Abstract: The working performance of the sieve bend used for draining off medium solids from clean coal used at Gengyang Coal Washery is assessed in a scientific manner based on the industrial test data and by following the relevant standards and specified methods.Result of study shows that the sieve bend works with a remarkable medium draining,desliming and dewatering performance as evidenced by the facts that: the magnetics removal rate for the ＜ 2 mm size coal reaches 96.81%; the dewatering rate for the 0-70 mm whole size range is 95.47% while the rate of correctly placed material of the ＜ 0.25 mm finer size is as high as 95.77%; and its capacity in retaining and recovery of the 1-0.25 mm coarser size is not so high as expected,and 62.29% of the coarser size is seen to be reported to the bend’s dense medium underflow.