Advanced Multi-Layer Bellows for Ultra-High-Voltage Power Applications

Constructed from high-grade austenitic stainless steel strips (typically 304 or 316L), the bellows are produced using precision pulsed TIG (Tungsten Inert Gas) welding, ensuring superior weld integrity and fatigue resistance. The multi-layer thin-wall structure, typically consisting of 3 to 5 layers with individual thicknesses ranging from 0.15 to 0.3mm, is meticulously engineered to balance flexibility and strength. Through advanced waveform optimization, the bellows achieve exceptional mechanical properties, including axial stiffness of 50-200 N/mm and radial stiffness of 300-800 N/mm, making them ideal for high-pressure environments.

Designed to operate in SF6 insulating gas at a rated pressure of 0.6MPa, these bellows exhibit outstanding stability across a wide temperature range (-40°C to 150°C), maintaining dimensional accuracy within ≤0.05mm/m. Their dynamic sealing performance meets the stringent helium leak rate standard of <1×10⁻⁸ Pa·m³/s (IEC 62271-203), ensuring long-term gas containment in critical HV applications. Additionally, the bellows provide ±10mm axial displacement compensation and ±2° angular deflection capability, accommodating mechanical stresses in high-voltage switchgear.

A key innovation in our design is the precision interlayer gap control (±0.02mm tolerance), which minimizes stress concentrations and enhances fatigue life. Combined with solution heat treatment at 1050°C±10°C, the bellows demonstrate remarkable longevity, retaining over 90% of their initial burst pressure (≥8MPa) even after 1 million mechanical cycles. This ensures reliable performance in ultra-high-voltage circuit breakers, where repeated mechanical movement and high-pressure resistance are essential.