Abstract: In many cases, the maximum length of pipelines calculation is based on the condition of the same flux, but considering the influence of the pipe head loss, the flux is not equal. Therefore, the results of the calculation of the maximum length of pipelines with multiple outlets are compared with the two cases of equal flux and unequal flux. Meanwhile, under the condition of double pipe arrangement a row, the effect of different water supply way on the maximum length of drip pipeline was analyzed. The results show that using the arrangement of double pipes to supply water for a line crop from two sides can significantly increase the maximum length of the pipelines, reduce the amount of branch pipe and save investment. The results of this research can be used to design of micro-irrigation system.

Key words: maximum length, head loss, drip tape