ALSTOR
INTERNATIONAL, INC.
STAINLESS STEEL
TANK SPECIFICATION
BOLTED
STAINLESS STEEL WASTEWATER STORAGE TANK
1.0
GENERAL:
1.1
SCOPE OF WORK:
Supply and erect a bolted stainless steel wastewater
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:
A. The bidder shall offer a new tank structure as supplied from a manufacturer specializing in the
design, fabrication and erection of factory fabricated, bolted stainless steel tank system.
B. Strict adherence to the standards of design, fabrication, erection, product quality and long term
(30 year minimum) performance, established in this specification will be required by the Owner
and Engineer.
C. The tank shown of the Contract Drawings and specified herein is a Tank System as manufactured
by Alstor International, Inc.
D. Alternate stainless steel tank products, as provided by other manufacturers, will be considered
for pre-bid approval by the Engineer. Pre-bid approval submissions must be made
no later than 21 days prior to the advertised project bid date.
E. Tank suppliers wishing to pre-qualify shall submit the following to the
Engineer/Owner for consideration no later than 21 days prior to bid date.
1. Typical structure and foundation drawing(s).
2. List of tank materials, appurtenances and tank specifications.
3. List of five (5) tanks presently in service, of size and character specified herein, including
the name and telephone number of Owner and Engineer.
4. Certification from tank manufacturer that tank meets all of tank design standards as listed
per Engineer’s specifications.
F. The Owner’s decision or judgment on any of the experience or qualification matters will be
final, conclusive, and binding.
1.3
REFERENCE SPECIFICATIONS:
The following reference specifications shall govern the work with regard to design materials and workmanship, where applicable.
ASTM A36 - Standard specification for structural steel.
ASTM A307 - Specification for carbon steel bolts.
ASTM A325 - Specification for high strength bolts.
ASTM A240 - Specification for chromium-nickel stainless steel plate and sheet.
AISC - 89 - Specification for structural steel buildings.
And if required:
ANSI/AWWA D103 – 97 Section 3, General design.
ANSI/AWWA D103 – 97 Section 5, Appurtenances as adapted for stainless steel.
ANSI/AWWA D103 – 97 Section 13, Structurally supported aluminum dome.
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 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:
_____________________
Finished Floor Elevation:
_____________________
2.2
DESIGN STANDARDS:
The design of the bolt-together tank shall conform to
AISC allowables.
2.3
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 type 304 stainless steel.
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:
Wind stiffener at top of tank shall provide a flat,
horizontal, continuous surface at tank rim level, compatible with geodesic dome
or roof mounting and flashing. Design
requirements for intermediate horizontal wind stiffeners shall be of the
"web truss" design. Wind
stiffeners shall be galvanized steel.
3.4
BOLT FASTENERS:
Bolts used in tank lap joints shall be stainless
steel 1/2 - 13
UNC-2A rolled thread.
Lap joint bolts shall be installed such that the head
portion is located inside the tank and the washer and nut are on the exterior.
Lap joint bolts shall be properly selected such that threaded portions
will not be exposed in the "shear plane" between tank sheets.
Bolt lengths shall be selected to achieve a neat and uniform appearance.
Excessive threads extending beyond the nut after tightening is not
acceptable.
Lap joint bolts shall include a minimum of two
splines on the underside of the bolt head at the shank in order to resist
rotation during tightening.
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 flex 1A.
4.0
APPURTENANCES:
The appurtenances shall be installed as shown on the Engineers drawings and as
detailed in these specifications.
4.1
GRAVITY VENT:
A gravity vent shall be installed at the center of
the roof.
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 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" 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 tank bottom and at the location designated.
Outside ladder and cage shall meet OSHA requirements.
The ladder shall be aluminum and the 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 type 304 or 316
stainless steel and meet OSHA requirements.
4.5
ACCESS MANWAY:
One 24" 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 type 304 stainless steel.
4.6
INLET AND OUTLET CONNECTIONS:
Inlet and outlet connections shall conform to the
sizes and locations specified on the Engineer's drawings.
Where connections are shown to pass through tank
panels, they shall be field located and utilize an interior and exterior flange
assembly. Sika flex 1A joint
sealant shall be applied to any cut panel edges or bolt connections.
Inlet and outlet connections shall be type 304
stainless steel.
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 stainless 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
IDENTIFICATION NAMEPLATE:
The Manufacturer's nameplate shall list the tank
diameter, height, capacity, installation date, storage 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 stainless steel floor is available as an option to the
reinforced concrete floor.
5.1
CONSTRUCTION:
The bolted floor construction would include sectional
bolted stainless steel floor panels as produced by the tank manufacturer.
The floor shall be erected similar to the sidewall panels using the same
sealant and bolting techniques. The
bolted floor shall be supported by compacted sand or placed upon a concrete
sub-floor. If a concrete sub-floor is utilized, a 1 inch thick layer of
fibercane shall be placed on the concrete floor prior to placement of the bolted
steel floor.
6.0
BOLTED ROOF:
Bolted
stainless steel roofs are available for tank diameters up to 36'.
6.1
CONSTRUCTION:
The roof shall be constructed of radially sectioned,
bolted stainless 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 foot diameter shall be supplied with aluminum dome
roofs.
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 loads.
8.0
ERECTION:
8.1
FOUNDATION:
The tank foundation shall be designed by the
Manufacturer based on the soil bearing capacity as tested and
determined by the Owner. Copies of
the soil 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 stainless 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 to
bottom plates or sheets shall be field bolted. Sika flex 1A sealant shall be used on all joints to ensure
liquid tightness. Fillet Sika flex
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
9.1
HYDROTEST:
The tank shall be hydrotested to ensure liquid
tightness by filling the tank to its overflow elevation.
Water and disposal of as required for this test shall
be the responsibility of the Owner.
10.0
WARRANTY:
10.1 STRUCTURES:
date of delivery of the product to the site upon which it is to be erected) the water 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.
Manufacturer shall further warrant that, if within a period of five (5) years from the date of
completion the stainless steel sheets placed in the storage tank fail due to corrosion
as determined upon examination by the manufacturer, the manufacturer will supply
replacement sheets F.O.B. the manufacturer's factory, or the manufacturer, at its option
will repair or allow credit for such sheets.