The total lifetime of a pipeline segment is limited and depends on operational procedures. In order to predict material fatigue it is important to monitor the stress that is caused by pipeline pressures. If most pump operations are performed during steady state with only a few interruptions, the impact on the total lifetime is much less than during transient conditions.
Based on actual pressure values for monitored pipeline segments which are stored continuously in the database, the PSIpipelines Stress Monitor analyses permanently pressure trend curves, determines maximum and minimum possible thresholds and calculates the impacts of pressure changes. When the pipeline approaches the end of its lifetime the system generates appropriate messages for further actions that should be initiated by the operator. The system executes calculations in accordance to TÜV AD S1 and S2 technical rules (Analysis for cyclic loading).
Pipeline configuration, wall roughness and pipe friction factor are usually defined as standard values during design stage. Any changes of these values will be compensated by the Real-Time Transient Model tuning methods. Tuning factors which are calculated for each pipeline segment are also monitored against thresholds. The PSIpipelines Wall Roughness Monitor triggers alarms to indicate new scraper runs.
During operation days a pipeline contains different amounts of products, which is caused by temperature and pressure variations. PSIpipelines Inventory Monitor stores the quantities of all pipeline segments in the real-time database and compares each quantity to all threshold levels. The system determines the quantities for each pipeline segment and also for every product in multiproduct
If batches of different products are transported through the same pipeline the operator needs precise information about the moment when the flow path shall be changed. The PSIpipelines Density Monitor identifies the expected density trend and presents all batches and mixing zones fully graphically on the screen. Based on this information the operator decides at which part of the mixing zone the flow path shall be changed in order to avoid any contamination at the delivery point.