Why do many of the stainless steel impellers of the ATACH Industrial Water Pump Factory in China have three holes?

Some of the regular customers who received pumps from ATACH Pump Company found that many of the stainless steel pumps had three holes on their impellers. 

So, what is the significance of these holes? 

Regarding the fact that the stainless steel impeller of the Chinese ATACH Industrial Water Pump Factory has three holes (usually three) on it is a common design. 

The main purpose is to balance the axial force and improve the self-priming performance.

In multi-stage centrifugal pumps or certain single-stage high-performance pumps, balance holes are usually opened on the rear cover plate of the impeller. 

The functions of these small holes are:

• ‌Balancing axial force‌: When the liquid is ejected by the impeller, a pressure difference is created between the front and rear of the impeller, resulting in an axial thrust pointing towards the inlet. 

The balance holes allow a small amount of high-pressure liquid to flow back from the rear side of the impeller to the front side, thereby reducing the axial force and lowering the load on the bearings, extending the service life of the pump.

• ‌Auxiliary exhaust and water intake‌: Before the pump is started for the first time, these small holes help to expel air and allow the liquid to enter, providing some assistance in improving the self-priming ability. 

Therefore, the three holes on the impeller are standard engineering practices in the industry, used to enhance the operational stability and reliability of the pump. 

They are not a unique design of ATACH, but conform to the internationally recognized manufacturing standards for water pumps.