Mechanical Seal Range
Edge Welded Metal Bellows Seals
Hydraulically balanced bellows seals engineered for extreme temperatures, aggressive chemistry and the duties where pusher-style seals quietly fail. From cryogenic -212°C up to 425°C, in stainless, Inconel and Hastelloy™.
Why Edge Welded Bellows Seals Solve Problems Pusher Seals Can't
Edge welded metal bellows mechanical seals have earned their place because they remove the two weakest links in a conventional pusher seal: the dynamic O-ring and the spring exposed to product. The result is a seal that tolerates thermal shock, chemical attack and shaft misalignment far better than its rubber-dependent cousins.
They are the standard answer when temperatures, fluids or alignment conditions sit outside the safe envelope of a standard cartridge seal, and when API 682 / ISO 21049 demands a hydraulically balanced design.
Four Engineering Advantages
Extreme Temperature Range
Operating envelopes from -212°C (cryogenic) up to 425°C, well beyond the limits of elastomer-dependent pusher seals.
Inherently Hydraulically Balanced
Mean effective diameter cuts through the bellows insert, reducing face load, friction and heat generation. Longer seal life, lower energy draw.
No Dynamic O-Ring
Eliminates hang-up from heat, chemical attack, shaft fouling and fretting. More forgiving on axial movement and vibration.
Diverse Metallurgy
Stainless grades, Inconel, Hastelloy™ and other alloys. Heat-treated bellows cores retain spring rate at elevated temperatures.
Formed Bellows vs Edge Welded Bellows
Not all metal bellows are equivalent. The manufacturing route determines flexibility, material choice and life expectancy.
| Formed Bellows | Edge Welded Bellows |
|---|---|
| Metal tubes expanded inside a mould under hydraulic pressure. | Individually formed diaphragms welded together with a precise microscopic process. |
| Typically lower cost per piece. | Higher performance in a smaller package. |
| Thick walls, high stiffness, limited flex. | Dramatically greater flexibility and range of motion. |
| Restricted to high-elongation metals such as brass. | Wide alloy choice, stainless, Inconel, Hastelloy™ and other corrosion-resistant grades. |
| More vulnerable to dents and nicks. | Resistant to handling damage in service. |
Common Applications
Edge welded bellows seals replace pusher-style seals across high-stakes duties where downtime is unacceptable.
- Chemical processing
- Oil & gas
- Heat transfer fluid systems
- Wastewater treatment
- Mixers, agitators, centrifuges
- API 682 / ISO 21049 compliant installations
Got a Pusher Seal That Keeps Failing?
Send us your duty conditions, temperature, pressure, fluid, shaft size, and we'll tell you honestly whether an edge welded bellows seal is the right upgrade, or whether something simpler will do the job.