How to position the first stage impeller of horizontal multistage pump

Before we talk about this problem, let's understand the assembly of the multi-stage pump. First, themulti-stage pump is assembled stage by stage. During the impeller installation, need to set the key at the position of the key groove, and then install the impeller and other parts. When positioning, need to push the impeller hub onto the shaft sleeve or retaining sleeve completely. After the whole multistage pump is assembled, adjust the impeller clearance according to the clearance between the balance plate and the balance ring. Because the old D-type pump allows axial run-out. When the gap between the balance disk and the balance ring reaches the requirements of the drawing, the axial displacement can be stopped. So the first stage impeller of the multistage pump is so positioned. In fact, the simplest way is to see the pump assembly drawing or structural drawing.

Through the above drawing, it can be clearly known that the assembly of multi-stage pump needs to stack up one stage by one stage. When reaches the required stages, we can start to install the suction casing and discharge casing.

In a word, the last step is to adjust the clearance between the balance disk and the balance ring after the superposition and assembly of each stage.

The following points need to be noted:

1. After the pump is assembled, make sure to adjust the clearance of the balance plate as required on the drawing.

2. It is allowed to reserve the gap between the balance plate and the balance ring if the tail cover is not assembled at first. (this is more convenient for pump installation)