... (1), cover (2), impeller (3), axis (4), sealing ring (5) , sleeve (8) and suspension bearing parts (12) ... impeller before and after are equipped with sealing ring and the rear cover plate of the impeller ... lead to the indoor pressure water pump packing ring seal. Without the pump impeller balance holes, ... the cavity part of the protection sleeve and O-ring fitted between the shaft, along with the surface ...