Product Overview
The Formed Metal Bellows Assembly is manufactured from seamless SS316L tubing using precision hydroforming and mechanical forming processes. Unlike edge welded bellows — which are built up from individually welded diaphragms — formed bellows are produced from a single continuous tube, resulting in higher structural strength, superior pressure resistance, and a more cost-effective price point for medium-vacuum and industrial applications where UHV performance is not required.
This product fills the gap between low-cost elastomer connectors and premium UHV edge welded bellows. It delivers reliable axial and lateral motion compensation for vacuum pump connections, automation equipment, and industrial vacuum systems where the budget matters but reliability cannot be compromised. For a detailed comparison of formed vs. edge welded technology, see our Technical Guide which includes a side-by-side performance table.
Key Features
- Seamless tube construction — no circumferential weld seams; the continuous grain structure provides inherent pressure vessel integrity and eliminates weld-related leak paths
- Higher burst pressure than equivalent edge welded bellows — typically 3-4x rated working pressure, making it the safer choice for positive pressure applications
- Reliable multi-axis compensation — axial stroke of ±6–10mm plus lateral and angular compliance for absorbing misalignment and thermal expansion in industrial piping
- Cost-effective for medium vacuum — ideal for 10⁻⁶ to 10⁻⁸ mbar applications where UHV (<10⁻⁹ mbar) edge welded bellows would be over-specified
- Proven fatigue life of 100,000+ cycles under rated conditions — sufficient for most industrial automation duty cycles
- Standard flange interface — ISO-K, ISO-F, and ANSI flanges for plug-and-play integration with off-the-shelf vacuum components
Technical Specifications
- Type: Formed Metal Bellows Assembly (hydroformed / mechanically formed)
- Material: SS316L Stainless Steel — see Material Selection Guide for alloy options
- Manufacturing Process: Hydroformed or mechanically formed from seamless tube stock
- Vacuum Level: 10⁻⁶ to 10⁻⁸ mbar (medium to high vacuum; not recommended for UHV <10⁻⁹ mbar)
- Operating Temperature: -196°C to +300°C
- Axial Stroke: ±6–10mm (compression-dominant; extension limited to ~15% of free length for formed bellows)
- Cycle Life: 100,000+ cycles at rated stroke and pressure
- Pressure Rating: Up to 15 bar positive pressure (size-dependent)
- Surface Finish: Standard industrial / Passivated
Typical Applications
- Industrial vacuum systems — vacuum holding and pick-and-place systems, packaging machinery, material handling
- Vacuum pump connections — roughing and booster pump isolation, foreline flexible connectors
- Automation equipment — linear actuator boot seals, rod wiper replacements in dusty factory environments
- Mechanical compensation systems — thermal expansion joints, pipe misalignment correctors in non-UHV service
- Semiconductor auxiliary equipment — sub-fab roughing lines, facility vacuum distribution, abatement system connections
