AIREXPO Shanghai 2025: Aerospace Industry Event Highlights Metal Sealing Challenges

Introduction

The 9th Shanghai International Aerospace Technology and Equipment Exhibition (AIREXPO SHANGHAI 2025), held at the Shanghai New International Expo Center from June 11–13, 2025, is China's premier aerospace industry event. Building on over a decade of growth, AIREXPO SHANGHAI unites major players across civil aviation, commercial aviation, defense, and advanced manufacturing. This event serves as the industry's launchpad for technology exchange, supply chain alignment, and new material discoveries in one of the world's fastest-growing aerospace markets.

In an era defined by the race for lighter, smarter, and more sustainable flight, AIREXPO 2025 stands as a focal point for innovation—and nowhere is this truer than in the science of sealing. Metal sealing systems play an indispensable, often invisible role in driving advances in fuel efficiency, emissions reduction, safety, and reliability. The challenges and opportunities in aerospace sealing technology will be a critical topic of discussion throughout the exhibition and technical sessions.

Event Highlights: Aerospace Megatrends and Sealing Challenges

AIREXPO 2025 brings together the world's top OEMs, airlines, aircraft finance and leasing institutions, and a deep bench of aerospace engineers for a program spanning commercial airframes, aero engines, electrified propulsion, avionics, and smart manufacturing. The concurrent International Aircraft Engineering Summit and Aircraft Intelligent Manufacturing & Materials Innovation Summit will feature keynote discussions and technical sessions on:

• Sustainable aviation and fuel cell/hydrogen propulsion systems
• Next-generation aerospace materials, including advanced alloys and composites
• Ultra-high vacuum manufacturing and contamination control for avionics & space payloads
• Safety and reliability optimization in engines, landing gear, actuation systems, and flight controls
• The latest in maintenance, repair, and overhaul (MRO) for both commercial and military fleets

A recurring challenge in each of these themes: Creating robust, reliable sealing solutions that withstand extreme pressures, temperatures, thermal cycling, and aggressive media over decades of operation and mission-critical reliability requirements.

Keynotes at AIREXPO 2025 are expected to address:

• The rise of hydrogen aviation and need for 100% leak-tight, high-pressure combustion system seals
• Growth in satellite manufacturing requiring ultra-clean, high-vacuum sealing
• Demand for lower lifecycle cost in MRO, dictating long-life, corrosion-resistant seals for hydraulic and engine systems

These trends put pressure on the entire supply chain to deliver sealing solutions that push the boundaries of metallurgy, design, and process control.

Advanced Metal Sealing Solutions for Aerospace Challenges

The aerospace industry's demanding requirements call for sophisticated metal sealing solutions—spanning O-Rings, C-Rings, U-Rings, V-Rings, E-Rings, Comma Rings, and custom hybrid configurations—that can address the harshest demands of modern aerospace platforms. These challenges will be key discussion points at AIREXPO 2025.

Metal O-Ring Seals

Metal O-ring seals represent the gold standard for static and dynamic aerospace applications requiring exceptional leakage control under high pressure and temperature cycles. Critical configurations include:

• Standard O-Rings: Inconel, stainless steel, and other aerospace-grade alloys, for interface sealing in hydraulic actuators and fuel manifolds.
• Spring Energized O-Rings: Integrated Inconel or Hastelloy springs ensure consistent seal recovery (spring back) and ultra-low leakage, critical in oxygen service and cryogenic propulsion systems.
• Balanced & Gas Energized O-Rings: Specially engineered for differential pressure management in turbine engines, satellite payload enclosures, and UHV test rigs.

Metal C-Ring Seals

When flange surface imperfections or misalignments are unavoidable, Sonkit's C-Ring metal seals are the solution. Available in standard, blade-type, and spring-energized configurations, these seals are preeminent in:

• Engine component junctions, where vibration and cyclic thermal stresses demand robust resilience
• Pressure bulkheads and doors, where axial or internal/external pressurization is present

C-Rings are especially valued for their ability to conform to mating hardware and offer repeatable spring-back after thermal cycling, vital in reusable spaceflight and MRO contexts.

Metal U-Ring Seals

Precision and compactness define Sonkit's metal U-Rings. These seals are engineered for:

• High pressure actuators and landing gear systems, where a small cross-section with very low permissible leakage is mandatory
• Extremely tight hardware envelopes

U-Rings are essential where packaging density and long-term reliability converge. The geometry ensures excellent pressure distribution and embedment tolerance.

Metal V-Ring Seals

For dynamic applications—shaft seals, rotary actuators, and combined static/dynamic interfaces—Sonkit's metal V-Ring solutions excel:

• High spring-back and low load tolerance reduce wear in piston/rod sealing
• Suitable for both reciprocating and rotating applications in avionics and flight control actuators

V-Rings enable high-frequency movement under aggressive aerospace lubricants and wide temperature swings.

Metal E-Ring Seals

The aerospace sector's quest for platforms that experience wide mechanical and thermal displacements—think engine casings and missile canisters—requires seals with high deflection tolerance and recovery. Sonkit's E-Rings deliver:

• Exceptional spring-back for large-scale movement or hardware deflection
• Performance across multi-component interfaces subject to environmental variations

Metal Comma Ring Seals

In valves and pumps—ubiquitous in both ground and flight hardware—Sonkit's comma ring metal seals, with optional internal spring energization, offer:

• Sustained leakage control at high cycling frequencies
• Resistance to rapid pressure fluctuations and chemical attack

Advanced Metal Seal Solutions

Sonkit's advanced solutions leverage:

• Special Alloys: Inconel, Hastelloy, MP35N, titanium
• Custom Coatings: Silver, nickel, PTFE for anti-galling, corrosion resistance, and electrical conductivity
• Hybrid Seal Designs: Combining metal seals with organic or inorganic coatings to meet unique OEM specs for outgassing, cleanliness, or extended life

These innovations enable Sonkit to partner with global aerospace OEMs and Tier 1 suppliers targeting:

• Hydrogen/cryogenic propulsion and storage systems
• Ultra-high vacuum (UHV) satellite and payload chambers
• Corrosive or oxidizing environments in airframe and electronic system sealing meeting AS9100 aerospace standards

Application Examples

• Nuclear and Defense Aerospace: Leak-tight critical hardware, reactor feed valves, missile seals
• Hydrogen Systems: Gas-energized and spring-energized seals ensure zero hydrogen leakage even at extreme cycling
• Semiconductor/UHV Technology: Nickel- or silver-coated O-rings for clean vacuum environments
• Civil & Commercial Aviation: Landing gear, flight control, actuators, and fuel system sealing

Frequently Asked Questions

What's the difference between U-Rings and C-Rings in metal sealing?

U-Rings are compact, U-shaped metal seals that provide high sealing performance in tight hardware spaces, ideal for high pressure and low leakage aerospace applications. C-Rings, with their C-shaped cross-section, are more flexible and can compensate for hardware imperfections or misalignments, making them suitable for larger flanged or dynamic assemblies demanding spring-back under thermal and mechanical cycling.

Why are metal O-rings preferred in vacuum systems?

Metal O-rings provide outstanding vacuum performance because they deform to fill microscopic surface irregularities, achieving ultra-low leakage rates. With the right alloy and optional coatings, they resist outgassing and ensure vacuum integrity at cryogenic and high temperatures—crucial in satellite, space payload, and semiconductor manufacturing.

What's a comma ring seal used for?

Comma ring metal seals, often spring-energized, are specialized for valves and pumps experiencing high-pressure, high-frequency cycling. Their unique profile and energization ensure long service life and tight sealing regardless of fluctuating pressures or aggressive media in aircraft and ground systems.

What is a spring-energized seal?

A spring-energized metal seal includes an internal coil spring or gas charge that presses the seal lip against the hardware, sustaining sealing force even under hardware movement or thermal cycling. This ensures consistent leak-tight performance across a range of pressures, temperatures, and installation tolerances.

When to use advanced coating or plating on metal seals?

Advanced coatings (such as silver, nickel, or PTFE) are used when:

• Seals interface with dissimilar metals (to prevent galling or corrosion)
• There's a requirement for electrical conductivity or insulation
• Severe environments demand extra chemical or oxidization resistance

Sonkit customizes coatings and plating to fit the exact needs of aerospace OEMs, from high-purity vacuums to aggressive combustion hardware.

Conclusion

AIREXPO 2025 is set to be a cornerstone event for aerospace advancement in China and globally. From hydrogen aviation and green airport ecosystems to AI-augmented manufacturing, the expo will spotlight the need for reliable, future-proof technology at every level of flight. As the aerospace industry continues to evolve, Sonkit's comprehensive portfolio of high-integrity metal seals, ranging from O-Rings and C-Rings to customized, alloy and surface-engineered solutions, is engineered to answer these emerging challenges. For engineers, procurement officers, and system designers seeking trusted partners in critical sealing, Sonkit stands ready to deliver performance, innovation, and lasting value.