TUBE NEWS 2016 October | Page 23

different parameters in order to obtain a valid installation. The defined parameters are: Safety coefficient used in the calculation It does not meet the minimum security coefficient. Working pressure (bar): Pi The working pressure has been reduced considerably and has not reached an optimum result. Height of cover above pipe crown (m): H The height of cover has been modified and the safety coefficients are not satisfactory. Nominal pressure (bar) The calculation has been done with the smallest traffic load (LT12) and the safety coefficients are not satisfactory. The only option that is more favourable is an installation without concentrated traffic loads. Case where the selected installation has no concentrated traffic loads: The calculation has been done with the maximum nominal pressure (PN25) and the safety coefficients are not satisfactory. The installation has no concentrated traffic loads and the safety coefficients are not satisfied. Bedding angle (º): 2α Case where the selected installation has distributed The calculation has been done with the maximum traffic loads: bedding angle (180°) and the safety coefficients are not satisfactory. The installation has been calculated with distributed traffic loads and the safety coefficients Traffic are not satisfactory. Case where the selected installation has concentrated traffic loads: The TOM® Mechanical Calculation Program is accessible through the web application: www. tomcalculation.com 23 TN October 2016