Product Overview
The Medium-Large Round Flange Edge Welded Bellows bridges the gap between compact general-purpose bellows and heavy industrial expansion joints. With larger flange diameters and a robust multi-convolution diaphragm stack, this bellows handles higher pressure differentials — up to 10 bar positive pressure — while still delivering the axial and angular compliance needed for vacuum system integration. It is the go-to choice for medium-scale vacuum coating machines, industrial drying systems, and vacuum heat treatment furnaces.
Despite the larger form factor, every unit benefits from the same micro-plasma edge welding process and individual helium leak testing that define Alpha Technology’s quality standard. The increased wall thickness and optimized convolution profile provide higher buckling resistance under external pressure without sacrificing flexibility. For exact dimensional options, see the medium-large range in our AT-Series Catalog.
Key Benefits
- Higher structural strength from larger flange geometry — handles up to 10 bar positive pressure and full vacuum simultaneously, ideal for systems that cycle between pressure and vacuum
- Enhanced diaphragm design with optimized convolution depth distributes stress evenly, achieving 1 million+ cycle fatigue life even under combined axial, angular, and pressure loading
- Excellent multi-axis compensation — ±10–15mm axial stroke plus angular and lateral compliance, absorbing thermal expansion in rigid vacuum piping networks
- Standard flange interface in ISO-K, ISO-F, and CF formats — drop-in compatible with major vacuum component manufacturers
- Long-life, low-maintenance design — all-metal, non-wearing construction eliminates the periodic seal replacement required by elastomer-based flexible connectors
Technical Specifications
- Flange Type: Medium-Large Round Flange (ISO-K, ISO-F, CF; custom bolt patterns available)
- Material: SS316L Stainless Steel — upgrade options in Material Selection Guide
- Vacuum Level: 10⁻⁸ mbar (standard); UHV 10⁻¹⁰ mbar with copper gasket option
- Operating Pressure: Up to 10 bar positive pressure (internal); full vacuum service (external)
- Operating Temperature: -196°C to +350°C
- Axial Stroke: ±10–15mm
- Angular Deflection: ±6°
- Cycle Life: 1,000,000+ cycles at rated stroke and pressure
- Surface Finish: Standard / Electropolished / Passivated
Typical Applications
- Medium vacuum coating machines — thermal evaporation, sputtering, and PECVD systems for optical and decorative coating
- Industrial vacuum drying equipment — transformer oil purification, pharmaceutical freeze-drying, food vacuum dehydration
- Vacuum heat treatment furnaces — brazing, sintering, and annealing furnace vacuum connections
- Semiconductor manufacturing equipment — batch process chamber exhaust and roughing lines
- Research vacuum systems — space simulation chambers, large-volume vacuum test facilities
