At chemical production sites, pumps undertake the task of conveying various media, and the reliability of the sealing system is directly related to production safety and efficiency. However, mechanical seal leakage has always been one of the most intractable faults for on-site operation and maintenance personnel. Problems such as re-leakage of newly replaced mechanical seals in a short period of time and massive liquid leakage at the moment of start and stop are frequently encountered. In fact, 80% of seal leakages are not caused by accessory quality problems, but by the combined effect of abnormalities in multiple links.

-Bonve Pumps Cam-type Twin Rotor Pump-

First of all, it is necessary to distinguish leakage scenarios. During the static pressure test of a new mechanical seal, trace leakage is mostly caused by deformation or assembly damage of the rotating and stationary ring auxiliary O-rings, while a large amount of liquid channeling indicates friction pair fitting failure due to end face bumping or impurity embedding. If the leakage remains unchanged after barring operation, it points to the stationary ring or shaft sleeve seal; if the leakage worsens, it is mostly due to rotating ring end face offset.

Continuous slow leakage during normal operation is usually caused by slight wear of the sealing end face, spring jamming or medium crystallization which prevents the rotating ring from floating and fitting. Sudden jet leakage during operation is mostly caused by pump cavitation or severe vibration that breaks the friction pair. The core cause of leakage after long-term shutdown and restart is that medium crystallization adheres to the sealing surface and rubber parts lose elasticity. Intermittent repeated leakage is related to excessive axial run out of the rotor, bearing looseness and equipment alignment deviation.

Standardized troubleshooting must follow the sequence of process conditions → equipment body → auxiliary systems → seal accessories. First, check the process to confirm whether there is cavitation, pressure holding, sudden flow change, whether the medium contains particles or is easy to crystallize, and whether the operating parameters exceed the design range. For rotor pumps conveying high-viscosity media, pump cavitation caused by insufficient inlet pressure is a common inducement for seal damage.

Second, inspect the equipment body, verify the alignment accuracy of the motor and pump body, and check for bearing wear, shaft sleeve corrosion and scratches. Then check the seal auxiliary system to confirm the flushing flow and pressure, cooling system temperature and seal fluid tank status. Finally, troubleshoot seal assembly and quality issues, including whether the compression amount is compliant and whether the accessories are properly selected and matched.

In terms of targeted solutions, for particle wear, it is necessary to clean the pipeline and improve front-end filtration; for medium crystallization, optimize the process temperature and strengthen seal flushing; for excessive axial run out, replace the bearings and correct the alignment.

In daily operation and maintenance, it is prohibited to operate equipment with damage. It is recommended to replace mechanical seals in a complete set after failure, match the seal material according to medium characteristics, conduct regular inspection of auxiliary systems, and implement standardized start-stop operations to reduce seal impact.

Bonve pump always adheres to the philosophy of "Wholeheartedly Making Good Rotor Pumps," committed to providing global customers with customized conveying and mixing solutions. If you have technical inquiries, selection needs, case references, or other cooperation intentions related to Bonve rotor pumps, please feel free to contact us.  

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We look forward to working with you to drive efficiency and innovation in industrial fluid transmission with precision technology.