1. In order to prevent blockage, sewage pump is mainly designed with large flow passage, which naturally leads to relatively low efficiency, so the lift is generally not high.
2. In order to prevent winding, the impeller design of the sewage pump is simpler than that of the fresh water pump. There is no retaining ring, but there is a serrated piece, which can crush cloth and other debris and pump it out.
3. In order to prevent abrasion and corrosion, sewage pumps generally adopt mechanical seals with goodabrasion resistance and strong corrosion resistance and O-rings as seals of water pumps.