Pipe color codes UNI 5634-97 standard

Here are the main options for the UNI 5634-97 standard, i.e. the colours in which the pipe labels are differentiated:

Redwith white writing. This red label with white characters is used for all liquids that extinguish fire, such as water, for example;

Greenwith white lettering. The use of a green label with white lettering means that the pipe contains potable water. It could be used for cooling, boiler feeding or even for fountains or sinks;

Greywith black writing it refers to steam or heated water;

Blueorsky bluewith black writing. Blue labels with black writing are used for pipes carrying compressed air;

Brownwith white characters. This option is valid for all combustible and flammable liquids and mineral oils;

Yellowochre with black characters. This option is used for all pipes containing gases in the gaseous or liquid state (excluding air);

Orangewith white lettering. Orange labels with white lettering are for toxic or corrosive liquids. Most acids will need to use this type of tube marking;

Violawith white writing it refers to all alkalis;

Blackwith white writing for all other fluids;

Yellow with black writing for other hazardous fluids;

Whitewith black writing for comburents.

ANSI/ASME Standard Pipe Color Codes

The ANSI/ASME pipe color codes, unlike the UNI standard, also provide several user-defined pipe color combinations. This is important because it allows facilities to plan for certain pipes that do not fit into the normal standards. It is important to remember, however, that whenever you use user-defined pipe markings, people who have not been sufficiently trained will not know what they mean.

The user-defined color options are:

• Purple with white writing;
• White with black writing;
• Grey with white writing;
• Black with white writing.

One of the most effective ways to ensure that people in the facility always know what each color label means is to post pipe color code diagrams.