Technical Comparison Between Spiral Tanks & Moulded Tank

  Spiral Tank Moulded Tank
Material HDPE G M 1050 virgin HDPE / LDPE / other grade moulding
Material Characteristic Versatile material and can withstand many corrosive chemical at rough handling condition. Suitable for water storage
Manufacturing Technique
  • Spiral tank's shell is manufactured under fixed process parameters. Shell is manufactured by extrusion of strips and winding on the drawn.
  • Molecular orientation is on radial direction. Hence more Mechanical strength and no inbuilt stress.
  • Rotational moulding whereby mould is rotated under given speed and Molecular orientation is on Haphazard direction. Tank's shell is removed by sudden cooling, where by inbuilt stresses are developed.
Design
  • Tanks are designed as per service condition depending upon Corrosion, Hydraulic Stress Stirring speed and temperature. Thickness of tank is increases from Top to Bottom as Stresses are increased.
  • The sized of tanks are as per customers requirement.
  • Baffles Nozzles and stuffing box can be welded on Tank as per customer requirement with Extrusion welding.
  • Tanks are available in standard sized and in single thickness only.
  • Not possible
  • Not possible
Reparability Easily repaired at site by Extrusion Welding. Difficult to repair
Testing & Quality Tanks can be tested for welding at top and bottom in the same manner as steel tank. Main body is spirally wound and Mechanized wound Vertical open tank, Vertical closed tank. Will depend upon forming technique and Creep and cold flow can affect Dimension.
Type of Tanks Horizontal Tanks rectangular Tank Reaction Vessels with flanged top Conical bottom etc. Only limited type of Tanks are available Gas Tight Construction is not possible.