If the pump is fitted with oil drain port, firstly fill oil in the pump case.

有泄油口的泵，要向泵壳体中灌满油。

youdao

Oil mist catcher condensate filter and automatic drain pump are set. Oil removed by steam during frying can be recycled to reduce oil consumption and pollution to environment.

设有油雾捕捉冷凝过滤器和自动排水泵，油炸过程中水蒸气带走的油脂可回收，既降低油脂损耗，又减少了对环境的污染。

youdao

There are some systems that actually will take a circle and drop it just below the surface of the water and have the oil kind of flow into it, almost like a drain, recover it and pump it out.

WHITEHOUSE: Daily Press Briefing