Surface Treatment – Ladders, Trays and Baskets 

By on

eng_galvano_no
Image Source: Galvano

Steel ladders, trays and baskets form the backbone of cable containment systems. Often these items need some form of surface treatment to prevent corrosion due to the installed environmental conditions. The type of surface treatment required depends on the installed environment and corrosive conditions present.

 

 

 

The standard ISO 12944 defines six categories of corrosive atmospheric environment.  The table below lists the classification and gives some.

Classification Examples
Cat. Corrosion Level Exterior Interior
C1 very low -

Heated buildings with clean
atmospheres, e.g. offices, shops, schools, hotels.

C2 low Atmospheres with low level of pollution. Mostly rural areas. Unheated buildings where condensation may occur, e.g. depots, sports halls.
C3 medium Urban and industrial atmospheres, moderate sulphur dioxide pollution. Coastal areas with low salinity. Production rooms with high humidity
and some air pollution, e.g. food-processing plants, laundries, breweries, dairies.
C4 high Industrial areas and coastal areas with moderate salinity. Chemical plants, swimming pools, coastal ship- and boatyards.
C5-I very high (industrial) Industrial areas with high humidity and aggressive atmosphere. Buildings or areas with almost permanent condensation and with high pollution.
C5-M very high (marine) Coastal and offshore areas with high salinity. Buildings or areas with almost permanent condensation and with high pollution.

 

The table below list common surface coatings typical application areas:

Surface Coating Description Application
Electroplated zinc
Standard EN 12 329
Zinc coating of steel by immersion in electrolyte and using electric current. Corrosion Class C1
Indoor & normal environments
Pre-galvanised
Standard BS EN 10327
Steel sheets or wires coated by immersion molten zinc, prior to manufacture . Corrosion Class C1, C2
Indoor and low corrosion exteriors
Hot dip galvanised
Standard BS EN ISO 1461
Manufactured part immersed in molten zinc. Results in a thick coating Corrosion Class C3, C4
Exterior, chemical and marine environments
Stainless steel
Standard BS EN 10088
Naturally offers corrosion protection. Corrosion Class C5-I, C5-M
Chemical, marine and food production
Thermoplastic coating Part coated by melted plastic powder. Aggressive environments

 

Note: many other specialist (proprietary) coatings exist; zinc-aluminium, polyester zinc etc.  These typically would have specialist applications.

Note: Zinc coatings protect parts as both a coating and sacrificial anode. The sacrificial anode enables small scratches to repair themselves.  The life of the coating is directly proportional to it's thickness – twice as thick and it will last twice as long



Steven McFadyen's avatar Steven McFadyen

Steven has over twenty five years experience working on some of the largest construction projects. He has a deep technical understanding of electrical engineering and is keen to share this knowledge. About the author

myElectrical Engineering

comments powered by Disqus

  1. naban's avatar naban says:
    5/30/2012 12:30 PM

    Powder coating also could be done.


Comments are closed for this post:
  • have a question or need help, please use our Questions Section
  • spotted an error or have additional info that you think should be in this post, feel free to Contact Us



8 Steps to Low Voltage Power Cable Selection and Sizing

A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...

DC Motor Operation

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

Motor Insulation

Insulation on a motor prevents interconnection of windings and the winding to earth.  When looking at motors, it is important to understand how the insulation...

How to Calculate Motor Starting Time

Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...

Cable Trumps

Bored at work and would rather be playing trump card game with you son. The next best thing (or not) maybe the online cable trump card game from AEI Cables...

Our internet address and Vanity URLs

Visitors who like to type web address rather then click menus may be interested in how our URL structure works.

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

Arc Flash Calculations

Working in the vicinity of electrical equipment poses an hazard. In addition to electric shock hazard, fault currents passing through air causes Arc Flash...

Laplace Transform

Laplace transforms and their inverse are a mathematical technique which allows us to solve differential equations, by primarily using algebraic methods...

Thermoplastic and Thermosetting Insulation

While there are a vast array of cable insulation materials, these are often divided into two general types; Thermoplastic or Thermosetting. For example...

Have some knowledge to share

If you have some expert knowledge or experience, why not consider sharing this with our community.  

By writing an electrical note, you will be educating our users and at the same time promoting your expertise within the engineering community.

To get started and understand our policy, you can read our How to Write an Electrical Note