Overhead Cranes for Anodizing & Surface Treatment Lines
An anodizing line is a positioning problem before it is a lifting problem. The hook has to stop over each tank within a few millimetres, on a fixed cycle, in air that eats standard paint. This page sets out what that changes about the crane.
Why an anodizing line is hard on a crane
A treatment line moves racks of parts through a fixed sequence of tanks: degrease, etch, anodize, dye, seal, dry. The crane is the machine that moves them, and the cycle time of the line is set by how fast it can do it without spilling, swinging or missing the tank.
Three things make this different from general workshop lifting. The hook has to stop accurately over each tank rather than simply reach an area. The air above the tanks is acidic or alkaline, so a standard painted crane corrodes from the outside in. And the crane runs all shift, hundreds of lifts a day, which puts it in a higher duty class than its load weight suggests.
The configuration that fits
For most lines, a single girder overhead crane with a wire rope hoist is the right starting point: 1–10 t, span matched to the tank layout, hook height set so the rack clears the tank rim and any agitation equipment. VFD on hoist, trolley and long travel is not a luxury here — stepless control is what stops the rack swinging between tanks.
Where racks are heavy or long, or where two hooks are needed for a spreader, a double girder crane with a wider hook approach is the better answer. If the building cannot carry a runway on both sides, a semi-gantry crane can use one wall and one ground rail.
For automated lines, the crane can expose dry contacts or a Modbus interface to the line PLC, so tank positions and interlocks are handled by the line control rather than by the operator.
Corrosion protection is part of the specification
Standard workshop paint is not enough above an acid tank. We specify IP55 motors and panels, sealed bearings, stainless fasteners, drip covers over the hoist and trolley, and either hot-dip galvanizing or a multi-coat epoxy system with a stated dry film thickness. Details matter: no water traps in the girder, drainage holes where condensate collects, and a finish that can be washed down.
What we need before quoting
Send the rack weight including parts, the tank layout and the distance between tank centres, the height from floor to tank rim, the required cycle time per move, shifts per day, the site voltage, and what the air above the tanks contains. A photograph of the line and the building structure answers half the questions.
Typical configuration
| Capacity | 1–20 t typical |
|---|---|
| Span | 8–25 m |
| Lifting height | 4–12 m above floor |
| Duty class | A5–A6 |
| Hoist | Wire rope, VFD |
| Control | Pendant / remote / PLC interface |
| Protection | IP55, epoxy 200 µm or galvanized |
| Power supply | Site voltage, 3 phase |
These are typical ranges. The final figures depend on the tank layout, rack weight and required cycle time.
Questions we are asked
Can a standard workshop crane be used on an anodizing line?
Only if the duty, positioning and corrosion requirements are addressed. A standard crane with painted finish and single-speed control usually fails on cycle time first and corrosion second. We would normally specify VFD, IP55 protection and a coating system for the tank environment.
Single girder or double girder?
Single girder covers most lines up to about 10 t with moderate rack sizes. Double girder is specified for heavy or long racks, for two hooks or a spreader, and where hook height or hook approach is tight.
How do you stop the rack swinging between tanks?
VFD on all motions, a controlled acceleration and deceleration profile, and where necessary an anti-sway function. A fixed cycle with taught tank positions also helps more than most mechanical fixes.
Can the crane be integrated with the line PLC?
Yes. We can provide dry contacts for position and status, or a Modbus interface, so the line controller can call the crane to a tank and interlock with the process.
Related products and projects
Send us your anodizing or surface treatment requirement
Tell us the rack weight, tank layout, cycle time and environment — we reply within 24 hours.