第一次灌满水后能抽上来水，当停机之后必须再灌满水才能把水抽上来的原因是自吸排污泵出口未装单向阀、并且自吸排污泵出口没有垂直向上1米就拐弯的原因所致、因为自吸排污泵如果出口没有装止回阀会导致停机之后管道里面的回水压力太大把自吸泵腔里面的水带回到水池里面去、所以下次启动必须要再灌水才行，另外出口管道没有垂直向上1米在启动泵一瞬间会把泵腔里面的部分水甩出到出口管道里面去从而导致自吸排污泵无法吸上来水。该现象主要还是取决于自吸排污泵本身的自吸性能。
The reason why the water can be pumped up after the first filling is that the outlet of the self-priming sewage pump is not equipped with a one-way valve, and the outlet of the self-priming sewage pump does not turn vertically for 1 meter, because if the outlet of the self-priming sewage pump is not equipped with a check valve, the return water pressure in the pipeline will be too large after the shutdown, and the return water pressure in the self-priming pump cavity will be too high. The water is brought back to the pool, so the next start-up must be refilled with water. In addition, the outlet pipe does not rise vertically for 1 meter. In the instant of starting the pump, part of the water in the pump cavity will be thrown out into the outlet pipe, which will cause the self-priming sewage pump to fail to absorb the incoming water. This phenomenon mainly depends on the self-priming performance of the self-priming sewage pump itself.