Failure behavior of pressure compensating emitter under different operation pressures in drip irrigation systems

Pressure compensating emitters (PCE) can maintain a consistent irrigation flow rate under varying pressures through its internal compensation diaphragm and effectively improve the irrigation uniformity of drip irrigation systems. However, the PCE function is prone to failure, particularly when using marginal water, which can cause various technical and economic problems. To date, little is known about the failure behavior of PCE. This study investigated the effects of three pressures (0.1Mpa, 0.2Mpa, and 0.3Mpa) on the failure behavior of PCE. Then the dynamic changes in clogging substances and diaphragm performances in PCE channel were monitored. The results showed that as the system operation increased, the performance of PCE gradually decreased. The CU>80% running time was 172.8–634.9 h, and the flow index >0.2 running time was 120.1–768.1 h. The failure of PCE is primarily caused by two factors: clogging of the PCE flow channel and deterioration of the diaphragm mechanical performances. The flow rate of PCE increased by 22.6% on average at 0.3Mpa compared to 0.1Mpa, and clogging substances in the PCE flow channel decreased by 19.8%. Meanwhile, increasing the operating pressure improved the mechanical performance of the diaphragm. Under the operating pressure of 0.3Mpa, the diaphragm’s elasticity and hardness increased by 14.6% and 12.8%, respectively. Therefore, this study is of significance in popularizing PCE drip irrigation technology and marginal water utilization.