Composite Elevated Storage Tank (CET)
DEFINITION: An elevated welded carbon-steel water storage tank, supported by a steel-reinforced concrete support pedestal (extending vertically from the steel-reinforced foundation as a circular concrete support structure). The reinforced concrete pedestal features architectural, horizontal, and vertical rustication patterns formed into the exterior of the pedestal.
Standard Sizes : CET
- Overhead and personnel doors allow for secure access to the tank contents. Additionally, anti-graffiti coatings are available for the pedestal exterior. Composite Elevated Storage Tanks are generally used for the first 20 feet of concrete shaft.
- Depending on column diameter and the owner’s needs, Caldwell can furnish the shaft with an 8’ to 14’ wide overhead door for easy access. This makes it possible for the base of the shaft to provide for ample storage for valve assemblies, pumps, and equipment; or multi-purpose uses such as office space, storage, and possibly multiple floors with windows.
- A reinforced concrete pedestal support shaft offers ‘Severe Weather’ protection for nearby employees, personnel, or neighbors.
When It's Best
- Minimizes surface area for repainting operations
- Most modern style; some believe the most aesthetically pleasing and others feel the securest with least liability
- Utilized in areas where future repainting is either limited or more frequent (such as tight sites or aggressive environments)
- Most common and typically most economical style in capacities greater than 1,000,000 gallons
Highlights & Advantages
- Combining an efficient use of reinforced concrete for the support pedestal with welded steel for a watertight storage tank, the Composite Elevated Tank is an attractive, low maintenance, and durable structure.
- Gain cost efficiency in utilizing the valuable strength characteristics of each material; including the tensile strength of steel for the water containment vessel and the compressive strength of concrete as the support column for the tank.
- No coating system is required for the concrete shaft, which means less long-term maintenance (and reduced surface area for painting).
- Interior ladders and piping protect against weather and vandalism, all while easily allowing for pipe insulation.
- Two styles of typical roofs: Conical or Dome.
- Architectural Rustications highlight the concrete column. These rustications are placed vertically and horizontally at the edge of concrete forms, blending concrete appearance and hiding construction joints.
- Reference the table 250,000 to 3,000,000
- Steel frost-proof pressure/vacuum relief vent designed for maximum protection
- (1) roof hatch with hinged cover and hasp
- (1) roof hatch bolted for attachment of exhaust fan
- (1) access tube roof hatch
- (1) tank floor manhole
- (1) removable access hatch at top of supporting shaft
- (1) manhole in base of access tube
- (1) painter hatch at top of composite shaft
- Purchaser specified inlet/outlet piping with expansion joint
- Shaft-supported stainless steel overflow pipe to grade level with concrete splash pad
- All ladders, walkways, handrails and attachments inside the shaft are galvanized
- Rest seats and platforms at desired intervals
- Supporting shaft and access tube ladders with OSHA compliant safety climb devices
- Upper shaft walkway with OSHA compliant handrail
- Grounding for minimizing lightning damage
- Personnel door in base of supporting shaft
- Metal drip pan drain under access tube
- Gravel floor inside shaft
- Tank drain for washouts
- Larger diameter manholes, hatches, and access tube
- Complete internal seal welding
- Overhead rolling door with automatic closer
- Intermediate rest platforms with OSHA compliant handrails
- Roof handrail
- Aluminum or custom roof vent
- Cellular antenna supports and provisions
- Painted logo, lettering, and custom graphics
- FAA lighting
- Insulated tank piping
- Piping in base of shaft - bypass lines, altitude valve, service pumps, etc.
- Additional free-span floors
- Masonry block building in base of shaft
- Overflow flap valve
- High water elevation/pressure gauge
- Concrete floor inside shaft
- Instrumentation, control room, & cathodic protection
- Solar powered or other type of mixing system
- Additional security or ornamental lighting
- Specialty trim or customized design