Tagged: iso

Colour Coding

What is the importance of Colour Coding?

Quite often when we are correcting or helping companies set up their lubrication storage areas, we get asked a lot of questions regarding colour coding.

Colour_coding

Ideally, the concept of colour coding is to allow field personnel to easily identify and associate particular lubricants with their applications.

However, like most things in reliability, this can be customized to suit your organization. There are no hard and fast rules of using only yellow to represent hydraulic oils.

What if we had someone that was colour blind?

Usually, when we start colour coding lubricant storage containers, we include symbols and actual names of the lubricant. This helps to assist personnel in having a 3 point verification system.

First they can verify the colour, then the symbol and of course the name of the lubricant.

Names are crucial! Especially for varying viscosities (such as gear or hydraulic oils). For instance all gear oil would have the same colour and symbol but you wouldn’t want to put an ISO 100 gear oil in a gearbox suited for ISO 680.

ISO 4406

A lot of people get confused when reading the ISO 4406 rating. The rating specifies a range of the number of particles of certain sizes that can pass through 3 particular sized filters namely; 4micron, 6 micron and 14 micron filters respectively.

For instance; a rating of 13/11/8 indicates:

  • 13 represents 4000-6000 particles over the size of 4um
  • 11 represents a range of 1000-2000 particles over the size of 6um and
  • 8 represents a range of 130-250 particles over the size of 14um.

These values are actually the number of particles per milliliter. It does not mean that you have 13, 11 or 18 particles only in your oil, it's much more than that!

There are different ratings for different levels of cleanliness.

If your numbers are really high (25/22/19) then there’s definitely a high level of contamination!

Different components have different ISO cleanliness ratings. For instance, a roller bearing has a higher cleanliness target than a Variable Vane pump.

Understanding the ISO 4406 codes are crucial for determining the steps needed in “cleaning up” your system lubricants.

 

However, when we test for the cleanliness of an oil, there are a couple things that we need to consider:

  1. When testing, we have exposed the oil to the elements (highly dependent on the method of sampling)
  2. Results are not instantaneous (even with an onsite lab, there will be a timeframe between collecting the sample and processing it)

 

Since there are lag times involved, the value that is reported for the ISO4406 rating is never really truly representative of the oil. As such, when analysing the results of this test, it is important to consider that the actual value may potentially be higher than reported.

 

Matt Spurlock CLS, CMRP, MLE explains further about redefining the ISO code in his article entitled; "A Twist on Particle Evaluation: Redefining the ISO Cleanliness Code".