With over a century in tank design & field erection, we’ve continually developed and critiqued our design and construction process, producing a safer and longer lasting tank. Some design specifics considered include:
Roof Types Section
Configuration
Internal Floating Roof (IFR)
Summary
Column / Structurally Supported Cone Roof
A common fixed-roof design for tanks with relatively low pressure. They contain a shallow cone roof utilizing a center column of pipe or structural steel. Intermediate columns are commonly used on larger diameter tanks. Internal framing is used to support the roof plates; this may include supporting rafters, clips, tie bars and girders. A frangible roof joint may be designed for added protection in the event of a sudden increase in internal pressure.
Highlights
- Permits for a large diameter roof design
- Roof can be sealed and VRU can be used
- Rigid structure can be designed for large snow loads
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment.
- No deck drain required on internal floaters.
Summary
Column / Structurally Supported Cone Roof
A common fixed-roof design for tanks with relatively low pressure. They contain a shallow cone roof utilizing a center column of pipe or structural steel. Intermediate columns are commonly used on larger diameter tanks. Internal framing is used to support the roof plates; this may include supporting rafters, clips, tie bars and girders. A frangible roof joint may be designed for added protection in the event of a sudden increase in internal pressure.
Highlights
- Permits for a large diameter roof design
- Roof can be sealed and VRU can be used
- Rigid structure can be designed for large snow loads
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Summary
Column / Structurally Supported Cone Roof
A common fixed-roof design for tanks with relatively low pressure. They contain a shallow cone roof utilizing a center column of pipe or structural steel. Intermediate columns are commonly used on larger diameter tanks. Internal framing is used to support the roof plates; this may include supporting rafters, clips, tie bars and girders. A frangible roof joint may be designed for added protection in the event of a sudden increase in internal pressure.
Highlights
- Permits for a large diameter roof design
- Roof can be sealed and VRU can be used
- Rigid structure can be designed for large snow loads
Internal Floating Roof
None selected
Configuration
Internal Floating Roof (IFR)
Externally Stiffened
Summary
Self-Supporting Cone
Suitable for small diameter tanks. Roof is supported at the shell.
Highlights
- Roof can be sealed
- No internal columns, eliminating opportunities for corrosion and hang-ups during operation
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
Summary
Self-Supporting Cone (Externally Stiffened)
Suitable for medium size diameter tanks. The external stiffening can allow additional support for platforms and structures on the roof.
Highlights
- Suitable for tanks with internal roof coating
- External Stiffening allows for a medium sized roof diameter
- Roof can be sealed and VRU can be used
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
Externally Stiffened
Summary
Self-Supporting Cone
Suitable for small diameter tanks. Roof is supported at the shell.
Highlights
- Roof can be sealed
- No internal columns, eliminating opportunities for corrosion and hang-ups during operation
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Summary
Self-Supporting Cone (Externally Stiffened)
Suitable for medium size diameter tanks. The external stiffening can allow additional support for platforms and structures on the roof.
Highlights
- Suitable for tanks with internal roof coating
- External Stiffening allows for a medium sized roof diameter
- Roof can be sealed and VRU can be used
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Externally Stiffened
Summary
Self-Supporting Cone
Suitable for small diameter tanks. Roof is supported at the shell.
Highlights
- Roof can be sealed
- No internal columns, eliminating opportunities for corrosion and hang-ups during operation
Internal Floating Roof
None selected
Summary
Self-Supporting Cone (Externally Stiffened)
Suitable for medium size diameter tanks. The external stiffening can allow additional support for platforms and structures on the roof.
Highlights
- Suitable for tanks with internal roof coating
- External Stiffening allows for a medium sized roof diameter
- Roof can be sealed and VRU can be used
Internal Floating Roof
None selected
Configuration
Internal Floating Roof (IFR)
Externally Stiffened
Summary
Self-Supporting Umbrella
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- Roof can be sealed and VRU can be used
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
Summary
Self-Supporting Umbrella (Externally Stiffened)
Externally stiffened umbrella roofs are used on large diameter tanks. The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost.
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- External Stiffening allows for a large sized roof diameter
- Roof can be sealed and VRU can be used
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
Externally Stiffened
Summary
Self-Supporting Umbrella
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- Roof can be sealed and VRU can be used
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Summary
Self-Supporting Umbrella (Externally Stiffened)
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost.
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- Roof can be sealed and VRU can be used
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Externally Stiffened
Summary
Self-Supporting Umbrella
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost.
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- Roof can be sealed and VRU can be used
Internal Floating Roof
None selected
Summary
Self-Supporting Umbrella (Externally Stiffened)
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost.
Highlights
- Can often be built from thinner material than a cone
- The bulk of the roof work can take place at grade
- Suitable for tanks with internal roof coating
- Roof can be sealed and VRU can be used
Internal Floating Roof
None selected
Configuration
Internal Floating Roof (IFR)
Summary
Geodesic Dome
These clear-span, space frame structures are corrosion-resistant, easy to maintain, and customizable.
Highlights
- They are Light weight
- Naturally corrosion resistant. No coatings required
- No internal columns or penetration of floating roofs needed
- Emissions reduction
- Can be constructed either on tank or elsewhere on site
Internal Floating Roof (Carbon Steel)
Under the fixed-roof tank, an internal floating-roof is commonly used for the storage of many petroleum and chemical products. TIW custom designs single and double deck variations constructed of welded steel. The internal floating roof provides an effective and practical means of reducing vapor emissions from stored volatile liquids. Rim seal systems seal the space between the floating deck and tank shell. Additional seals are installed around each column.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
Summary
Geodesic Dome
These clear-span, space frame structures are corrosion-resistant, easy to maintain, and customizable.
Highlights
- They are Light weight
- Naturally corrosion resistant. No coatings required
- No internal columns or penetration of floating roofs needed
- Emissions reduction
- Can be constructed either on tank or elsewhere on site
Internal Floating Roof (Aluminum)
A single light aluminum deck serves as a horizontal membrane that moves up and down to reduce vapour loss. Vents in the roof allow the tank to operate at atmospheric pressure. Seals are installed around each column as well as around the periphery of the floating roof.
Highlights
- Internal floating roof (IFR) is protected from the environment
- No deck drain required on internal floaters
- Aluminum floaters are light weight and relatively easy to install
- Small panels are replaceable over time
- Can be cable supported. i.e no deck legs required
- Maintenance and operating heights can be adjusted with cables outside of the tank during operation
- Coating is not required on the floating deck
Summary
Geodesic Dome
The umbrella roof consists of a modified dome, where the horizontal section is a regular polygon with multiple sides with roof plates, supported only at the periphery. Dome roofs are also possible at a higher cost.
Highlights
- They are Light weight
- Naturally corrosion resistant. No coatings required
- Emissions reduction
- Can be constructed either on tank or elsewhere on site
Internal Floating Roof
None selected
Summary
Open Top Floater
These tanks are commonly found in terminals across Canada, and are used for storing bulk quantities of petrochemicals. These tanks come in a large range of sizes with diameters ranging from 20’ to 350’.
Highlights
- Simple design
External Floating Roof
- Easy access with rolling ladder
- Highly customizable
- Safe for maintenance as you can easily walk on the floating deck
Design Specifics
Considerations
- Allowable external Loads on tank shell openings
- Internal & external Pressures
- Environmental loads (wind, seismic, snow, importance factors)
- Foundation design
- Design based on tanks operating at elevated temperatures
- Design based on tanks operating at lower temperatures
- Single or double bottoms
Requirements
- Product conditions
- Maximum capacity
- Secondary containment
- Internal or external floating roofs
Materials of Construction
- Carbon steel, stainless steel or duplex steel
Corrosion Protection
- Linings, coatings, wallpapering
- Cathodic protection
Access Systems
- Floating roof access options
- Radial or spiral stairways
- Roof access systems
Heat Conservation
- Various insulation products
Product Gallery
Appurtenances
Our design engineers can customize a wide range of appurtenances on the interior and exterior of your tank. At our in-house, 200,000 sq ft material processing plant, we fabricate everything from pontoons, nozzles, vents and piping to custom stairways, platforms and rolling ladders.
Here are some typical components we design, fabricate and install on our API 650 tanks…
Internal Components
- Integrated Liquid Level Gauges and Gauge Poles
- Heating Coils
- Baffles
- Piping Subsystems for Multi-Level Sampling
- Overflow
- Draw-Off
- Diffusers
- Pumping
Steel Floating Decks
- Single & Double Deck Floating Roofs with Legs & Components
- Deck Drains & Sumps
- Internal Rolling Ladders
External Attachments
- Nozzles (with flanges, elbows, couplings and more)
- Ladders, Spiral and Radial Stairways:
- Single and Double Stringer Designs with Handrail Variations
- Roof Walkways, Platforms and Joining Catwalks
- Flush Cleanout Manways, Shell Manways and Mixer Manways
- Rectangular and Circular Hatches
- Fire Protection Foam Piping
- Wind Girders (with railings)
- Insulation Rings
- Lightning Arrestors
- Rescue Davits
- Shell Vents, Circulation Vents
- Piping Supports, Cable Support Trays and Grounding Lugs
API 650 Standard
TIW designs tanks to both API 650, API 620 and AWWA D-100, each having its place depending on the specific requirements of the product being stored. API 650 is the most common standard for tanks that store oil, gasoline, chemicals and process water.
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API 650 Standard
Requirement
The American Petroleum Industry (API) has established the 650 standard, setting minimum requirements for the design, material, construction, and testing of aboveground, open and closed-top, cylindrical welded steel storage tanks of various capacities and sizes.
They are designed as non-refrigerated tanks with a minimum material thickness of 3/16 inch of carbon steel, austenitic duplex stainless steel, and aluminium. Supporting an internal pressure of 2 ½ PSI or less and an operating temperature of -40°F to 500°F. They are commonly used to store products such as crude oil, petroleum by-products, chemicals and process water.
Typical Usage
- Crude Oil
- Refined Gases
- Biofuels
- Process Water
- Sulfur
- Chemicals
Repairs, Modifications & Testing
The API 650 Standard provides details for the minimum testing to be performed to ensure quality workmanship of the tank along with a separate standard, API 653, dedicated to providing a complete set of procedures and tests, specifically for the repair of API 650 tanks.
We are well-known for our expertise in performing repairs and modifications for a wide range of customers. Please see our API 653 Repair Services for more details.
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API 620 Standard
Requirements
The API 620 Standard governs the design and construction of large, welded, low-pressure storage tanks. These tanks require an elevated, flat or cone bottom, and a minimum material thickness of 3/16 of an inch in carbon steel, austenitic stainless steel and nickel alloys (low temperature only). These tanks operate as low as -325°F to 250°F with an operating pressure of up to 15 PSI. They are generally utilized for cryogenic liquefies such as LOX, LIN or LNG as well as other chemicals which require internal design pressures exceeding those allowed by 650 tanks.
Typical Usage
- Liquid Oxygen (LOX)
- Liquid Argon (LAR)
- Liquid Nitrogen (LIN)
- Liquified Natural Gas (LNG)
- Natural Gas Liquids (NGL)
- Liquified Propane (LPG)
- Compressed Natural Gas (CNG)
- Anhydrous Ammonia (AA)
- Acidic Chemicals
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AWWA D-100 Standard
Requirement
The American Water Works Association has set these guidelines for the construction of welded carbon steel tanks for water storage. The American National Standards Institute has adopted them as best practices within the industry for designing and building tanks to be used in water systems where the internal pressure does not exceed atmospheric pressure.
Typical Usage
- Potable Water Storage
- Firewater Storage
Managed Services
Protective Coatings & Insulation
Given the diversity of the stored products and their chemical properties, there are a wide variety of protective coating options that we can provide for corrosion prevention. TIW can offer a variety of external coatings, full or partial internal lining, vapour space coating and application of custom decals.
We also offer alternate corrosion options such as hot dip galvanizing, coating over galvanized components and fireproof coating.
Shop Pre-Coating
TIW can shop coat floor plates, shell plates, appurtenances, floating deck plates and pontoons prior to shipping to site. This can help offset the high prices of field coating and help minimize open-air blasting which can be environmentally prohibited in some project locations.
Galvanizing
We provide galvanizing of various tank components – from nozzles, piping and support clips to handrails, ladders and platforms. In some cases, both galvanizing and coating are applied providing a superior protection.
Exterior Coatings
These coatings are applied to the exterior of tanks or vessels for corrosion protection and cosmetic appearance. Some typical coatings we use include:
- High-performance epoxy primers and finish coatings
- Inorganic zinc coatings
- Holding primers
- Acrylic polyurethane coatings
- High-temperature coatings
Interior Linings
The interior surfaces of these tanks are typically lined with a submersion grade epoxy lining, from the floor to 1 meter up the shell (in oil tanks), whereas the interiors of water or other process tanks may be completely coated. TIW removes all sharp edges before sandblasting any area, and can perform complete Holiday testing (to test for voids in the liner), prior to signing off on the lining. Typical linings used include:
- Epoxy primers
- Epoxy finish coatings
- High temperature coatings
Insulation
When temperature control is required per design, TIW can supply and install a variety of mechanical insulation to meet the customer’s requirements. Insulation options can vary from the more common insulation batts with external cladding to prefabricated insulated panels. There are also different insulation and cladding material options. Depending on design and temperature requirements, TIW can offer several insulation materials such as
- Fiberglass
- Calcium silicate
- Mineral wool
- Cellular glass
- Perlite
- Polyisocyanurate
- Thin blanket
- Aerogel