Contact‑free sealing for continuous operation
The hydrodynamic shaft seal operates without mechanical contact and without wearing parts. As a result, it is maintenance‑free and ideally suited for continuous industrial operation.
Using impeller back blades in combination with a downstream auxiliary impeller, the shaft seal is fully relieved hydrodynamically from both pump pressure and inlet pressure. This design keeps the pumped medium reliably away from the shaft gland.
Sealing principle during pump operation
When the pump is running, a liquid ring forms inside the auxiliary impeller. This liquid ring separates the internal pump chamber from the atmosphere, ensuring leakage‑free operation.
The hydrodynamic shaft seal therefore reaches its full sealing performance only during pump operation, when the hydrodynamic forces are active.
Reliable sealing when the pump is stopped
After the pump is switched off, a stationary sealing system takes over the task of sealing the shaft gland from the outside.
Depending on application requirements, the following options are available:
- Simple packing gland
- Pneumatic sealing system
- Mechanically controlled ring valve, available in various designs
This combination ensures safe sealing both during operation and at standstill.
Suitable media and applications
With only a few exceptions, the hydrodynamic shaft seal is suitable for pure liquids as well as solids‑containing media. Typical application areas include:
- Chemical industry
- Process and materials‑based industries
- Environmental and wastewater technology
The design supports reliable operation even under demanding process conditions.
Key benefits at a glance
- Contact‑free, wear‑free sealing principle
- No maintenance required
- Ideal for continuous operation
- Effective separation of pump chamber and atmosphere
- Flexible sealing solutions for standstill operation
- Suitable for a wide range of industrial media
