Document Type: Research Paper
Babol Noshirvani University of Technology
When a natural gas pipeline ruptures, the adjacent upstream and downstream automatic control valves (ACVs) should close quickly to prevent leakage or explosion. The differential pressure set point (DPS) at each valve location is the main criteria for value setting in ACV action. If the DPS is not properly adjusted, the ACV may mistakenly close or it may not take any action at proper time. In this study, the effect of characteristic parameters such as pipeline operational pressure (POP) and pipeline pressure drop rate (ROD) due to rupture or major leak was experimentally investigated on DPS. 25 different conditions with double set of typical mentioned characteristic parameters were chosen. For each condition, the differential pressure (DP) was measured over 180 s by statistically analyzing the experimental results. Therefore, 25 maximum DP values (DPSs) were obtained. The DPS increases by increase in ROD or decreasing POP parameters. Because of using nitrogen gas instead of natural gas due to safety reasons and the uncertainties, the DPS results can be practically applied by adding a safety factor of 15%. Finally, the diagram of DPS with respect to ROD and DOP versus RTP were provided for different POPs.