ALSTOR
INTERNATIONAL, INC.
SPECIFICATION
BOLTED
GALVANIZED CARBON STEEL LIQUID STORAGE TANK
1.0
GENERAL
1.1
SCOPE
OF WORK:
Supply and erect a bolted galvanized steel liquid
storage tank, including foundation, tank cover, tank structure, and tank
appurtenances as shown on the Engineer's drawings, and described herein.
All labor, materials, equipment, tools etc., as required for the
construction of the storage tank shall be included.
1.2
QUALIFICATION
OF TANK SUPPLIER:
The bidder shall offer a new tank structure as
supplied from a manufacturer specializing in the design, fabrication, and
erection of factory fabricated, bolted galvanized steel tank systems.
1.3
REFERENCE
SPECIFICATIONS:
The following reference specifications shall govern
the work with regard to design, materials, and workmanship, where applicable.
ACI 301 -
Standard specification for structural
concrete.
ANSI/ASTM A36 -
Standard specification for carbon structural steel.
ANSI/ASTM A123 - Hot dip galvanized coatings on iron
and steel products.
ANSI/ASTM A153 - Hot dip galvanized coatings on iron
and steel hardware.
ANSI/ASTM A307 - Specification for
carbon steel bolts.
ANSI/ASTM A325 - Specification for
high structural bolts.
ANSI/ASTM A490 - Specification for
heat-treated structural bolts.
ANSI/ASTM A570 - Specification for hot-rolled carbon steel sheets.
ANSI/ASTM A572 - Specification for
high-strength carbon steel sheets.
ANSI/ASTM A607 - Specification for
high-strength carbon steel sheets.
ANSI/ASTM A715 - Specification for
high-strength carbon steel sheets.
AISC-ASD -
Specification for structural steel buildings.
1.4
SUBMITTAL
DRAWINGS AND CALCULATIONS:
Construction shall be governed by the Owner's plans
and specifications showing general dimensions and construction details, after
approval by the Engineer of submittal drawings and design calculations prepared
by the Manufacturer.
There shall be no deviation from these drawings and
specifications, except upon written order or approval from the Engineer.
The bidder is required to furnish for review and approval by the
Engineer, construction drawings for all work not shown in complete detail on the
bidding drawings. A complete set of
structural calculations shall be provided for the tank structure and foundation.
All such submissions shall be stamped by a Registered
Professional Engineer.
When approved, two (2) sets of such prints and
submittal information will be returned to the bidder marked "APPROVED FOR
CONSTRUCTION" and these drawings will then govern for the work detailed
thereon.
2.0
DESIGN
2.1
TANK
SIZE AND CAPACITY:
Nominal Diameter:
___________________________
Sidewall Height:
___________________________
Nominal Capacity:
___________________________
High Water Elevation: ___________________________
Finished Floor Elevation: ___________________________
2.2
DESIGN
STANDARDS:
The design of the bolt-together tank shall conform to
AISC allowables.
2.3
DESIGN
FEATURES:
Tank shall be designed in such a manner that the
primary vertical seams shall be in line from top to bottom of tank.
This design shall incorporate a bolt at the corner of each plate
intersection to eliminate the "potential leak path".
2.4
DESIGN
LOADS:
Roof Snow Load:
___________________________
Roof Live Load:
___________________________
Wind Load:
___________________________
Allowable Soil Bearing Capacity:
___________________________
Earthquake Seismic Zone:
___________________________
Specific Gravity of Tank Contents: ___________________________
3.0
MATERIAL
3.1
PLATES
AND SHEETS:
Plates and sheets used in the construction of the
tank shall be zinc coated steel (hot dip galvanized).
Design requirements for mild strength steel shall be
ASTM A570 Grade 30, 36, or 40.
Design requirements for high-strength steel shall be
ASTM A572 Grade 50, 60, or 70, ASTM A607 Grade 50, 60, or 70, ASTM A715 Grade
50, 60, or 70.
3.2
ROLLED
STRUCTURAL SHAPES:
Rolled structural shapes shall be galvanized steel.
Material shall conform to minimum standards of ASTM A36.
3.3
HORIZONTAL
WIND STIFFENERS:
Horizontal wind stiffeners shall be galvanized steel.
Design requirements for horizontal wind stiffeners shall be of the
"web truss" design.
Material shall conform to minimum
standard of ASTM A36.
3.4
BOLT
FASTENERS:
Bolts used in tank lap joints shall be 1/2 - 13
UNC-2A rolled thread with galvanized coating.
3.5
SEALANT:
The lap joint sealant shall be a one component
moisture cured polyurethane compound.
The sealant shall be used to seal lap joints and bolt
connections and to isolate dissimilar metals.
The sealant shall cure to a rubber-like consistency and have excellent adhesion, have low shrinkage,
and be suitable for interior
and exterior exposure.
Neoprene gaskets and tape type sealer shall not be
used.
The sealant shall be Sika 1A.
4.0
APPURTENANCES
The appurtenances shall be installed as shown on the Engineer's drawings and as detailed in these
specifications.
4.1
GRAVITY
VENT:
A gravity vent shall be installed above the
high-water level adjacent to the access hatch near the tank rim for ease of
access for inspection.
The vent shall be sized to ensure positive or
negative pressure will not be developed which would exceed 1/2" WC,
considering the maximum possible flow rate of water to fill or withdrawal.
The overflow pipe shall not be considered to be a
vent.
The vent material shall be aluminum.
4.2
ROOF
HATCH:
A roof hatch shall be installed in the tank roof.
The hatch opening shall have a minimum dimension of 24 inches and the
cover hinged with provisions made for locking.
The hatch material shall be galvanized steel.
The hatch shall be located near the outside tank
ladder.
4.3
OUTSIDE
TANK LADDER:
An outside ladder with safety cage shall begin 6 feet
above the level of the tank bottom and at the location designated.
Outside ladder and cage shall meet OSHA requirements.
The ladder and cage material shall be galvanized
steel.
4.4
INSIDE
TANK LADDER (OPTIONAL):
An inside tank ladder, if required, shall be
installed below the roof hatch and shall be fabricated of galvanized steel and
meet OSHA requirements.
4.5
ACCESS
MANWAY:
One 24 inch diameter manway shall be provided at a
location to be determined by the Engineer.
The manway shall include a reinforcing frame and cover plate with a
hinged support for cover removal. The
manway material shall be galvanized steel.
4.6
INLET
AND OUTLET CONNECTIONS:
Inlet and outlet connections shall conform to the
sizes and locations specified on the Engineer's drawings.
4.7
OVERFLOW
PIPE:
The overflow pipe shall conform to the size and
location specified on the Engineer's drawings.
Overflow pipe shall be Schedule 80 PVC.
4.8
ROOF
WALKWAY AND HANDRAILS:
For tanks with a bolted galvanized steel roof, a
non-skid roof walkway with handrails shall be provided to allow ready and safe
access to the gravity vent. The walkway and handrails shall be galvanized steel
and meet OSHA requirements.
4.9
CATHODIC
PROTECTION:
Supply a passive sacrificial magnesium anode cathodic
protection system.
Electrical continuity between all tank sidewall or
floor panels to be the responsibility of the Tank Manufacturer.
4.10 IDENTIFICATION NAMEPLATE:
The Manufacturers' nameplate shall list the tank diameter, height,
capacity,
use and model/serial number. The nameplate shall be bolted to the tank shell at an elevation such
that it can be viewed from grade.
5.0
BOLTED FLOOR - (OPTIONAL)
A bolted galvanized steel floor is available as an option to the
reinforced
5.1
CONSTRUCTION:
The bolted floor construction would include sectional
bolted galvanized steel panels as
produced by the Tank Manufacturer. The floor shall be erected similar to the sidewall panels
using the same sealant and bolting techniques.
Typically, the floor shall be supported by compacted sand or fiber cane
mat depending on the application.
Nuts, caps, and sealant shall be used to cover the
bolts, nuts, and washers exposed on the inside of the floor.
6.0
BOLTED ROOF
Bolted galvanized steel roofs are available for tank diameters up
to 36 feet.
6.1
CONSTRUCTION:
The roof shall be constructed of radially sectioned,
bolted galvanized steel roof panels as produced by the Tank Manufacturer.
The roof panels shall be erected similar to the
sidewall panels using the same sealant and bolting techniques.
The roof shall be self-supporting and shall clear the span of the tank.
The roof shall transfer the live and dead loads to the sidewall.
7.0
ALUMINUM DOMED ROOF
Tanks greater than 36 feet diameter shall be supplied with aluminum dome roof as an option.
7.1
CONSTRUCTION:
The dome shall be constructed of non-corrugated
triangular aluminum panels on a fully triangulated aluminum space truss system
of wide flange extrusions, thus forming a spherical dome structure.
The dome shall be clear span and designed to be
self-supporting from the periphery structure with primary horizontal thrust
contained by an integral tension ring. The
dome dead weight shall not exceed 3 pounds per square foot of surface area.
The dome and tank shall be designed to act as an
integral unit. The tank shall be
designed to support an aluminum dome roof including all specified live loads.
8.0
ERECTION
8.1
FOUNDATION:
The tank foundation shall be designed by the
Manufacturer based on minimum 2000 psf soil bearing capacity or greater as
determined by the Owner. Copies of
the soils report shall be provided by the Engineer to the Manufacturer prior to
bid.
8.2
CONCRETE
FLOOR:
The standard floor design is of reinforced concrete
with an embedded galvanized steel starter ring.
8.3
STARTER
RING:
The starter ring shall be leveled and rounded prior
to encasement in concrete. A
leveling plate assembly shall be used to secure the starter ring.
Prior to placement of concrete, butyl rubber and
bentonite water stop seals shall be placed on the inside surface of the starter
ring below the concrete floor line. These
materials shall be installed as shown on the construction drawings.
8.4
LAPPED
JOINTS:
All vertical, horizontal, shell to roof, and shell
plates or sheets shall be field bolted. Sika
1A sealant shall be used on all joints to ensure liquid tightness.
Fillet Sika 1A sealant at all lapped joints to provide a neat and
pleasing appearance.
8.5
SIDEWALL:
Placing of sealant on each connection may be
inspected by the Engineer prior to placement of adjacent member.
However, the Engineer's inspection shall not relieve the Erector of his
responsibility for liquid tightness.
9.0
LEAK TEST
Leak test shall not take place until joint sealant is fully cured (10 to
12 days at 73 degrees F).
9.1
HYDROTEST:
The tank shall be tested to ensure liquid tightness
by filling the tank to the overflow elevation.
Water and disposal of as required for this test,
shall be the responsibility of the Owner.
10.0
WARRANTY
10.1 STRUCTURES:
If within a period of one (1) year from date of completion (but not more than 14 months
from date of delivery of the product to the site upon which it is to be erected) the liquid
storage tank, or any part thereof, proves to be defective in material or workmanship upon
examination by the Manufacturer, the Manufacturer will supply replacement part F.O.B.
the Manufacturer's factory, or the Manufacturer, at its option will repair or allow credit
for such part.