Fluted Column Elevated Storage Tank (FLC)

DEFINITION: An elevated welded carbon-steel water storage tank supported by a single large diameter corrugated carbon-steel support column.

Positive Uses (when it's best)

  • Largest capacity tanks constructed in the industry to-date
  • To gain additional storage capacity in the water system (especially for fire protection)
  • To gain additional pressure in the water system (especially for power outages)

Highlights & Advantages (over other styles)

  • The massive tank is geometrically well proportioned with a conical and dished bottom, vertical shell, and dome shaped roof yielding this style of tank to accept large decorative logos to be painted on the tank and column promoting the communities or blending it in with its environment
  • The large diameter, all steel single support column is fluted to combine greater structural rigidity with an architecturally pleasing appearance and geometrically well-proportioned structure
  • Caldwell's Fluted Column Tank has interior ladders and piping which protects them against weather and vandalism and easily allows for pipe insulation

Special Features (bonus part of asset)

  • The column can be furnished with a 10' or 12' wide (depending on column diameter and the owner's needs) overhead door for easy access making it possible for the base area of the column to have multi-purpose uses such as ample storage for equipment, water treatment systems, pumps, freeze protection systems, and valve assemblies, office space, and the easiest access to multiple floors with possible spiral stairs, hoisting cranes, and elevators.
  • All-steel construction offers endless specialty paint designs and 'neighbor-approved' logos.

Standard Sizes (others available but may be at a premium)

  • Reference the table 500,000 to 3,000,000

Standard Accessories
American Water Works Association (AWWA D100 & D102)

  • Steel frost-proof pressure/vacuum relief vent designed for maximum protection
  • (1) 24" diameter roof hatch with hinged cover and hasp
  • (1) 24" diameter roof hatch bolted for attachment of exhaust fan
  • (1) 24" diameter access tube roof hatch
  • (1) 18" x 24" diameter manhole in base of access tube
  • (1) 18" x 24" diameter manhole in bottom of tank
  • ¬†(2) 24" diameter painter hatch at top of fluted column
  • Purchaser specified inlet/outlet piping with expansion joint
  • Pedestal-supported overflow pipe to grade level with concrete splash pad
  • Fluted column and access tube ladders with OSHA compliant safety climb devices
  • Rest platforms at each column stiffener with OSHA compliant handrail
  • Upper column ¬†walkway with OSHA compliant handrail
  • Painter's rings near top of column
  • Interior lighting in column and in access tube
  • Grounding for minimizing lightning damage
  • Personnel door in base of supporting column
  • Gravel floor inside column

Elective Accessories
Collective in the Water Tank Industry

  • Tank drain for washouts
  • Larger diameter manholes, hatches, and access tube
  • Condensate ceiling (fabric or steel with a drain to the overflow pipe)
  • Complete internal seal welding
  • Overhead rolling door with automatic closer
  • Roof handrail
  • Aluminum or custom roof vent
  • Cellular antenna supports and provisions
  • Painted logo, lettering, and custom graphics
  • FAA lighting
  • Insulated tank piping
  • Stainless Steel piping
  • Piping in base of column- bypass lines, altitude valve, service pumps, etc.
  • Additional free-span floors
  • Metal/Wood studded building in base of column
  • Overflow flap valve
  • High water elevation/pressure gauge
  • Concrete floor inside column
  • Instrumentation, control room, & cathodic protection
  • Solar powered or other type of mixing system
  • Additional security or ornamental lighting
  • Specialty trim or customized design

Specifications & Standard Tank Drawing

Caldwell Drawings & Specs

Standard Sizes : FLC

(US Gallons)
Head Range
Tank Diameter
Pedestal Diameter
250,000 30' 42' 25'
300,000 32' 44' 25'
400,000 39'6" 46' 25'
500,000 38' 50' 30'
500,000 30' 58' 34'
750,000 40' 64' 42'
1,000,000 40' 74' 52'
1,000,000 35' 80' 52'
1,500,000 42' 86' 60'
1,500,000 35' 96' 60'
2,000,000 42' 96' 72'
2,500,000 44'6" 104' 78'
3,000,000 42' 120' 90'

Surveys from Actual Caldwell Tank projects

Case Studies for Actual Caldwell Tank projects

Caldwell Connect