The x ring also known as a quad-ring, is a four-lip seal with an X-shaped cross-section. Unlike an O-ring’s round profile, the x ring is geometry creates two lubrication pockets and four contact lines. It can be installed in dedicated, lower-squeeze grooves to reduce friction, yet it is also dimensionally interchangeable with AS568A O-rings, making it a drop-in enhancement in many legacy designs.
What it is and how it seals
· Pressure-energized contact: Pre-compression builds radial and axial contact stress; as system pressure rises, sealing force increases accordingly. This double-acting behavior supports bidirectional sealing in static, reciprocating, and rotary duties.
· Materials and temperature window: Mainstream compounds include NBR and FKM, covering roughly -40°C to +250°C. Media compatibility spans hydraulic oils, water, and gases; choose the compound to match fluids, temperature profile, and duty cycle.
· Groove flexibility: The x ring works in O-ring grooves for rapid adoption, or in dedicated low-squeeze grooves to cut friction and heat generation in dynamic applications.
Why choose an x ring over an O-ring
· Lower friction and breakaway: The twin lubricant reservoirs between sealing lips foster film formation, reducing startup drag and steady-state friction.
· Anti-twist stability: The non-circular section resists rolling and twisting in reciprocating motion, mitigating premature leakage paths common to O-rings under sliding loads.
· Focused sealing: The flash positioned in the recessed zone of the section concentrates contact where it matters, supporting consistent sealing.
· Four contact lines: Compared with two on O-rings, four contact lines distribute stress and improve sealing efficiency at comparable squeeze.
· Pressure robustness: With proper hardware, clearances, and, where appropriate, backup rings, x rings can operate in high-pressure systems up to about 40 MPa while keeping extrusion risk under control.
Groove and sizing guidelines
· Use cases for grooves: Start with existing AS568A O-ring grooves for retrofit programs. For high-duty dynamics, consider purpose-designed x ring grooves with reduced squeeze to manage heat and wear.
· Dimensional tips:
Static bore seals: keep the x ring ID-to-groove-OD mismatch within about 2% to secure pre-compression without overstress.
Rotary shaft seals: size the x ring ID approximately 2–5% larger than the shaft to account for thermal growth, frictional heating, and film stability.
Dynamic preference for thicker sections: thicker cross-sections better tolerate wear, show more favorable compression set, and accommodate larger motion gaps; static interfaces can also succeed with smaller sections.
· System-level checks: Balance peak and continuous temperatures, pressure and pulsation profile, medium, motion type, and cycle life targets. In rotary duties, explicitly model frictional heat and heat rejection paths.
Pressure and performance in practice
· Friction management: Four lips, two reservoirs, and lower squeeze options combine to cut breakaway and sliding friction, aiding efficiency and life.
· Extrusion control: Pair with suitable hardware clearances and, where needed, anti-extrusion rings to keep edges supported at high differential pressure.
· Surface and hardness: Functional finish and durometer matter: typical 70–90 Shore A balances sealing resilience, extrusion resistance, and installability.
· Media and aging: Match NBR/FKM to fluid families and temperature; monitor compression set and plan maintenance in high-cycle equipment.
Applications and audiences
· Pumps and hydraulic systems: Pistons, rods, and shaft interfaces in cylinders and hydraulic power units benefit from low-friction, anti-twist sealing.
· Motors, gearboxes, and engines: Shaft ends, covers, and auxiliary drives where oil retention and stable dynamics are critical.
· Industrial machinery and robotics: Actuators, rotary joints, and reducers in automated cells and robotic arms.
· Construction machinery and energy systems: Load-bearing hydraulics with pressure pulsation and variable cycles.
· Wind power, metallurgy, chemical processing, and water treatment: From static flanges to dynamic shafts across mixed media and temperature profiles.
· Marine, rail, automotive, and heavy trucks: Drivetrain, auxiliary systems,
and fluid handling where interchange with O-rings eases design and service.
DEDE brand, services, and highlights
· Ready-to-ship standard parts: Broad inventory spanning O-rings, oil seals and the x ring in thousands of AS568A sizes for fast response.
· End-to-end customization: Material selection, groove design, prototyping, and testing tailored to your load case, from low-temperature starts to high-pressure dynamics.
· Technical enablement: Over 30 years of field experience to optimize friction, wear, leakage control, and maintenance intervals for better reliability.
Company highlights:
· In-house manufacturing: integrated production and testing for predictable delivery.
· Wide model coverage with stock depth: shortened lead times for spares and new builds.
· Global footprint: serving customers in 80+ countries across diversified industries.
· Accreditations and platforms: provincial technology innovation center, specialized-and-innovative enterprise, high-tech enterprise, and active participation in regional industrial clusters.
If your target is to cut friction and breakaway, prevent twist-induced
failures, and stay interchangeable with AS568A O-ring hardware, the x ring
series is a pragmatic upgrade path. Share your temperature, pressure, medium,
motion, and gap details, and DEDE will propose a fit-for-purpose selection and
samples on a short timeline.
