There are second cutting, third cutting, why three times?
So some pumps are written in the back of XXXX-125A or B, that is, the impeller nominal diameter is 125, A is through a cut, B is the 2 cutting. To reach the applicable conditions, only the calculation is not enough, but also after cutting to test to determine.
There are 2 situations, first, for example, a XXXX-160 type pump head 32, flow 100, motor 15kW, according to the model we need to cut a become head 28, flow rate of 88, this time, in addition to cutting the impeller, the pump or the original pump motor, became 11kW this is, re designed a new model, namely XXXX-160A, but most structural components did not change. In the same way, we want to design a XXXX-160B that makes the head 24 and the flow rate 80, then we just need to cut the impeller again and match the smaller (7.5kW) motor (the motor bracket needs to be redesigned). In general, multiple cutting impellers are designed to expand and enrich the model. Second, the actual use, if you think the flow head is too large, but also can be cut to make it smaller to adapt to practical applications. But the 2 and 3 cuts you ask are the first.
I used to do this job before. After the impeller is cut, the flow and lift will decrease. Sometimes, the same pump will be cut according to the needs of the impeller, so as to meet the actual needs, at this time, with the power of the motor will also be reduced