Galvanizing kettles — geometries, sizes and wall thickness
Four standard configurations plus custom work. The choice between them is driven mostly by bath depth and by how you handle dross.
| Metric | Imperial | |
|---|---|---|
| Length | 1.0 – 16.5 m | 3.3 – 54 ft |
| Width | 0.6 – 3.6 m | 2.0 – 11.8 ft |
| Depth | 1.2 – 3.2 m | 3.9 – 10.5 ft |
| Wall thickness | 40 / 50 / 60 mm | 1.6 / 2.0 / 2.4 in |
| Weight per kettle | 2 – 85 t | 2.2 – 94 short tons |
| Corner radius | 125 – 200 mm | 4.9 – 7.9 in |
| Operating temperature | 445 – 460 °C | 833 – 860 °F |
40 / 50 / 60 mm covers the great majority of baths. If your design calls for a heavier wall, ask — we will tell you what the works can roll and form for your dimensions rather than quote a number that does not apply to your kettle.
Choosing the geometry
| Geometry | Where walls meet the base | Advantage | Trade-off | Use it when |
|---|---|---|---|---|
| Full rounded corner | Radiused at every junction | Strongest weld geometry; bottom dross flows with no dead corner | Higher build cost | Bath deeper than 2 m |
| Rounded corner, flat bottom | Radiused between walls, square at the base | Corners do not trap dross; corner zinc less prone to local overheating | Dross can settle in the base corners | Bath 2 m and under |
Single or double flange on either geometry, depending on how your furnace is built and how the kettle is supported.
This is not a preference — it is a rule in BG/T 1501-2015 Table 4. Below 2 m depth, a flat bottom is the right answer and a full radius is money you do not need to spend. Above 2 m, the hydrostatic load makes the full radius worth it.
The standard configurations
Full rounded corner · double flange
Deep baths, heaviest duty. Widest bearing surface and the stiffest top edge.
Read more →Full rounded corner · single flange
Deep baths with a simpler furnace interface.
Read more →Rounded corner flat bottom · double flange
Shallow baths, higher throughput.
Read more →Rounded corner flat bottom · single flange
Shallow baths and compact furnaces.
Read more →Custom and oversized
Up to 16.5 m (54 ft) and 85 t. Tell us your largest workpiece.
Read more →
What every kettle gets, regardless of configuration
- Aluminium-killed low-silicon plate, Si ≤ 0.03 %Ultrasonically inspected plate-by-plate to GB/T 2970 Class III before cutting.
- All forming done warm, 850 – 900 °CCold bending locks residual stress into a vessel that will run at 450 °C for years.
- Electroslag welding, ISO 4063 process 72Full wall thickness in a single pass. No inter-pass interfaces.
- Weld metal specified to Si ≤ 0.03 %Grade 1 of BG/T 1501-2015 Table 10. Weld silicon decides where a kettle goes through first, so it is written into the order and evidenced by the welding consumable certificates that ship with the kettle.
- Ultrasonic testing of structural welds before dispatchGB/T 11345-2023 — identical (IDT) to ISO 17640:2018. Coverage and acceptance level are agreed with you and recorded in the inspection and test plan. Reports in English.
- No cruciform plate jointsParallel welds kept at least 0.5 m apart, per BG/T 1501-2015 §5.2.4.
- Full documentation packageIncluding the commissioning heat-up curve for your first firing.
Blast cleaned and painted in house. Surface preparation grade, coating system and dry film thickness are specified per order — send us your standard (most European buyers work to ISO 8501-1 for cleanliness and ISO 12944 for the coating) and it goes into the inspection and test plan rather than being left to works practice.
What we do not do
We do not build complete galvanizing lines. If you are planning a new plant from scratch, you need a line integrator, not us.
What we do is the kettle — the one part of the line you will replace several times over the life of the plant, and the part that decides how much of your production time you actually get.
Around it we supply what touches the bath: zinc pumps, dross removal, molten zinc storage, covers, dross shovels cut to your kettle’s corner radius, thermocouple wells.
Tell us what you need around the bath. Anything we cannot build ourselves we will say so about rather than quote it and sub-contract quietly.
Not sure which geometry?
Send the largest piece you dip and the throughput you need to hold. We will tell you which geometry, what depth, and how much zinc.