A vacuum chamber is more than a closed vessel. The deeper the vacuum required, the more strongly material, welds, surface, design detail and cleanliness govern how the whole chamber behaves.
stainlesstec makes customer-specific vacuum chambers and vacuum components in stainless steel to drawing and CAD data – from the one-off to the recurring special design. In doing so we combine vessel and welding expertise with high-grade stainless steel processing, surface finishing and project-specific testing.
Stainless steel · special geometries · welded assemblies · flanges and connections · high-grade surfaces
The vacuum required defines the design
A simple chamber for technical vacuum is a different matter from a system for high or ultra-high vacuum. So at the outset we establish:
the working pressure required
chamber dimensions
material
pump ports
measurement and sensor ports
number and position of flanges
temperature range
bake-out temperature, where applicable
surface requirements
permissible leak rate
test methods
cleanliness requirements
Vacuum technology therefore starts not with the vessel but with the specification.
Under vacuum the surface becomes part of the system
At atmospheric pressure, small quantities of gas on a metal surface hardly matter. Under vacuum they become decisive: gases and moisture bound to surfaces are released again and affect how quickly and how deeply a chamber can be evacuated.
In demanding high-vacuum applications, material, surface and cleaning are therefore especially important. For production that means the surface of a vacuum chamber is not merely a finish but a functional part of its vacuum performance.
Welds without hidden volumes
A vacuum-tight weld has to be mechanically sound, but the design around the weld counts too. Unfavourable overlaps or doubly welded areas create small trapped cavities. The gas held in them seeps into the chamber only slowly and behaves like a leak: a virtual leak.
On demanding chambers, inside welds and the avoidance of gas-trapping double seams are therefore standard design principles. Welding for vacuum service thus begins at the design stage.
Ports have to suit the chamber
A vacuum chamber rarely consists of shell, bottom and lid alone. Typical interfaces are pump flanges, gauge ports, viewports, sensor connections, feedthroughs, valve ports, pipe stubs and fixing points.
Position, orientation and welding sequence have to be exactly right if the chamber is to fit the system later without rework. With many ports, planning the work becomes demanding: where can we weld? Which seam will still be accessible later? How do we limit distortion? Which flanges have to stay precisely aligned? This is where the experience of our specialist welders counts.
Round, rectangular or bespoke
A vacuum chamber does not have to be cylindrical. Depending on the system, the options include:
rectangular chambers
cubic housings
round vessels
combined geometries
chambers with large doors or lids
bespoke special shapes
For this we combine laser cutting, CNC bending, roll bending and a range of welding processes in one coordinated chain. Geometrically complex chambers can thus be built from your data as well.
Thin walls, heavy loads
One characteristic of vacuum vessels is easily underestimated: the pressure acts from the outside. At a differential of around one bar, a large area already carries a considerable total load. Large flat walls are therefore more demanding structurally than their material thickness suggests.
Depending on the design, that calls for reinforcements, ribs, suitable wall thicknesses, dished surfaces or adapted frame structures. The structural and vacuum design follows your specification – we take care of putting it into production.
Stainless steel for vacuum chambers
Austenitic stainless steels are widely used for vacuum chambers: they weld well, resist corrosion and suit demanding vacuum applications. Depending on the application, various stainless grades and in some cases aluminium alloys come into consideration.
Which grade is needed is decided by the application. We therefore need an unambiguous material specification, including any material certificates required. More under Materials.
Segregated production protects high-grade surfaces
Clean stainless steel surfaces matter particularly in vacuum work. We process stainless steel and aluminium in a segregated environment with no contact with other types of steel. That lowers the risk of iron contamination and allows the surface condition to be controlled across several operations.
Depending on the specification, further surface treatments or cleaning processes can follow. More under Segregated stainless production.
Surfaces to requirement
Vacuum chambers come with very different surface requirements: ground surfaces, a defined roughness, glass-bead blasted areas, or pickled and passivated surfaces.
Which is appropriate depends on the vacuum level required and on the application. We are equipped accordingly for mechanical surface finishing. Where requirements go further, the surface condition and any post-treatment should be defined before production begins.
Tightness has to be measurable
With a vacuum chamber, “looks tight” will not do. Depending on the application, defined evidence is required. The methods range from pressure and tightness testing through to helium leak testing on more demanding vacuum systems.
We carry out pressure and tightness tests on assemblies. Which leak rate and which test method are required belongs in the specification; more extensive vacuum and helium leak testing we arrange per project.
From sheet metal to vacuum chamber
Review the specification – bring together geometry, material, vacuum level, ports, surface and test requirements
Plan the production sequence – fix cutting, forming, flange positions, welding sequence and fixtures
Build the chamber – make shell, walls, frame, flanges and ports and weld them into an assembly
Finish the surface – produce internal and external surfaces to specification
Test – check dimensions, geometry and the agreed tightness requirements
Document – assign the project’s material and test records to the component
Typical applications
High technology, metrology & research
Test, inspection and experimental chambers, plus vacuum housings for analysis, sensor and test systems, all to customer design.
Vacuum chambers are rarely catalogue products. Prototypes, pilot plant and special machines need individual geometries and ports – often just once, to begin with. Later, further systems or variants grow out of them.
With CAD-based production planning, a chamber developed once can be built again repeatably and altered under control. That makes us a good fit for development projects and small batches.
What we need to assess a project
STEP data and drawing
chamber dimensions
material
wall thicknesses
working pressure, or the vacuum level required
permissible leak rate
flange systems and ports
pump connection
measurement and sensor feedthroughs
temperature range
bake-out conditions, where applicable
surface requirements
cleanliness requirements
test methods
documentation required
quantity
The more precisely these requirements are defined, the better the manufacturing and testing process can be matched to them.
Under vacuum every detail counts. So we look at the whole chamber.
Are you planning a vacuum chamber or a vacuum-tight special component? Send us the CAD data, the specification and your requirements for surface and tightness.
Production planning and welding engineering will assess how a suitable manufacturing process can be developed from them.
Let’s talk about your project.
Send us your drawing or CAD data by email – together with material, batch size and your requirements. We will come back to you with a sound assessment.
