Sealing Excellence, Securing Industry

CFKS Multi-Size Metal Rubber Dowty Seal Hydraulic Sealing Bonded Seals

The CFKS Multi-Size Metal Rubber Dowty Seal Kit provides maintenance engineers with a comprehensive, field-ready assortment of high-pressure hydraulic bonded seals. By permanently vulcanizing a trapezoidal elastomeric sealing lip to the inner diameter of a rigid metal outer ring, these composite gaskets deliver an impenetrable, blowout-proof static boundary for hydraulic fittings, pipe joints, and manifold plugs across varying metric and imperial dimensions.

  • Comprehensive Repair Assortment: Systematically organized by standard fluid power sizes to drastically reduce Mean Time To Repair (MTTR) during emergency hydraulic blowouts.

  • Blowout-Proof Architecture: The rigid metal outer casing acts as an unyielding structural back-up ring, completely preventing the rubber lip from extruding under severe pressure spikes.

  • Vibration-Tolerant Sealing: The elastomeric inner ring absorbs the high-frequency mechanical vibrations of mobile equipment and heavy machinery, preventing fittings from weeping over time.

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 (Dowty washer) over a standard annealed copper or aluminum crush washer lies in its pressure-energized composite design. When a hydraulic fitting is torqued down, the trapezoidal rubber inner ring compresses, deforming to fill the microscopic asperities of both the fitting face and the manifold port. As internal hydraulic pressure violently builds—frequently exceeding 10,000 PSI (700 Bar) in heavy equipment—the fluid actively pushes the elastomeric ring outward against the rigid metal shell. The metal shell completely eliminates the clearance gap, serving as a physical barricade that prevents the rubber from blowing out.

In standard industrial settings or enclosed mobile hydraulic applications (such as excavators, loaders, or agricultural tractors), specifying the right material composition is essential for joint longevity. Our multi-size kits utilize high-grade, corrosion-protected Carbon Steel outer rings. This material provides the exceptional compressive yield strength required to anchor heavy hydraulic fittings without buckling.

From a heavy equipment maintenance perspective, utilizing CFKS bonded seals during a hydraulic repair offers a massive engineering advantage: they require significantly lower assembly torque than traditional solid metal crush washers. Because the elastomeric rubber lip achieves the actual fluid seal, technicians do not have to yield (physically crush) solid metal to create a fluid-tight joint. This preserves the internal threads on expensive hydraulic directional control valves, cast-iron manifolds, and pump housings, completely preventing costly thread-stripping during emergency, high-stress repairs in the field.

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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