NBN EN 12573-3 : 2000

Foreword
1 Scope
2 Normative references
3 Definitions, symbols and abbreviations
      3.1 Definitions
      3.2 Symbols and abbreviations
4 General considerations in design calculations
5 Unstiffened tanks sitting on a continuous flat
      rigid surface
      5.1 General
      5.2 Aspect ratio x/y < 0,5
      5.3 Aspect ratio 0,5 < x/y < 4
      5.4 Aspect ratio x/y > 4
6 Tanks with rim stiffening supported on a continuous
      flat rigid surface
      6.1 Calculation of the skin thickness
      6.2 Calculation of rim stiffeners
7 Tanks with intermediate horizontal stiffeners
      supported on a continuous flat rigid surface
      7.1 General
      7.2 Calculation of the minimum skin thickness
      7.3 Calculation of the horizontal stiffeners
8 Tanks with cross-ribbed horizontal and vertical
      stiffeners supported on a continuous rigid surface
      8.1 Calculation of the minimum skin thickness,
             base thickness and properties of horizontal
             stiffeners
      8.2 Calculation of the properties of vertical
             stiffeners
9 Rectangular tanks with U-frame
      9.1 General
      9.2 Calculation of the skin thickness of the side
             walls
      9.3 Determination of the tank base
      9.4 Calculation of the U-frame stiffening
10 Determination of the tank cover
      10.1 General
      10.2 Freely supported tank cover
      10.3 Fixed tank cover
      10.4 Stiffened tank cover
Annex A (informative) Construction details for rectangular
                      tanks
Annex B (informative) Special cases
Annex C (informative) A-deviations
Bibliography

Defines the design and calculation for single skin rectangular tanks, fabricated from the following thermoplastics: Polyethylene (PE), Polypropylene (PP), Poly (vinyl chloride) (PVC), Poly (vinylidene fluoride) (PVDF). Tanks may be strengthened on the outside by means of ribs or frames made of the same or other materials. Only applies to tanks not intended to withstand internal pressure or vacuum, other than that which may occur during the transfer of fluids (including gases) in their normal operation.