Countermeasure of water hammer in pressure-reducing pipeline system using surge relief valve

摘要

We conducted a field test on a pressure-reducing pipeline system equipped with a new type of automatic control valves for field irrigation, and verified its pressure reducing function, reproducing the results of measurement by simulation using a mathematical model. The simulation of generating status of water hammering pressure brought about by the operation of a diversion device at the end of pipeline revealed that the rapid closeout of the terminal valve propagated pressure wave upstream through the automatic control valves. As a countermeasure for restraining the water hammering pressure, the installation of a surge relief valve was studied. As a result, it was found effective to install the surge relief valve at the end of the pipeline for the downstream side of a pressure-reducing valve(automatic control valve), and it was found effective to additionally install it at the upstream side of a pressure-reducing valve. It was also found that the size of the surge relief valve requires about the same level as the main pipe in terms of diameter.