Sealing Excellence, Securing Industry

CFKS Hydraulic Cylinder DH Dust Oil Seal 38*46*5/6.5 PU DH Wiper Oil Seal

The CFKS DH Series is a high-performance, double-acting dust seal designed to provide a critical barrier against external contaminants. Molded from premium-grade Polyurethane (PU), this 38*46*5/6.5 mm wiper effectively removes mud, dust, and moisture from the reciprocating rod while simultaneously acting as a secondary seal to contain the residual oil film.

Dual-Lip Functionality: The external lip excludes environmental dirt, while the internal lip retains the lubricating oil film.

High Abrasion Resistance: Specialized PU compound offers superior wear life compared to standard NBR wipers.

Snap-In Installation: Designed for standard 5/6.5 mm stepped grooves for a secure,interference fit.

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 DH Oil Seal   Packing 1 pc per bag

 

The DH (Dust-Hydraulic) wiper operates on a dual-zone engineering principle. Unlike single-lip wipers that only provide external protection, the DH profile features an inner sealing lip that works in tandem with the primary rod seal. This “secondary seal” action traps the microscopic oil film during the rod’s extension and wipes it back into the system during retraction. This prevents “weeping” at the rod head. The outer scraper lip is designed with a high radial preload to ensure constant contact with the rod surface, effectively shearing off even the finest abrasive particles before they can enter the gland and damage the primary pressure seals.

In construction and industrial environments, wipers are subjected to harsh mechanical impacts and UV exposure. Our DH seals are manufactured from a high-modulus 95 Shore A Polyurethane (PU). This material is chosen for its exceptional tensile strength and “memory,” allowing the wiper lip to maintain its sharp scraping edge over millions of cycles. Compared to Nitrile (NBR), our PU compound offers 3 to 5 times the abrasion resistance and remains flexible in temperatures ranging from -35°C to +100°C, preventing the brittle cracking that leads to catastrophic cylinder contamination.

From a maintenance standpoint, the 38*46*5/6.5 DH wiper is the first line of defense for the entire hydraulic system. A worn wiper allows abrasive grit to enter the cylinder, which acts like sandpaper on the chrome rod and primary seals. The 5/6.5mm stepped profile is engineered for a “snap-in” fit into open grooves, requiring no special tools for replacement. Because the PU material is resistant to “compression set,” it maintains a tight seal against the housing bore, preventing moisture from seeping behind the seal and causing corrosion in the gland area.

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.

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