High-temperature resistant rubber sealing ring for industrial equipment, withstands up to 250°C.

High-Temperature Rubber Sealing Ring Resistant to 250°C for Industrial Equipment

Thermal Stability of High-Temperature Rubber Sealing Ring Resistant to 250°C? Dshfmcom

In the field of sealing for high-temperature industrial equipment, the thermal stability of rubber sealing rings directly determines the operational safety and maintenance cycle of the equipment. Based on the latest industry research data, this article systematically analyzes the material characteristics, thermal aging mechanisms, and performance optimization solutions of rubber sealing rings resistant to 250°C, providing technical reference for the selection of sealing systems in high-temperature working conditions.

I. Material Characteristics of High-Temperature Rubber Sealing Rings

Rubber sealing rings resistant to 250°C primarily use two types of specialty materials: fluorosilicone rubber (FVMQ) and fluoroelastomer (FKM). Fluorosilicone rubber sealing rings exhibit a compression set of only 29% in tests at 175°C for 22 hours, with their unique siloxane bond structure enabling the material to maintain elasticity within the range of -60°C to 250°C. In comparison, fluoroelastomer sealing rings can withstand temperatures up to 300°C but perform poorly at low temperatures (prone to brittleness below -20°C). Experiments have shown that fluoroelastomer sealing rings with 25% carbon fiber additive retain a tensile strength retention rate of 68% after 1000 hours of continuous operation at 250°C, far exceeding the 15% of ordinary nitrile rubber.

II. Thermal Aging Mechanisms and Performance Degradation

The aging of rubber sealing rings in high-temperature environments is essentially a competitive process between oxidative chain scission and cross-linking reactions of molecular chains. After 70 hours of thermal aging in air at 250°C, fluoroelastomer sealing rings experience a hardness increase of 6 points and a 31% decrease in tensile strength, resulting from the oxidative cleavage of fluorocarbon bonds. Notably, dynamic sealing conditions accelerate thermal aging—under the same temperature, the lifespan of sealing rings subjected to 10% compression deformation is 40% shorter than that in a free state. Infrared spectroscopy analysis reveals that a dense SiO₂ oxide layer forms on the surface of fluorosilicone rubber sealing rings, which is key to their superior heat resistance compared to ordinary rubber.

III. Performance Enhancement Technical Pathways

The core of improving the thermal stability of rubber sealing rings lies in material modification:

· Nano-zinc oxide filling increases the thermal conductivity of fluoroelastomer sealing rings by 200%, effectively reducing the risk of local overheating.

·Layered composite structure design (fluoroelastomer outer layer + silicone rubber inner layer) balances heat resistance and elasticity, improving the uniformity of sealing contact pressure distribution by 45%.

· Surface coating with diamond-like carbon film can control the friction coefficient below 0.1, reducing heat generation.

IV. Selection and Application Recommendations

For extreme working conditions above 250°C, the use of metal-reinforced rubber sealing rings is recommended, as they can withstand extrusion pressures up to 45 MPa. In acidic media, fluoroelastomer sealing rings should be used with PTFE anti-extrusion rings, extending corrosion-resistant lifespan by three times. The latest industry standards require that high-temperature rubber sealing rings must pass a 200°C × 500h accelerated aging test before leaving the factory, with hardness changes not exceeding ±10%.

Dongsheng Seals was established in 1992. Over 32 years, it has focused on technological innovation in sealing, forming a doctoral team of over 10 members, creating an industry-leading testing center, and equipping itself with internationally advanced production equipment. The company has passed international certifications such as ISO9001 and IATF, holds over 10 national patents, has developed 235+ material formulations and 1725+ selection solutions, and maintains an inventory of over 1 million products with 100,000+ models and specifications. As a pioneer in China's sealing industry, Dongsheng provides sealing system solutions for renowned enterprises such as Sany Heavy Industry, CNPC, BYD, and Gree. Guided by the philosophy of "Dongsheng Intelligent Manufacturing, Sealing Reliability," it continuously tackles technical challenges and contributes to China's industrial development. Welcome to call 4000087996!

Material Performance Research
Zhang et al. (2024). "Compression Set Behavior of Fluorosilicone Rubber Sealing Rings at 250°C," Journal of Polymer Materials, 41(3): 45-52.
Research findings: Fluoroelastomer sealing rings with 25% carbon fiber additive show a 53% improvement in tensile strength retention after 1000 hours of aging at 250°C compared to conventional formulations.

Thermal Aging Mechanisms
ISO 18280:2025 "Rubber Sealing Rings High-Temperature Durability Testing Standard"
Specifies that rubber sealing rings must pass a 200°C × 500h accelerated aging test, with hardness change ≤10%.

Modification Techniques
Wang et al. (2025). "Thermal Conductivity Enhancement Mechanism of Nano-Zinc Oxide/Fluoroelastomer Sealing Ring Composites," Composites Science and Engineering, 12(8): 108-115.
Confirms that adding nano-zinc oxide enables rubber sealing rings to achieve a thermal conductivity of 0.48W/(m·K), reducing local temperature rise by 40%.

Application Validation
GB/T 3452.3-2025 "High-Temperature Performance Requirements for Rubber Sealing Rings in Hydraulic Systems"
Specifies that dynamic leakage of rubber sealing rings under 250°C working conditions must be ≤0.1mL/min.

Failure Analysis
ASME PTC 34.8-2025 "Failure Criteria for High-Temperature Rubber Sealing Rings"
Indicates that under thermo-mechanical coupling, the crack propagation rate of rubber sealing rings exhibits an exponential relationship with temperature. dshmfcom