How to ensure that adapters installed on the high-temperature box wall do not expand and deform after being heated?
Adapters (i.e., feedthrough flanges) installed on the walls of high-temperature chambers, in order to avoid harmful expansion or mechanical deformation after heating and to ensure their internal alignment accuracy and sealing performance, typically need to be addressed through three core physical and engineering dimensions: material thermophysical properties, structural stress relief, and thermal isolation design:
1. Ultra-low Thermal Expansion and High Thermal Stability (CTE Matching) of Key Materials
- Application of Special Ceramics: The internal positioning components (e.g., alignment sleeves) of high-precision fiber optic adapters are usually made of special engineering ceramics such as Zirconia ( ext{ZrO}_2). These ceramics have extremely high melting points and very low coefficients of thermal expansion. Even in high-temperature environments of several hundred degrees Celsius, their radial and axial dimensional changes are negligible, ensuring micron-level accuracy for fiber alignment.
- High-Temperature Metal Base: The external metal casing and flange of the adapter are typically made of metal materials with small expansion coefficients and stable properties, such as 316L stainless steel, or special alloys with specific expansion coefficients matched to the chamber wall material.
2. Thermal Stress Relief and Decoupling in Structure (Mechanical Decoupling)
- On the walls of high-temperature chambers, the chamber wall itself (usually large and thick) generates immense internal and surface stresses when expanding due to heat. If the adapter is rigidly connected to the chamber, the deformation stress from the chamber wall will be directly transmitted to the adapter.
- Industrial-grade high-temperature flanges achieve thermal stress decoupling through stepped mechanical seals, non-rigid positioning slots, or special metal sealing rings (such as oxygen-free copper or stainless steel metal rings). By introducing a small elastic deformation margin, they absorb the tangential shear forces caused by the mismatch in the coefficient of thermal expansion (CTE) between the chamber and the adapter materials, preventing warping of the flange body.
3. Thermal Conduction Barrier
- By using high-temperature resistant gaskets with low thermal conductivity (such as mica, high-temperature ceramic sealing sheets, etc.) at the installation contact surface, rapid heat transfer from the inside of the high-temperature chamber to the external adapter connection end is limited. This allows for a smooth temperature gradient transition for the adapter, reducing thermal shock and transient thermal deformation caused by sudden temperature changes.
OFSCN® High-Temperature Flange and Adapter Technical Solutions
In practical applications of fiber optic sensing and fiber optic communication penetration through chamber walls, OFSCN® has designed specialized high-precision high-temperature resistant connectors and adapters:
1. OFSCN® 300℃ High Temperature Resistant Fiber Optic Adapter
- Technical Advantages: This product is designed for extreme thermal environments of 300°C. The core alignment components are made of ultra-high thermal stability materials, which effectively prevent physical deformation in high-temperature environments and ensure stable alignment of high-precision fiber optic interfaces (such as FC/APC, FC/PC, etc.) at high temperatures.
- Product Link: OFSCN® High Temperature Resistant Fiber Optic Adapter
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2. OFSCN® High-Temperature Vacuum Fiber Optic Flange (CF / KF Series)
- Technical Advantages: If the installation environment involves not only high temperatures (e.g., 250°C) but also high sealing or high vacuum requirements (vacuum level up to 1\times10^{-5} Pa to 1\times10^{-7} Pa), this series of flanges uses ultra-high vacuum all-metal and precision melt-sealed structures. This physically eliminates leakage or failure caused by expansion and deformation generated by high temperatures.
- Product Link: OFSCN® High-Temperature Fiber Optic Connectors/Flanges/Splitters