Electrogalvanising plant – conditions for acceptance of a structure

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Chemical composition

Electrogalvanising enables coating of structures made of steel with a silicon (Si) content of less than 0.03% or between 0.15% and 0.25% with an anti-corrosion layer of zinc.

Surface condition

The surface of the structure should be free from scale, thick rust, weld spatter, welding slag, silicon scouring agents, paint, grease and oil contamination.

Structural features

Suspension line:

  • The structures should be suitable for suspension by hangers under the crosshead.
  • The structure geometry should allow free inflow of processing baths to all spaces and their free outflow.
  • Suspension line:

    The structure overall dimensions must be less than or equal to the following dimensions: 2.8 x 0.8 x 1.8 m (length x width x depth).

    When two dimensions are close to the limit dimensions, prior consultation is required.

    Maximum load weight up to 600 kg per crosshead, maximum load size up to 1200 dm2 per crosshead.

 

  • Drum-mounted line:
    Minimum load of 20 kg per drum

Vent holes

Structures made of closed-section elements should be provided with vent holes to allow the free inflow of processing baths during immersion and their free outflow during the emergence of the structure on the individual stages of the process.

The vent holes can be made as triangular or semicircular cut-outs in the profile walls.

The following diagrams illustrate the layout of the vent holes.

The table below indicates the size and number of vent holes in the elements of the structure.

Internal dimensions of the closed profile in mm less than:

The minimum diameter of holes in mm at opposite ends of the profile and their number:

round square rectangular 1 2 3
15 15 20 x 10 8
20 20 30 x 15 10
30 30 40 x 20 12 10
60 60 80 x 40 20 12 10
80 80 80 x 60 20 18 12
100 100 120 x 80 25 20 12
120 120 160 x 80 30 25 16
160 160 200 x 120 40 25 16
200 200 260 x 140 50 30 16

The vent holes can be made as triangular or semicircular cut-outs in the profile walls.

The following diagrams illustrate the layout of vent holes.