Hoppers, cones and transition pieces look like simple sheet metal parts. In practice they are among the geometrically more demanding components in plant engineering.
Round has to meet rectangular. Two different diameters have to be joined. An outlet sits off-centre. A hopper has to empty well despite restricted space. And in the end every connecting dimension has to match the plant exactly.
stainlesstec makes customer-specific hoppers, cones, reducers and transition pieces to drawing and CAD data – as single parts, small batches or part of a complete assembly.
Many transition pieces join shapes that do not simply flow into one another. Typical tasks are:
round to round
round to rectangular and rectangular to round
differing diameters
differing rectangular cross-sections
eccentric transitions
angled outlets
conical tapers
asymmetric shapes
special geometries with multiple bends
The more complex the transition, the more important a clean flat pattern, bending sequence, forming and weld planning become. The question is not whether the shape can be drawn – it is whether it can be made precisely and repeatably.
Hoppers: when material has to be guided on
Hoppers connect vessels, machines or process stages. Depending on the application they have to:
guide bulk solids
carry liquids away
collect media
reduce a process cross-section
connect machines to one another
keep to a defined installation height
Wall angles, outlet position, transition radii and connection geometries are functionally decisive here. We make round, rectangular and bespoke hopper shapes to specification.
Cones: a simple shape, until it becomes part of a plant
Conical parts change a diameter or carry media on into another process stage. In production terms, the cone angle, material thickness, diameter, segmentation, weld position and connection geometry all matter.
On larger or more complex parts we build a cone up from several segments. Cutting and welding sequence are then planned so that the geometry stays within tolerance after joining.
Round to rectangular
Transitions between round and rectangular cross-sections occur in many technical systems:
air and extract systems
machine connections
process pipework
filter systems
vessel outlets
conveying and dosing systems
It is here in particular that multiply curved or multiply bent surfaces arise. That calls for a clean digital flat pattern and a precise production sequence.
Eccentric transitions
Not every connection runs on a common centre line. Where pipes, machines or vessels are offset in space, eccentric transitions arise – and with them:
differing side lengths
unequal angles of inclination
asymmetric shell surfaces
more demanding weld edges
higher demands on fit
This is exactly where CAD-based production planning pays off: the design becomes a defined flat pattern with a clear production sequence.
From CAD model to sheet metal geometry
With complex transition pieces, much of the value is added before production proper begins. The three-dimensional part has to become suitable individual pieces. The points considered are:
flat pattern – how does the 3D geometry become a blank that can be made?
bending sequence – which forming step has to come first?
weld edges – where does it make sense to join the individual pieces?
material behaviour – which radii and forming operations are possible in this material?
tolerances – which dimensions are critical for the later connection?
Precision here begins not with welding but with the digital preparation.
Fewer segments are not always better. Making a complex part from a single sheet sounds ideal – in practice, sensible segmentation often brings better formability, easier tool access, better-controlled welds, less distortion, better surface quality and more economical production. The right division follows from geometry, material and quantity.
Welding and distortion
Hoppers and transitions are often made from thin or large-area sheet. Long welds therefore affect the shape more than they would on more solid parts. Welding sequence, clamping, heat input and seam position belong in the production plan.
A range of welding processes and experienced specialist welders are available for this. The aim is not just a clean seam but a finished part that holds its dimensions.
Stainless steel and aluminium
Depending on the field of use, we make hoppers, cones and transitions in stainless steel – for food, process, machine and demanding technical applications – or in aluminium, where low weight or particular technical properties are called for.
Material, thickness and surface requirement shape the whole production strategy.
Surfaces to suit the application
On hoppers and transitions the surface is often functionally important. Depending on the application, what counts is:
good cleanability
low product adhesion
corrosion resistance
high-grade visible surfaces
a defined grinding direction
smooth transitions
In food and process applications it should be settled early which areas are in product contact. We finish high-grade stainless steel surfaces in our own surface finishing department, and the components concerned are made in our segregated production area.
When material has to flow
With bulk solids and food processes in particular, it is not only the outer shape that governs material transport but the inside of the part as well. Wall angles, transition radii, weld execution, surface condition and outlet cross-section all matter.
The process design is yours to supply. We realise the defined geometry so that it can be made cleanly and repeatably.
Typical applications
Food processing technology
Hoppers, outlets and transitions for dosing, conveying and production plant.
Connecting pieces between machines, pipework and process components – including transitions between different duct cross-sections in air and extract systems.
Review the CAD data – analyse geometry, material and connecting dimensions
Develop the flat pattern – turn the 3D geometry into pieces that can be made
Laser cut – cut contours and connection areas precisely
Bend and form – the individual faces take on their geometry
Weld – join the segments and create the final shape
Straighten and finish – complete geometry and surface to specification
Inspect – check connecting dimensions and key geometries
Single part or small batch
Many transition pieces are first made for one particular machine. Later, further plants are built, variants are needed, spares are ordered or similar geometries are adapted.
With digital manufacturing data, components developed once can be made again repeatably. A bespoke build thus becomes a controlled small batch.
What we need for your enquiry
STEP data or drawing
inlet and outlet cross-section
dimensions
overall length
material
material thickness
connection geometries
flanges, if any
surface requirements
product-contact areas
quantity
critical tolerances
With complex geometries, 3D data are particularly helpful.
Two cross-sections, one connection that fits. We make the geometry in between.
Hopper, cone, reducer or complex round-to-rectangular transition: send us your design.
Our production planning team will assess how the geometry can sensibly be developed, formed, welded and made repeatably.
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.
