Nozzle sealing rings feature diversified properties for different application scenarios. Centered on reliable sealing performance, they adopt optimized materials and structural designs to fit specific working conditions. The characteristics are explained from three dimensions: material properties, structural features and application performance.

1. Material Properties: High Temperature Resistance & Corrosion Resistance as Core Requirements

High-temperature toleranceFor high-temperature applications such as iron & steel metallurgy and continuous casting, sealing rings must withstand sustained temperatures above 1000°C. For instance, zirconia-containing aluminum silicate fiber sealing rings are formulated with zirconia oxide (ZrO₂ content: 10%–18%), raising the temperature resistance limit to over 1400°C while maintaining low thermal conductivity (0.03–0.06 W/(m·K)) to reduce heat transfer.

Chemical stabilityMaterials for sealing rings deployed in acidic and alkaline environments must resist chemical attack. EPDM (Ethylene Propylene Diene Monomer) sealing rings used in chemical equipment can resist acids, alkalis, salts and organic solvents. Their continuous service temperature ranges from -40°C to 150°C, and they resist cracking and hardening.

Wear resistance and elasticityFor heavy-load scenarios including hydraulic and mechanical systems, sealing rings need both wear resistance and elasticity. NBR (Nitrile Butadiene Rubber) sealing rings, with acrylonitrile components, deliver outstanding wear resistance and withstand high-pressure friction. However, they have poor cold resistance and tend to harden at low temperatures, making them suitable for ambient-temperature environments.

2. Structural Features: Special-Shaped Design & Self-Compensation Improve Sealing Effect

Special-shaped cross-section designConventional O-rings achieve sealing via pre-compression, while special-shaped sealing rings (square, D-shaped, X-shaped) increase contact area to boost sealing force. Square sealing rings are widely used in water bottles and tumblers to compensate gaps between caps and bottle necks and prevent liquid leakage. Continuous casting nozzle sealing rings adopt truncated cone profiles with round holes to realize uniform compression and slight thermal expansion, avoiding secondary contamination caused by air contact with molten steel.

Self-compensating and easy-to-disassemble structureFor valve applications, sealing performance and convenient maintenance are equally important. Valves for water supply projects use double-plate truss valve plates paired with premium EPDM seals. Sealing tightness is self-compensated by eccentric displacement — the seal gets tighter as the valve closes. The sealing ring is fastened with screws for on-site adjustment or replacement, lowering long-term operating costs.

Multi-layer composite structureSealing rings for reverse osmosis membrane housings combine EPDM and engineering thermoplastics. They meet sealing requirements under high operating pressure from 150 psi to 1200 psi. Threaded side-hole designs simplify maintenance and reduce manifold costs.

3. Application Performance: Scenario-Oriented Optimization

Iron & Steel Metallurgy: High-temperature anti-contaminationLong nozzle sealing rings block air ingress at the joint of ladle nozzles to prevent molten steel oxidation. Zirconia-containing aluminum silicate fiber sealing rings fill gaps through slight thermal expansion. Their high-temperature stability prevents falling off during steel pouring and greatly improves slab quality.

Chemical & Food Industry: Corrosion resistance and food safetyChemical sealing rings resist acid and alkali erosion, while food-grade seals need certifications such as FDA and LFGB. Silicone sealing rings, non-toxic and odorless, withstand temperatures from -60°C to 250°C. They are widely used in steam valves for electric kettles and infusion devices.

Water Pumps & Valves: High pressure resistance and long service lifePump sealing rings endure high pressure and frequent opening-closing cycles. V-type sealing rings compensate for dimensional tolerances axially to stop hydraulic oil leakage. Valve seals made of carbon fiber impregnated PTFE have a low friction coefficient and can serve up to ten years under frequent operation.

Drinkware & Home Appliances: Balance of sealing and usabilitySeals for cups and tumblers balance sealing performance and user-friendliness. Vacuum flasks combine primary silicone seals and auxiliary special-shaped seals; pre-compression design ensures reliable sealing under normal pressure. Sealing rings for washing machine drain pipes adopt magnetic or adjustable structures to fit different pipe sizes and block odor backflow.