Linde Polymer Tec Co.,Ltd. is one of the most experienced manufacturers and suppliers of marine propeller shaft sealing rings in China, also supports customized service. Please feel free to buy high quality marine propeller shaft sealing rings for sale here from our factory.
Products Description
Marine propeller shaft sealing rings are key components between the propeller shaft and the stern tube. Their main function is to prevent seawater from penetrating the hull.
advantages
Excellent Oil Resistance
Marine propeller shaft sealing rings are made of nitrile rubber (NBR), which has a strong tolerance to ship lubricating oil, fuel, and hydraulic oil, and the volume expansion rate after long-term immersion is less than 5%.
Wide Temperature Range Adaptability
The standard model can maintain elasticity in the range of -30℃ to +100℃, and the special formula can be extended to -40℃~+120℃, adapting to environmental changes from cold polar regions to tropical waters.
Dynamic Sealing Ability
Under high-speed rotation of the propeller shaft (maximum 15m/s linear speed) and axial vibration conditions, it can still maintain stable sealing contact pressure.
Economical and Efficient
Compared with complex mechanical seals, O-rings have a simple structure, quick installation, and a unit cost reduction of about 70%.
Functions and Importance
1. Basic sealing function
Marine propeller shaft sealing rings are the first line of defense for the propeller shaft sealing system and undertake more than 80% of the static sealing tasks. When the propeller is stationary, it relies on the elasticity of rubber to fit the metal surface tightly to form a physical barrier.
2. Dynamic compensation function
When the ship is sailing, the vibration and eccentric movement of the propeller shaft may reach ±0.5mm. The flexibility of the O-ring can absorb these displacements to avoid seal failure.
3. System protection value
Prevent corrosion: block the entry of salty seawater and protect the bearing system.
Maintain lubrication: ensure the stability of the lubricating oil cavity pressure and extend the service life of the gearbox.
Environmental compliance: A single ship can reduce 300-500 liters of lubricating oil leakage per year and avoid marine pollution.
Material properties
| Features | Technical Performance | Practical Benefits |
| Acrylonitrile content (18%-50%) | The higher the content, the stronger the oil resistance | The formula can be customized according to the type of ship oil |
| Hardness range (50-90 Shore A) | Multiple specifications available | Precisely match the sealing requirements of different pressure levels |
| Anti-compression permanent deformation | 70℃×24h test deformation rate <15% | Can still maintain good resilience after long-term use |
| Wear resistance | ASTM D5963 test wear loss <50mm³ | Adapt to high-frequency rotation conditions of propeller shaft |
| NBR 70 | ||
| Test Method | Norm | Test Values |
| Hardness | ISO 868 SB | 70 ± 5 IRHD |
| Tensile Strength at break | ISO 37 | 13 N/mm2 |
| Elongation at break | ISO 37 | 300% |
|
Compression Set 70h/23°C 48h/70°C 48h/110°C |
ISO 815 A
|
20% 15% 20% |
|
Heat Ageing 48h/110°C Hardness Change |
ISO 188
|
+8% |
|
Immersion in FAM DIN 51604 2/B 48h/23°C Hardness Change Volume Change |
ISO 1817
|
-16% +34% |
|
Immersion in Diesel, 48h/23°C Hardness Change Volume Change |
ISO 1817
|
-1% +2% |
|
Immersion in Biodiesel DIN 51606 48h/23°C Hardness Change Volume Change |
ISO 1817
|
-3% +4% |
Selection and maintenance guide
- Three Elements of Selection
1. Dimensional accuracy: The inner diameter tolerance is controlled within ±0.01mm to ensure the matching degree with the shaft/groove.
2. Working condition matching:
Regular navigation: Select standard hardness 70 Shore A;
High-temperature area: Select a model with high acrylonitrile content (≥34%);
Low-temperature environment: Use a cold flow improved formula.
3. Certification requirements: Naval ships must meet the MIL-P-25732 standard, and civilian ships should comply with the ISO 3601 standard.
- Maintenance Best Practices
Pre-installation treatment: Lubricate the surface with silicone grease to avoid twisting deformation.
Regular inspection: Measure the compression every 6 months. Replace if the deformation exceeds 15%.
Emergency treatment: In case of temporary leakage, tighten the gland bolts symmetrically, with a maximum adjustment of ≤1.5mm.
Why Customers Choose Us
Complete rubber material formulation
Formula of 2000 rubber materials
Proven custom processes
10,000 sets of seal molds, Seal Structure Design
Free seal performance and life testing
US standard, EU standard, and JP standard of various sealing performance and life testing
Stable production, adhere to zero defects
5 billion pieces a year manufacturing capacity
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