Sealing Excellence, Securing Industry

CFKS NBR Bonded Seal Kit Stainless Steel High Pressure Dowty Washers for Hydraulic Repair Kit

The CFKS Stainless Steel NBR Bonded Seal Kit provides field technicians and maintenance engineers with a comprehensive assortment of high-pressure Dowty Washers. Essential for emergency fluid power repairs and routine manifold maintenance, these composite gaskets fuse a rigid stainless steel outer ring with a trapezoidal elastomeric inner lip, delivering an impenetrable, blowout-proof boundary for hydraulic fittings and pipe joints across multiple metric and imperial port sizes.

  • Comprehensive Repair Assortment: Drastically reduces Mean Time To Repair (MTTR) by providing exact-fit seals for various BSP, Metric, and SAE hydraulic ports in one organized kit.

  • Extreme Extrusion Resistance: The rigid stainless steel outer casing acts as a structural back-up ring, preventing the rubber lip from blowing out under severe hydraulic pressure spikes.

  • Corrosion-Proof Architecture: Premium stainless steel construction offers total immunity to rust, outlasting standard zinc-plated carbon steel kits in offshore, marine, and harsh industrial environments.

Find your sealing solution with CFKS — contact us for a quote.

Brand Name CFKS OEM  Accpetable
Material NBR FKM Silicone  Features  wear resistance
Dimensions Customized Certificate  ISO9001/TS16949
Type Bonded Seal  Packing 1 pc per bag

 

The mechanical superiority of a bonded seal over a standard metal crush washer lies in its pressure-energized composite design. When a hydraulic fitting or banjo bolt is torqued down, the trapezoidal NBR inner ring compresses to fill the microscopic asperities of both the fitting face and the manifold port. As internal hydraulic pressure builds—often exceeding 10,000 PSI (700 Bar)—the fluid actively pushes the elastomeric ring outward against the rigid stainless steel shell. The metal shell completely eliminates the clearance gap, preventing the rubber from extruding.

The dynamic inner sealing elements across the entire kit are molded from a highly cross-linked, high-density Nitrile Butadiene Rubber (NBR). This optimized NBR matrix is strictly engineered for standard mineral-based hydraulic oils, pneumatic systems, and water-glycol fluids operating in temperatures up to 100°C. It actively resists the chemical degradation and swelling that destroy standard commercial rubbers, ensuring a leak-free static joint for the lifetime of the hydraulic assembly.

From a plant maintenance perspective, replacing standard copper or aluminum crush washers with CFKS bonded seals during a repair offers a massive engineering advantage: they require significantly lower assembly torque. Because the elastomeric NBR lip does the actual fluid sealing, technicians do not have to yield (crush) solid metal to achieve a fluid-tight joint. This preserves the threads on expensive hydraulic valves, directional control blocks, and cast-iron manifolds, preventing costly thread-stripping during emergency repairs.

Frequently Asked Questions (FAQ)

Why does my CFKS oil seal fail prematurely? Common causes and prevention tips2025-06-26T15:44:39+08:00

Premature oil seal failure can result from improper installation, poor shaft finish, incorrect material selection, or excessive pressure. To prevent this, ensure the shaft surface is smooth and within tolerance, use correct tools during installation, and choose seals made from materials compatible with your media and temperature.

How to correctly install a CFKS industrial oil seal to avoid leakage2025-06-26T16:04:32+08:00

Always clean the shaft and bore before installation. Use appropriate seal drivers to avoid deformation. Lubricate the lip before fitting to reduce friction during the first rotation. Ensure the seal is seated evenly and not tilted to avoid leaks.

What to do when your CFKS hydraulic seal is leaking under pressure2025-05-20T16:33:14+08:00

Check if the pressure exceeds the seal’s rated limit. Examine for wear, hardening, or improper installation. Replace the seal if damaged, and consider upgrading to a high-pressure CFKS seal variant. Also, verify that the housing and shaft are properly aligned.

How to choose the right CFKS oil seal for extreme operating environments2025-05-20T16:34:39+08:00

For high temperatures, aggressive chemicals, or abrasive environments, choose CFKS seals made of FKM, PTFE, or high-performance elastomers. Consider using seals with protective dust lips or metal casing. Our team can recommend the best fit for your application.

CFKS Seal Manufacturing Co., Ltd.
https://cfksseals.com/
 Email: cfksnacy@gmail.com  Mobile/WhatsApp/Wechat: (86) 188-3097-5917
Bonded Seal Size List
MIDInner diameter toleranceODOuter Diameter ToleranceApplicable Thread
66.4±0.1212±0.12M6
88.414M8
1010.416M10(G1/8")
1212.418M12
1414.420±0.15M14(G1/4")
1616.422M16
1818.425M18(G3/8")
2020.5±0.1428M20
2222.530M22(G1/2)
2424.532±0.20M24
2727.535M27(G3/4")
3030.538M30
3333.5±0.1742M33(G1)
3636.646M36
3939.650M39
4242.653±0.25M42(G11/4)
4545.656M45
4848.760M48(G11/2)
5252.7±0.2066M52
6060.775M60(G2")

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