What Do We Need To Know About The Sealing Of Slurry Pumps

Nov 22, 2025

With the expansion of the application scope of slurry pumps, the properties of the medium conveyed by slurry pumps are becoming increasingly complex, and there are more and more toxic and corrosive working conditions. Therefore, the sealing problem of slurry pumps is more important. Once the seal fails, leakage will directly cause environmental pollution or threaten human life safety. To solve the sealing problem of slurry pump, it is necessary to have a certain understanding of its sealing form. According to different working conditions of users. Because each of the three sealing forms has its own advantages and disadvantages, namely packing seal, mechanical seal, and secondary impeller seal.

 

 

Firstly, the commonly used sealing form for slurry pumps is packing sealing, where the added packing is in full contact with the shaft to prevent the passage of the conveying medium, thus achieving the sealing purpose. This sealing form may cause corrosion to the packing when transporting corrosive ceramic slurry pump materials, so the disadvantage of this sealing form is that it cannot transport toxic and corrosive liquids.
Secondly, mechanical seals achieve sealing by tightly contacting the moving and stationary rings along the axial direction with springs. Mechanical seals are reliable and almost leak free, but attention should be paid to protecting the friction surface during installation to avoid wear. This seal is mainly suitable for transporting flammable, explosive, high-temperature, high-pressure, and highly corrosive liquids, making up for the shortcomings of packing seals.

The secondary impeller seal is used to prevent liquid leakage through the reverse centrifugal force acting on the impeller. The secondary impeller shaft seal does not require shaft seal water and does not dilute the slurry. This type of seal can be prioritized when the slurry is not allowed to be diluted.

 

In addition, there are other sealing forms such as floating ring sealing, adding small pumps, and adding back blades to the impeller. These sealing forms seal the gap between the shaft and the pump body to prevent liquid leakage from the pump and air from entering the pump.
With the continuous improvement of slurry pump technology, multiple sealing forms have gradually replaced single sealing forms, which can not only make up for the shortcomings of single sealing forms, but also improve the service life and expand the application range of slurry pumps. Combination sealing will also be favored by more and more people in the future.
The selection of sealing form for slurry pump depends on the specific situation of the customer.