of the tank, details and locations of all
accessories and appurtenances, thickness of sheets and plates and details of joints and welds.
2.
Shop Drawings shall include a description of the protective coating system and a general plan of the
structure showing a layout of the tank panels.
3.
Shop Drawings shall indicate the number of bolts/nuts required to build the tank, number of bolts
/nuts per a unit weight and/or weight of bolts/nuts supplied.
4.
Shop Drawings shall include the description and plans of the insulation retention system. Provide
manufacturer’s literature for the insulation, showing that it meets or exceeds the Specifications.
5.
One copy of the shop Drawings shall be reproducible.
6.
Shop Drawings shall be sealed by a Civil Engineer registered in the State of Alaska.
7.
The tank shall not be fabricated until the Shop Drawings are approved.
D. Coatings:
1.
The tank manufacturer shall provide paint chips for color selection by the Owner.
2.
Tank manufacturer’s proposed painting schedule, for Owner’s Representative approval.
E. Packaging System:
F.
1.
The tank manufacturer shall submit sketches and a brief narrative of the proposed packaging system.
2.
Photographs are acceptable in lieu of sketches.
Packing Lists: The tank manufacturer shall submit shipping packing lists, detailing all materials shipped
and referencing the crate number each is in. The packing lists will be provided to the Owner prior to the
delivery date of the tank.
Lowell Point Community Water System
13010 - 2
Bolted Steel Water Storage Tanks
G. Erection Manual: The tank manufacturer shall submit field erection manuals illustrating the erection and
installation procedures for the tank and each appurtenance furnished. The manuals and drawings shall be
provided to the Owner prior to the delivery date of the tank.
H. Mill Test Reports: The tank manufacturer shall provide copies of certified mill-test reports.
1.5
I.
Coating Thickness Test Data: The tank manufacturer shall provide copies of certified test data on the
coating thickness.
J.
The Contractor shall provide certification along with adequate supporting information for Owner’s
Representative approval indicating the requirements of Subpart 1.7 – Qualifications of Contractor have
been met. This certification shall be submitted at least 14 days before tank erection begins.
DELIVERY, STORAGE AND HANDLING
A. Packing, Shipping and Handling:
1.
Protect sheets from damage prior to packing for shipment. Place heavy paper or plastic foam sheets
between each panel to eliminate sheet-to-sheet abrasion.
2.
Wrap individual stacks of panels in heavy plastic. Steel band panels to special wood pallets built to
the roll radius of the tank panels.
3.
Packaging must meet the shipping requirements of all anticipated carriers and shall prevent abrasion,
scratching or damage of the materials under extremely adverse weather and handling conditions.
4.
Floor and roof panels shall be packaged separately, not intermittently stacked together.
5.
Packaging must be suitable for lifting by forklift and cable sling.
6.
Individual package weight shall not exceed 5,000 lbs each.
B. Storage: The packaging shall provide adequate protection for the fabricated materials and appurtenances
for outside storage at the site throughout the construction project.
1.6
MANUFACTURER
A. Tank manufacturer shall have a minimum of five years experience including the manufacture of at least
five similar tanks in the previous three years.
1.7
QUALIFICATIONS OF CONTRACTOR
A. The Contractor shall erect the tank with erectors that have a minimum of five years of similar erection
experience. The tank erectors must be employed by the Contractor. Subcontractor erectors are prohibited
unless otherwise approved in writing by the Owner’s Representative.
B. The Contractor shall be fully responsible for the entire installation including tank erection and the ultimate
water tightness of the complete installation.
1.8
QUALITY ASSURANCE
A. The tank manufacturer shall provide the Owner’s Representative written certification that the tank has been
designed and fabricated in accordance with the requirements of AWWA D103, and is suitable for potable
water storage.
B. The tank manufacturer shall provide certification of the protective coating material and coating
manufacturer, that the material is non-toxic and will not impart taste or odor to the water.
Lowell Point Community Water System
13010 - 3
Bolted Steel Water Storage Tanks
C. Upon completion of the tank, the Contractor shall provide the Owner’s Representative written certification
that the tank has been erected and tested in accordance with the manufacturer’s recommendations and with
the requirements of AWWA D103, and is suitable for potable water storage.
1.9
DESIGN REQUIREMENTS
A. General:
1.
Inside nominal diameter and sidewall heights are shown on the Drawings. The tank manufacturer
shall recommend the actual diameter, sidewall height, and freeboard required based on the tank
supplier’s seismic calculations.
2.
The tank shall be designed to withstand seismic forces from ground motion accelerations anticipated
for local siesmic and site conditions. The design analysis shall use the seismic design approach as
described in the latest revision of AWWA D103.
3.
Tanks shall be designed for liquids with a specific gravity of 1.0.
4.
The design snow load shall be 50 psf.
5.
The design wind velocity shall be 130 MPH.
6.
Platform and ladder load shall be as described in the latest revision of AWWA D103 and OSHA
Chapter 27.
B. Water Storage Tank:
1.10
2.
Water storage tank shall be capable of storing the required volume of potable water.
3.
Water storage tank shall be designed for all anticipated loadings including dead and live gravity
loads, seismic loads and the snow loads and wind velocity shown on the Plans and described in these
Specifications.
TANK MANUFACTURER’S WARRANTY
A. The tank manufacturer shall include a warranty for the tank materials and coating. As a minimum, this
warranty shall provide assurance against defects in material, coatings, and workmanship for a period of five
years.
PART 2 - PRODUCTS
2.1
MATERIALS
A. Factory Coated Bolted Steel Water Storage Tank:
1.
2.
Steel Sheets, Plates and Shapes:
a.
Steel sheets shall have a minimum thickness of 12 gauge and shall conform to ASTM A570, Grade
36, hot rolled structural quality, having a minimum yield strength of 36,000 psi.
b.
Steel plates shall conform to ASTM A283, Grade C, having a minimum yield strength of 30,000 psi.
c.
Structural Shapes: Hot-rolled structural shapes shall conform to AISC S326. The material shall
conform to ASTM A36.
Bolts:
a.
Bolts and nuts for joining tank panels shall conform to ASTM A307, A325 or API 12B.
b.
All bolt heads exposed to the interior of the tank shall be polycapped.
c.
Encapsulated nuts shall be furnished for all nuts exposed to the tank interior.
Lowell Point Community Water System
13010 - 4
Bolted Steel Water Storage Tanks
d.
3.
2.2
The tank manufacturer shall furnish bolts, nuts and washers 10% in excess of the quantities needed.
Gaskets: Gaskets and sealants shall conform to the latest revision of AWWA D103.
TANK APPURTENANCES
A. Factory Coated Bolted Steel Water Storage Tank:
1.
2.
3.
4.
5.
Tank Floor:
a.
The tank floor is to be an epoxy-coated bolted steel floor.
b.
Square Floor Sump:
i.
Location and Dimensions of the sump shall be as shown on the Drawings.
ii.
Fabrication requirements of the sump shall be of the same standard as the tank.
iii.
Sump shall be installable from the top side of the tank floor, unless otherwise noted on the
Drawings.
Roof:
a.
Roof Decks (Two Total): The tank shall include two radially sectioned roofs fabricated from epoxycoated, bolted panels as produced by the tank manufacturer. The roof shall be clear-span and selfsupporting or center-supported. Both live and dead loads shall be carried by the tank walls and any
center supports.
b.
The second roof deck must be compatible with the first deck bolt patterns for ease of installation.
Shell Manways:
a.
Two manways as shown on the Drawings. Both manways shall consist of a bolt on manway with
hinge and cover.
b.
Hinge shall be capable of vertical and horizontal adjustment.
c.
Manway neck shall extend 11 inches beyond tank shell.
d.
All manways shall be of the standard design by the manufacturer and shall meet all requirements of
the latest revision of AWWA D103.
Pipes and Fittings:
a.
The tank manufacturer shall furnish all pipes, fittings, supports, and appurtenances as shown on the
Drawings.
b.
The Contractor shall furnish all pipes, fittings, supports and appurtenances as shown on the Drawings
and not provided by the tank manufacturer.
c.
The overflow shall be equipped with weir cone, downspout and 90 degree bend discharge and bug
screen as shown on the Drawings.
d.
Weir cone height shall be specified by the tank manufacturer.
e.
Overflow pipe shall be adequately supported on the outside of the tank with steel brackets, coated to
same specification as tank exterior, as provided by the tank manufacturer.
f.
Where pipe connections are shown to pass through tank panels, they shall be factory placed. The
tank shell reinforcing shall comply with AWWA D103. Mastic sealant conforming to the
requirements of AWWA D103 shall be provided.
g.
All required flange bolt holes and nozzle openings shall be drilled and cut respectively in the tank
wall in the locations shown on the approved Shop Drawings at the time of fabrication, prior to
coating.
Roof Vent:
Lowell Point Community Water System
13010 - 5
Bolted Steel Water Storage Tanks
6.
7.
a.
Roof vent shall be bolt-on center deck dome as shown on the Plans.
b.
A properly sized vent assembly shall be furnished in accordance with the latest revision of AWWA
D103 above the maximum water level of sufficient capacity so that at maximum possible rate of
water fill or withdrawal, the resulting interior pressure or vacuum will not exceed 0.5 inches water
column. Maximum fill and draw flow rates are shown on the Plans for normal operating conditions.
c.
Hot dipped galvanize the roof vent assembly.
d.
The overflow pipe shall not be considered as a tank vent.
e.
The vent shall be so designed in construction as to prevent the entrance of birds or other animals by
including an expanded aluminum screen (1/2-inch opening). Provide an insect screen of 23 to 25
mesh polyester monofilament designed to open should the screen become plugged by ice formation.
Square Roof Deck Manway:
a.
The manway shall have an 11 inch neck and an opening 24 inches square.
b.
The manway cover shall have a downward neck overlap of 2 inches, and shall be hinged and
equipped with a locking hasp.
c.
The neck and cover shall be fabricated to be compatible with the upper roof decking and allow
adequate clearances.
Outside Tank Ladder:
a.
The outside tank ladder shall consist of a vertical galvanized steel ladder extending from the tank
bottom to the tank roof as shown on the plans.
b.
The ladder shall be a minimum of 16 inches wide and shall have a 16-inch clearance from the side of
the tank.
c.
The ladder shall be attached to the tank shell with brackets placed at minimum intervals of 8 feet and
shall be enclosed with a suitably sized cage from 8 feet above the tank bottom to 12 inches above the
height of the perimeter handrail. The cage shall be equipped with a hinged entry gate and locking
hasp.
d.
The ladder and cage shall be of standard design as supplied by the tank manufacturer and shall be
designed to OSHA requirements for support and safety of fixed ladders.
e.
The anti-climb gate shall be 10-gauge minimum thickness and shall be provided with a minimum of
2 heavy-duty hinges.
8.
Tank Internal Supports (for center-supported roof design): The center column and column base shall
be rigidly attached to the tank bottom to resist lateral movement in conformance with the
manufacturers instructions.
9.
Tank Internal Piping: The tank internal piping shall be constructed from Schedule 40 steel, coated
on the inside and outside using interior coating as specified herein, and installed as shown in the
Drawings. The tank internal piping supports shall be of the tank manufacturers design. Internal
piping and piping supports shall be provided by the tank manufacturer.
10. Perimeter Handrail:
a.
A perimeter handrail shall be provided as shown on the Drawings.
b.
The handrail shall be of the tank manufacturers design and shall conform to all applicable sections of
the most current publication of the IBC and meet OSHA requirements for support and safety.
c.
All handrail material and fasteners shall be hot-dipped galvanized steel.
11. Level Indicator
a.
A double-throw mechanical level indicator gauge board sized for the tank height using a stainless
steel float and cable or approved equal shall be provided.
Lowell Point Community Water System
13010 - 6
Bolted Steel Water Storage Tanks
b.
The indicator board shall be heavy-duty industrial aluminum. The board will show depth of water in
feet with minimum 4-inch numerals. The board shall be painted white and the level indicator black.
c.
The indicator board shall be attached to the tank such that it is not covered by the insulation system.
12. Identification Plate:
a.
Tank manufacturer’s nameplate shall list the tank serial number, tank diameter and height, and
maximum design capacity.
b.
The identification plate shall be mounted between the inlet and outlet ports, or as recommended by
the tank manufacturer.
13. Tank Insulation System:
2.3
a.
The tank manufacturer shall provide the tank insulation system as shown in the Drawings.
b.
Roof deck board insulation shall be 40 psi extruded polystyrene (Dow Highload 40). Wall board
insulation subbase panels shall be 25 psi expanded polystyrene. Pre-fabricated, pre-curved wall
insulation panels shall be 2-inch, foil-faced (both sides) isocyanurate foam. The thermal conductivity
(K-value) of the isocyanurate foam insulation shall be a maximum of 0.140 BTU-in/ft2-hr-oF, at 75oF
mean temperature.
c.
Exterior sheeting shall be 24-gauge steel sheeting or 1/32-inch 3105H18 alloy aluminum.
d.
The insulation system sheeting and covering system shall be weathertight.
e.
Manway insulation covers shall be form-fitting, removable, and be provided by the tank
manufacturer. R-Value to meet or exceed tank body insulation.
COATINGS
A. The tank coating system shall conform to Section 12.5 – Thermoset Liquid Suspension Coatings (AWWA
D103-2009). The coating system for the tank and accessories shall be as specified in these Specifications
and on the Drawings. Inspection shall be conducted by the tank manufacturer during the coating process
on randomly selected test panels. Any deficiencies identified during the inspection shall be corrected at the
manufacturer’s expense.
B. A thermally cured epoxy paint system shall be supplied. The protective paint system shall meet the
following procedural and materials qualifications.
1.
Preparation of Surfaces for Painting: All steel, including plates, members, and appurtenances, shall
be blast cleaned in accordance with Steel Structure Painting Council - Surface Preparation
Specification No. 10 (SSPC-SP10). The surface anchor pattern shall be not less than 1.0 mil or
greater than 3.0 mils. No shaping, bending, punching, flanging, or grinding may be done on the steel
after blast cleaning and before painting.
2.
Interior Painting: All interior steel surfaces, members, and parts, including all surfaces of internal
piping, shall be painted with a two-part, two-coat, thermally cured epoxy paint system in strict
accordance with NSF-61 standards and manufacturer’s recommendations.
The minimum
recommended dry film thickness shall be 5 to 7 mils. The paint used must be acceptable to the
Environmental Protection Agency (EPA) and certified that no health hazard is expected to occur
when in contact with potable water. The tank manufacturer shall provide finished interior paint
color chips for approval by the Owner’s Representative.
3.
Exterior Painting: All exterior steel surfaces, members, and parts shall receive one (1) coat of
thermally cured epoxy ester primer having maximum dry film thickness of 3 mils, and one (1)
thermally cured acrylic finish coat. The finish dry film thickness shall be a minimum of 4 mils. The
tank manufacturer shall provide paint chips for color selection by the Owner.
Lowell Point Community Water System
13010 - 7
Bolted Steel Water Storage Tanks
4.
Exterior Sheeting: The exterior sheeting for the insulation system shall be double-coated and
double-baked with acrylic enamel or powder. The tank manufacturer shall provide paint chips for
color selection by the Owner.
5.
Application of Paint: The Contractor shall submit to the Owner’s Representative, for his/her
approval, the tank manufacturer’s proposed painting schedule. At minimum, this shall include the
spreading rate in square feet per gallon for each coat, minimum dry film thickness for each coat,
application temperature, curing time and temperature, humidity limits, and paint and paint thinner to
be used for the final coat. The painting schedule shall be in accordance with the paint
manufacturer’s recommendation, and shall be approved, in writing, by the Owner’s Representative
prior to application.
6.
If paint is diluted for application by spray gun, the coating shall be built up to the same film
thickness achieved with undiluted material. Deficiencies in film thickness shall be corrected by the
application of an additional coat(s) of paint.
7.
Inspection and Testing: Tank manufacturer’s inspection shall include a mil thickness test on both
the interior and exterior surfaces of not less than 30% of the tank panels.
C. The tank manufacturer shall provide a procedure for field repair and touch-up of damaged coating, and
shall furnish five (5) gallons of the requisite paint.
PART 3 - EXECUTION
3.1
FOUNDATION
A. The Contractor shall install the tank foundation as shown in the Drawings and the tank manufacturer’s
approved Shop Drawings.
3.2
TANK ERECTION
A. Field erection of the factory coated bolted steel water tank and tank insulation system shall be in strict
accordance with the manufacturer’s instructions. The Contractor shall exercise particular care in handling
and bolting of the tank plates, supports, and members to avoid abrasion or scratching of the coating.
3.3
COATING REPAIR
A. Any damage to the factory-applied coating shall be repaired and restored to the original finish in strict
compliance with the manufacturer’s recommendations.
B. The tank shall be visually inspected by the Contractor and the Owner’s Representative, both internally and
externally, before installing the insulation system. Contractor shall provide inspection assistance to the
Owner’s Representative.
3.4
CLEANUP
A. On completion of the tank erection, the Contractor shall remove or dispose of all rubbish or other unsightly
material caused by the operation and shall leave the premises in as good a condition as that found at the
start of construction.
3.5
TANK TESTING
A. Following the completion of erection and cleaning of the tank, and before installing the insulation system,
the tank shall be tested by the Contractor for water tightness by filling the tank to its overflow elevation.
B. Any leaks discovered by this test shall be corrected by the Contractor in accordance with the tank
manufacturer’s recommendations.
Lowell Point Community Water System
13010 - 8
Bolted Steel Water Storage Tanks
C. The water required for this testing shall be provided by the Contractor at no charge to the Owner. The
water shall be of a reasonable quality and free of pollutants such that the test water does not compromise
the intended use of the tank. Disposal of the test water shall be the responsibility of the Contractor.
3.6
TANK DISINFECTION
A. Contractor shall disinfect the tank, in accordance with AWWA C652, after completion of all internal tank
components, installation of external valves and fittings and successful completion of leak testing.
B. Discharge of chlorinated water shall be in accordance with AWWA C652 and AWWA C652 Appendix C.
C. After disinfection is complete, the tank shall then be filled with potable water and placed into service.
3.7
WARRANTY
A. The Contractor shall warrant the tank against any defects in workmanship and materials for a period of two
years from the date of final acceptance.
B. In the event any such defect should occur, the Owner or Owner’s Representative shall report it in writing to
the Contractor during the warranty period.
END OF SECTION 13010
Lowell Point Community Water System
13010 - 9
Bolted Steel Water Storage Tanks