Sigma FreeSpan

In operation and maintenance of high pressure gas pipelines the exposure of the pipeline is often necessary.
This App calculates the maximum allowable free span length and the resulting deflection for a pressurized onshore gas pipeline. Use this app e.q. if you excavate a pipeline for a renewal of the coating and you have to remove the oil underneath the pipeline.
Note that you have to bring the pipeline back into its original position before backfilling the trench to remove the axial stress. Please respect the safety rules for construction works!
The von mises equivalent stress resulting from internal pressure and dead weight of the pipeline is calculated. Maximum free span length is reached when von mises equivalent stress reaches the value of smys/safety factor. The safety factor is defined as reciprocal value of the load factor.The static system for calculating axial stress resulting from dead dead weight is assumed as a on both sides restrained (rigid) beam. Note that this App is only for users with expert knowledge and experience in high pressure piping systems.