Español
Pусский
Strict and standardized installation, precise control of sealing chamber pressure, and adherence to systematic and regular maintenance are the three pillars that extend the service life of double acting seal, and none of them are indispensable.
1. background
double acting seal form a dual barrier through two independent end faces (first stage+second stage), relying on external isolation fluid (sealing fluid) to achieve sealing, lubrication, and cooling. Its lifespan is not only determined by the material, but also by the adaptability of the working conditions, the stability of the auxiliary system, and the standardization of human operation. In actual failures, over 70% are caused by preventable factors such as installation deviation, flushing interruption, or pressure imbalance.
double acting seal form a dual barrier through two independent end faces (first stage+second stage), relying on external isolation fluid (sealing fluid) to achieve sealing, lubrication, and cooling. Its lifespan is not only determined by the material, but also by the adaptability of the working conditions, the stability of the auxiliary system, and the standardization of human operation. In actual failures, over 70% are caused by preventable factors such as installation deviation, flushing interruption, or pressure imbalance.
2. Key usage points of double acting seal (organized by operational stages)
a. Zero tolerance for errors is required during the installation phase
Radial runout of pump shaft ≤ 0.05mm, axial displacement ≤ 0.1mm, perpendicularity between flange and axis ≤ 0.02mm;
All shoulder chamfers and sharp corners should be rounded, and O-rings should be lubricated with soap solution before assembly;
Clearly distinguish the direction of the moving ring/stationary ring, and the snap ring must be installed in the corresponding limit groove of the sealing chamber.
Radial runout of pump shaft ≤ 0.05mm, axial displacement ≤ 0.1mm, perpendicularity between flange and axis ≤ 0.02mm;
All shoulder chamfers and sharp corners should be rounded, and O-rings should be lubricated with soap solution before assembly;
Clearly distinguish the direction of the moving ring/stationary ring, and the snap ring must be installed in the corresponding limit groove of the sealing chamber.
b. Pressure and fluid management during operation are the core
The pressure of the isolation fluid needs to be consistently higher than the sealed medium by 0.05-0.10 MPa (such as GD type balance tank system). If it is too high, it will cause backflow, and if it is too low, it will lose its barrier effect;
The flushing liquid must be continuously circulated: using a built-in pump efficiency ring or thermosiphon design to ensure uninterrupted cooling and lubrication;
Do not start without liquid! The lack of liquid in the sealed chamber and dry grinding can instantly cause thermal cracking of the end face.
The pressure of the isolation fluid needs to be consistently higher than the sealed medium by 0.05-0.10 MPa (such as GD type balance tank system). If it is too high, it will cause backflow, and if it is too low, it will lose its barrier effect;
The flushing liquid must be continuously circulated: using a built-in pump efficiency ring or thermosiphon design to ensure uninterrupted cooling and lubrication;
Do not start without liquid! The lack of liquid in the sealed chamber and dry grinding can instantly cause thermal cracking of the end face.
c. Daily maintenance requires structured execution
Maintenance type, operation content, frequency/triggering conditions
Visual inspection for leakage traces, flushing fluid flow status, and loose shaft sleeves/covers must be checked every time the machine is stopped
Clean, lubricate, and clean the crystallization of the cavity, clean the filter screen, and apply lubricating grease (to avoid contaminating the end face) to the mating area of the moving ring shaft once a week
Dynamically monitor abnormal noise (spring breakage/jamming), measure sudden increase in leakage, and monitor in real-time during operation
Component replacement: O-rings should be replaced periodically (to prevent hardening failure), and springs should be replaced after elasticity testing according to operating conditions (usually 6-12 months)
Additional explanation: The balance tank auxiliary system has an automatic fluid replenishment function. When the piston benchmark rises to 2/3 of the height, manual fluid replenishment and exhaust are required in a non pressure state; Unused seals must be stored in a dry and dust-free environment to prevent rubber components from aging.
Maintenance type, operation content, frequency/triggering conditions
Visual inspection for leakage traces, flushing fluid flow status, and loose shaft sleeves/covers must be checked every time the machine is stopped
Clean, lubricate, and clean the crystallization of the cavity, clean the filter screen, and apply lubricating grease (to avoid contaminating the end face) to the mating area of the moving ring shaft once a week
Dynamically monitor abnormal noise (spring breakage/jamming), measure sudden increase in leakage, and monitor in real-time during operation
Component replacement: O-rings should be replaced periodically (to prevent hardening failure), and springs should be replaced after elasticity testing according to operating conditions (usually 6-12 months)
Additional explanation: The balance tank auxiliary system has an automatic fluid replenishment function. When the piston benchmark rises to 2/3 of the height, manual fluid replenishment and exhaust are required in a non pressure state; Unused seals must be stored in a dry and dust-free environment to prevent rubber components from aging.
3. Conclusion of how to use double acting seal
The essence of extending lifespan is to minimize human error: installation strictly adheres to tolerances, operation closely monitors pressure and flow, and maintenance is implemented every time the machine stops. Special attention should be paid -90% of early failures occur within the first 3 months of operation, mainly due to residual installation stress or insufficient exhaust of flushing systems. It is recommended to perform three short-term start stop operations within 24 hours after the first operation, observe leaks and temperature changes, and confirm system stability.
The essence of extending lifespan is to minimize human error: installation strictly adheres to tolerances, operation closely monitors pressure and flow, and maintenance is implemented every time the machine stops. Special attention should be paid -90% of early failures occur within the first 3 months of operation, mainly due to residual installation stress or insufficient exhaust of flushing systems. It is recommended to perform three short-term start stop operations within 24 hours after the first operation, observe leaks and temperature changes, and confirm system stability.
