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



Dielectric loss in cables

Dielectrics (insulating materials for example) when subjected to a varying electric field, will have some energy loss.   The varying electric field causes...

Copyright Infringement

myElectrical does not support or promote the use of copyrighted material without the copyright owner's consent. If you believe that material for which...

HTML Symbol Entities

HTML supports a variety of entity symbols which can be entered using either numbers or an entity name.  The number or name is preceded by the ‘&’ sign...

The ac resistance of conductors

In a previous article I looked at the dc resistance of conductors and in this article we turn our attention to ac resistance. If you have not read the...

Sony Pocket eBook Reader

For the past few years I have reading eBooks on my HTC touch phone. On and off I have debated buying an eReader and recently purchased a Sony PRS-300 ...

Cables for MV Power Distribution - Earthed versus Unearthed Systems

Power cables can basically be classified into earthed and unearthed cables, where earthed and unearthed refer to the application for which the cable is...

What is a rectifier transformer?

I've recently come across this question a couple times browsing the internet. Decided to give a quick answer here. A rectifier transformer is a transformer...

What is LED?

Light Emitting Diodes (LED ) are increasing gaining favour in both the domestic and commercial sectors; due to their efficiency, sustainability and durability...

New Mail Chimp

We've been sending out Newsletters on a regular basis for a few weeks now. To do this we have been using Google's Feedburner service. While Feedburner...

IEEE Winds of Change

IEEE TV has a part series of videos on wind power and it's implication. For a really good overview to the technologies and issues around wind power, these...

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