Working Principle
During pump operation, the expeller rotates at high speed to generate counter-acting centrifugal pressure (air or fluid), forcibly throwing high-pressure slurry or sand-laden fluid—which would otherwise migrate toward the shaft seal—back into the pump chamber.
Simultaneously, the pressure-reducing cover forms a sealed pressure-relief chamber, significantly lowering the pressure of the pumped medium acting on the stuffing box and mechanical seal.
Result:
Virtually zero leakage during operation; particles are prevented from entering the sealing area; and the shaft seal is protected from overheating, slurry spraying, and excessive pressure buildup. Relies on auxiliary packing seals during shutdown to eliminate static leakage, making it suitable for 24-hour continuous industrial operations.
Core Product Features
Auxiliary Impeller Features
1. Dynamic pressure reduction and self-sealing
Does not rely on hard-friction sealing; uses fluid pressure to block slurry. Resistant to silt and particles; seal burnout is unlikely.
2. Protects shaft sleeves and mechanical seals
Blocks over 90% of fine sand particles from entering the sealing interface, significantly reducing shaft sleeve wear, mechanical seal failure, and packing burnout.
3. Stable operation and vibration resistance
Cast as a single unit with high dynamic balance precision; operates at high speeds without wobbling or uneven wear.
4. Suitable for harsh operating conditions
High-chrome alloy offers high hardness and erosion resistance; rubber materials provide corrosion resistance against mildly acidic or alkaline slurries.
Pressure-Reducing Cover Features
1. Precise pressure relief and balancing
Stabilizes pressure in the seal chamber and prevents high-pressure slurry from directly impacting the shaft seal, fundamentally solving common issues like slurry spraying, water seepage, and solids leakage.
2. Precise positioning and excellent fit
Strict adherence to original factory mold dimensions ensures uniform auxiliary impeller clearance and stable sealing performance; no grinding required during installation.
3. Wear and deformation resistance
Thick-walled cast structure offers high pressure tolerance and resistance to deformation and erosion-induced perforation, ensuring a long service life.
4. Reduced maintenance frequency
When used with the auxiliary impeller, there is little need for frequent water seal adjustments or packing replacements, drastically lowering downtime and maintenance costs. IV. Overall Core Functions
1. Leakage Prevention: Dynamic sealing ensures zero slurry leakage or water seepage during operation.
2. Pressure Reduction: Relieves high pressure on the shaft seal, protecting the entire sealing system.
3. Sand Exclusion: Blocks particles from entering the seal chamber, protecting the shaft sleeve and mechanical seal.
4. Operational Stability: Eliminates cavitation, pressure buildup, and overheating, ensuring long-term, stable pump operation.
5. Cost Savings: Reduces wear on seals and shaft sleeves, lowering the rate of post-sales failures
