Vacuum Degassing Chambers — 316L, Sealed & Helium Tested

A degassing chamber has to hold vacuum while being filled with whatever is evaporating off the product. That makes seal compatibility and cleanability the design drivers rather than the ultimate pressure.

What a degassing chamber has to survive

The chamber sees process vapour and condensate on every cycle, not just air. Solvent, electrolyte or resin vapour attacks elastomers, and condensate that pools in a corner becomes a contamination source. So the seal material has to be chosen against the process chemistry, and the internal geometry has to drain rather than trap.

Why 316L rather than 304

316L resists chlorides and a wider range of process chemistries than 304, and its lower carbon content means the weld heat-affected zone is less prone to sensitisation. For battery electrolyte work, where traces of moisture and electrolyte combine, that difference is worth the material cost.

Construction we use

A 316L shell with full-penetration TIG welds, internal surfaces electropolished to reduce both adsorption and particle retention, ISO-KF or ISO-K flanged ports for pump and gauge connections, and a demountable lid seal selected against the process vapour rather than against vacuum alone.

A representative project

We fabricated twelve custom 316L degassing chambers for a battery cell degassing process, with high-vacuum performance verified by helium leak testing, electropolished internal surfaces and precision ISO-KF flanges. The chambers were designed so the internal volume drains completely and can be cleaned between product changes without dismantling the shell.

Sizing

Chamber volume is set by the batch rather than by the pump: the chamber has to be large enough that the vapour released during the pump-down does not re-condense on the product. Where the batch is large, chambers are built as a horizontal cylinder with a full-length lid rather than a vertical pot, so loading does not require lifting product over a rim.

What we control in-house

304 / 316L stainless steel and 6061 / 5083 aluminium fabrication
Clean-environment TIG welding with full penetration and no micro-porosity
Helium mass-spectrometer leak testing to 1 × 10⁻⁹ mbar·l/s
In-house electropolishing and passivation — not subcontracted
Chamber bake-out to 150–400 °C for UHV outgassing control
Precision-machined ISO-KF, ISO-K and CF (ConFlat) flanges
Zeiss CMM verification to ±0.02 mm across large work envelopes
12 m gantry CNC machining — 12 m × 4 m × 2 m envelope
SEMI-referenced documentation and inspection protocols

Frequently asked questions

What is a vacuum degassing chamber used for?

Removing dissolved or entrained gas from a liquid or a solid under reduced pressure — battery electrolyte and cells before sealing, casting resins before they set, and potting compounds where a bubble would become a failure point.

Why 316L for a degassing chamber?

Because the chamber sees process chemistry as well as vacuum. 316L tolerates chlorides and a wider range of solvents than 304, and its lower carbon content reduces sensitisation in the weld heat-affected zone.

How is the chamber sealed?

With a demountable lid seal selected against the process vapour rather than against vacuum alone, and ISO-KF or ISO-K flanged ports for the pump and gauge connections. The seal material is the part most often chosen wrongly, because a compound that is fine in air may swell badly in solvent vapour.

Can the chamber be cleaned between products?

Yes, and it should be designed for it. We build internal geometry to drain completely and avoid crevices where condensate collects, so a change of product does not require dismantling the shell.

Do you build degassing chambers in other sizes?

Yes. Volume is driven by the batch. Small vertical chambers are used for laboratory and pilot work, and horizontal cylinders with full-length lids are used where the batch is large enough that lifting product over a rim is impractical.