There are three common sealing forms for mud pumps: packing seal, auxiliary impeller seal, and mechanical seal.
1. Filler sealing is mainly used in horizontal mud pumps. It is a common type of seal that continuously injects a certain amount of pressure water into the packing through the injection of shaft seal water to prevent leakage of the pump slurry. For multi-stage series pumps that are not suitable for using impeller shaft seals, packing shaft seals are used. The packing shaft seal has a simple structure, convenient maintenance, and low price.
2. Seal with impeller, corresponding to pump type: horizontal mud pump. It is achieved by applying a reverse centrifugal force to the impeller to prevent the leakage of the slurry. When the positive pressure value at the pump inlet is not greater than 10% of the pump outlet pressure value, the stage pump of a single-stage pump or a multi-stage series pump can use a secondary impeller shaft seal. The secondary impeller shaft seal has the advantages of not requiring shaft seal water, not diluting the slurry, and good sealing effect. Therefore, when dilution is not allowed in the slurry, this type of sealing can be considered.
3. Mechanical seals are mainly used in submersible mud pumps. It is generally used in situations where sealing requirements are relatively high. Especially in some chemical and food industries, not only is sealing required, but it is mainly not allowed to add additional ingredients into the pump body. The disadvantages are high cost and difficult maintenance.