For the first time RITA® offers a means of dimensioning tanks in conformity to the new supplementary sheets to DVS guideline 2205 with a conical and sloping bottom. At the same time the skirt and supporting structure for the bottom are calculated.
Openings in the cylinder up to 800 mm
In deviation from DVS Guideline 2205 RITA enables openings with a diameter of up to 800 mm in the cylinder. At the same time the user is given information about the permissible area in the cylinder where the opening may be located.
Roof structures and roof loads
The RITA® program distinguishes between roof structures which apply a load to the cylinder only and roof loads which act on the roof. Roof loads are entered as surface loads; for roof structures which are specified in N the program enables the number and width of the load application points to be specified and also takes into consideration traffic loads which may act for a short time on the cylinder edge during installation of roof structures.
For dimensioning lifting lugs RITA enablesthe weight of the roof structures to be applied only for dimensioning of the lifting lugs to be entered. This value cannot be greater than the weight of the roof structures.
Physical accessibility of flat roofs
When calculating a tank with a flat roof, the option is offered of making the roof physically accessible or not.
Adaptation of roof temperature for outdoor installation
Under DVS 2205 a roof temperature of 50 °C is allowed for the summer load condition of conical roofs for outdoor installation. Since, when installing in foreign countries, the roof temperature may be higher, RITA® enables this temperature to be raised to a maximum of 80 °C, depending on material.
Tanks in shell construction
In special cases, if bending of the sheets is no longer possible because of the required wall thickness, tanks must be manufactured double-walled. As a result, RITA® indicates the minimum thickness of the inner shell and minimum height of the reinforcement shell.
Manual adaptation of wall thicknesses
On the results side the minimum required wall thicknesses for the cylinder, bottom and roof are specified. These can be manually adapted and so optimised. Thus, for example, by increasing the wall thicknesses and so the overall weight the number of anchors required can be reduced. At the same time the required thickness of the lifting lugs would, if necessary, be automatically increased.
Where tanks are to be installed in areas of seismic activity, verification of earthquake protection is increasingly being required for them. Now RITA® offers a means of designing and anchoring cylindrical, flat-bottomed tanks so as to make them earthquake-resistant.
Residual filling height
Calculation of residual filling height through overpressure for flat- and sloped-bottomed tanks is done in RITA® in accordance withDVS 2205-2. If a required residual filling height of 30 mm is exceeded, the program emits a warning stating the required residual filling height for the given bottom thickness. If the bottom thickness is increased, the required residual filling height can be reduced. In cases of overpressure and indoor installation an option of anchoring the tank may be selected.
Under DVS 2205 verification is required that for the event of damage 0.9 times the weight of the tank is greater than the uplift of the immersed tank component. If it is not, RITA® emits a warning and enables e.g. the collecting diameter to be adjusted.