Metal Bellows Mechanical Seals
Edge-welded metal bellows seals for high-temperature, cryogenic and chemical duty — no elastomer secondary to harden, swell or hang up.
Edge-welded & formed · AM350 / Inconel / Hastelloy · API 682 Type B/C · −200 to 400°C+ · Custom
We are the manufacturer, not a reseller — we build in-house and supply at quantities that work for a distributor, an OEM or a maintenance department.
No elastomer
the secondary seal cannot harden or swell
High & low temp
hot oil, steam and cryogenic service
Hang-up free
no dynamic O-ring to stick on the shaft
Why metal bellows instead of a pusher seal
- Extreme temperature — there is no elastomer to harden, soften or take a set; the metal bellows is the spring and the secondary seal in one.
- No fretting, no hang-up — a pusher seal’s dynamic O-ring can stick or fret the sleeve; a bellows has no sliding secondary.
- Aggressive or polymerizing media — fewer soft parts to attack, and the bellows flexes through deposits that jam a pusher.
- Cryogenic and hot-oil duty — bellows alloys hold their spring rate where rubber simply fails.
New to the choice? Read pusher vs bellows seals.
What we supply
Edge-welded and formed bellows units, OEM-compatible or fully custom — at the quantities your operation actually orders.
Edge-welded bellows
Thin-leaf welded bellows for the widest temperature range and tightest axial response — the high-performance choice.
Formed bellows
Cost-effective formed bellows for moderate temperature and general high-temp water and oil service.
OEM-compatible & custom
Alloy and convolution selection (AM350, Inconel 718, Hastelloy C) machined to your pump and service, including obsolete designs.
Match the bellows to the duty
Construction and alloy follow temperature and media. The table is a starting point; send the service and we confirm the spec.
| Service | Construction | Alloy | Faces |
|---|---|---|---|
| Hot oil / thermal | Edge-welded | Inconel 718 | Carbon / SiC |
| Steam / condensate | Edge-welded | AM350 | SiC / SiC |
| Cryogenic | Edge-welded | Inconel | Carbon / SiC |
| Aggressive chemical | Edge-welded | Hastelloy C | SiC / SiC |
Go deeper: How bellows seals work · Selecting welded bellows seals.
Metal Bellows Seal FAQ
Edge-welded or formed bellows?
Edge-welded (thin welded leaves) give the widest temperature range and best axial response; formed bellows are more economical for moderate high-temp duty. We match it to your temperature and budget.
What temperature can bellows seals handle?
With the right alloy and faces, metal bellows run from cryogenic (around −200°C) to well above 400°C — far beyond any elastomer secondary.
Which alloy do I need?
AM350 for general high-temp, Inconel 718 for hot oil and higher stress, Hastelloy C for aggressive chemicals. We select it from your media and temperature.
Do you build to API 682?
Yes — Type B and Type C metal bellows cartridge seals to the standard, sized to your pump and service.
Source Metal Bellows Seals At Scale
OEM-compatible, custom-machined and private-label metal bellows seals built in-house to your spec, at low minimums. Send a pump model, a duty sheet or a sample and we’ll quote.