Refrigerant cylinder colour-coding

By Grant Laidlaw

All refrigerant containers, in addition to being marked with the type of refrigerant they contain, have a particular colour.

James asks: Grant, what is the situation with regards to refrigerant cylinder colour coding? In the past, and to my knowledge, each refrigerant has its own colour, but we find that this is no longer the case. We have, for example, R134a cylinders in our workshops that are blue, others are orange and an off white/grey. Yet they are all marked R134a. Are there no standards anymore? One could easily make a mistake and add the incorrect refrigerant with disastrous consequences.

Hi James, there are still standards, but not all suppliers’ cylinders conform to the codes.

James, in order to prevent mishaps, there are a variety of methods of identifying the type of refrigerant in a container – these are:

• Reading the identification on the container
• Looking at the colour of the container
• Measuring the refrigerant temperature and pressure
• Taking a sample for laboratory analysis

As mentioned already, all refrigerant containers, in addition to being marked with the type of refrigerant they contain, have a particular colour. The standard colours of some of the refrigerant containers are indicated in Table 1.

With regards to the confusion and lack of standardised colour codes on cylinders from suppliers, I did a bit of investigating and as can be seen in Figure 1, these are some of the disposable R32 cylinders available on the market.

This is a big problem and aside from possible catastrophic effects on the refrigeration system, this can in fact be dangerous.

As an example of a safety issue revolving around fire-fighters and other emergency personnel, with the new system they will know at a glance that if they see a grey cylinder they are dealing with a refrigerant and if it has a red band on it, they will know that it is flammable.

There is some movement to standardise the colour coding of cylinders.

It would seem that the Air Conditioning, Heating, and Refrigeration Institute (AHRI) Guideline N is gaining some traction. Although not enforced in South Africa, perhaps the powers that be will adopt this standard.

There is some work being done by the Department of Environment, Forestry, and Fisheries with regards to disposable cylinders.

Revisions to AHRI Guideline N, were first announced on June 28, 2016. They specify that all refrigerant containers should have the same paint colour (grey) to end confusion between similarly coloured cylinders.

Under the new system, refrigerant cylinders will be clearly marked as indicated in Figure 2. Refrigerants will be identified by the product number and colour printed on the cylinder. Guideline N is voluntary but generally followed by the North American industry. We will, no doubt, see similar changes to cylinders used locally.

If you have a situation where the refrigerant in the cylinder is unknown, or should you wish to verify the contents of a cylinder, a basic method would be to measure temperature and pressure to determine type of refrigerant from a temperature/pressure chart.

For every pure refrigerant there is a relationship between the temperature and the pressure (pure means that there must not be any air or other gas present in the container).

Refrigerant pressures at the same temperature mostly vary considerably and the pressure/temperature relationship is unique to each refrigerant. However, in some instances you will find that some refrigerants have more similar pressures at the same temperature.

In most cases if the temperature and the pressure of the refrigerant in the container are measured accurately, the type of refrigerant in the container can be determined. However, if there are two (or more) refrigerants in the container that have approximately the same pressure, further tests will have to be carried out.

Thanks for the question James. As I have said before: in terms of refrigerants, we are experiencing rapid global change and need to ensure our knowledge, procedures, legislation, and equipment are keeping abreast.

References:

• ACRA
• AHRI Guideline N 
  

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