When a joint must survive pressure spikes, thermal swings, and vibration, plain gaskets tend to creep or extrude. The bonded seal series solves this with a smart hybrid: a metal backbone permanently bonded to an elastomeric sealing lip. Under a bolt head, on a threaded shoulder, or at a port plug, tightening alone creates a robust face seal. That’s why mechanical engineering, hydraulic and pneumatic circuits, and the oil and gas sector rely on them for bolted and threaded connections and pipe joints where high-pressure sealing is non‑negotiable.
Construction and materials: small part, big engineering
Two‑layer design: a metallic outer ring—typically carbon steel or stainless steel—bonded to an inner elastomeric ring, most commonly NBR. Heat and pressure bonding locks the elastomer in place, resisting blowout and extrusion.
Centering options: self‑centering variants add an inner lip to locate the washer concentrically during assembly; non‑self‑centering types fit broader geometries and custom hardware.
Material choices:
· Metals: zinc‑plated or phosphated carbon steel, stainless 304/316, special alloys on request.
· Elastomers: NBR (general oil resistance), FKM (high‑temperature and chemical resistance).
· Surface finishes like zinc, nickel improve corrosion resistance and assembly feel.
Pressure, temperature, and how they seal
· Sealing principle: clamp load compresses the elastomer between two faces; the metal ring limits lateral flow and reinforces the lip against burst. Compared with plain rubber gaskets, bonded seals carry higher pressure and resist extrusion.
· Pressure capability: standard designs commonly handle mid‑to‑high static pressures in hydraulic service, with enhanced sections pushing higher; the ceiling depends on size, materials, and surface prep and should be validated for your duty cycle.
· Temperature windows (typical): NBR about -40 to 125°C; FKM about -20 to 250°C. Near the upper limit, watch compression set and media compatibility.
· Versus O‑rings: bonded seals need no precision gland; the metal ring itself retains the elastomer, simplifying machining and lowering sensitivity to surface geometry on bolt heads, threaded bosses, and plugs.
Where they shine: applications and industries
· Connection types: bolt/stud face sealing, BSP/NPT/Metric/SAE threaded shoulders, flange auxiliaries, plugs and sensor ports.
· Duty profiles: high‑pressure sealing, thermal cycling, oil/chemical exposure, vibration, or micro‑movement at the joint.
Industries and equipment that benefit:
· Pumps, motors, gearboxes, engines, and lube systems
· Hydraulic and pneumatic systems; construction and agricultural machinery
· Oil and gas production and transfer; chemical plants and metallurgical lines
· Energy sector including wind turbines (yaw/pitch hydraulics)
· Water treatment skids, marine/offshore connections
· Commercial vehicles and passenger cars (chassis hydraulics)
· Industrial machinery and robotic actuators where hydraulic drives are
used
DEDE brand and what you get with us
DEDE has focused on oil seals and O‑rings for over three decades, operating to ISO 9001 and TS16949 and building an integrated R&D–manufacturing–quality system.
Services you can count on:
· Fast shipment of standard parts: a broad catalog with deep inventory to keep urgent lines running.
· End‑to‑end customization: from elastomer selection and washer geometry to coatings, sizing, and validation—dialed to your media, pressure, and temperature.
· Technical enablement: leveraging 30+ years in sealing to optimize your hydraulic/pneumatic stacks, reduce maintenance cost, and lift reliability.
Company highlights:
· In‑house manufacturing; seasoned sealing specialist
· Wide model coverage with ready stock
· Shipments to 80+ countries
· Partnerships with well‑known global brands
· Provincial technology innovation center; “specialized‑refined‑innovative” enterprise; high‑tech enterprise
· Leader in a featured industrial cluster
Selection and installation that pay off
· Materials first: choose elastomer by media and temperature; then match metal ring to corrosion and strength needs—stainless is a safe pick for marine exposure.
· Size and centering: match ID/OD to bolts and shoulder faces; self‑centering types speed assembly and improve concentricity.
· Surfaces and preload: keep faces flat, with surface roughness ideally ≤ Ra 1.6 μm; apply torque per fastener grade and lubrication to avoid over‑crushing the lip.
· Reuse policy: treat as a condition‑based consumable—replace if you see nicks, set, or aging.
· Commissioning: ramp pressure on first build, leak‑check, and consider re‑torque after initial thermal cycles for long‑term stability.
The bonded seal series turns a stubborn problem—face sealing under pressure—into a predictable, repeatable operation. It trims machining effort, shortens assembly time, and adds a safety margin where you need it most: around every critical threaded connection. If your project hinges on high‑pressure integrity, put bonded seals on your shortlist—and when your specs point to non‑standard sizes or challenging media, DEDE is engineering team is ready to move you from guesswork to confidence.
