What are the ANSI standards for pipe color codes?

The American National Standards Institute, or ANSI, is a private organization that creates and publishes standards for a wide range of different products, services, systems, and personnel. One of the sets of standards that they have had in place for many years is focused on pipe markings and labeling.

Pipe labels are used primarily in commercial and industrial environments to help ensure those working with or around any type of pipes knows what is contained within them. This is important for employee safety, efficient maintenance, and even emergency responders. While pipe markings can include a lot of information on them, one of the most important aspects of the ANSI standards is the colors that are used.

ANSI Pipe Color Codes

Using color coding for pipe markings helps ensure those who work around pipes are able to quickly see the labels and identify them, even from a distance. Recognizing a color is much easier to do than being able to read the text that is placed on the labels, especially during high stress or emergency situations.

The following are the primary color codes that are recommended by ANSI for pipe markings:

  • Fire Quenching Fluid – Fire quenching fluids should be marked with a red label that has white lettering.
  • Toxic/Corrosive FluidsToxic and/or corrosive fluids use an orange label with black text.
  • Flammable/Oxidizing Fluids – All flammable and/or oxidizing fluids need to be on a yellow label with black text.
  • Combustible Fluids – Fluids that are combustible should be on a brown label with white text.
  • Water – Almost all types of water, including potable, boiler feed, cooling, and other, should be marked using a green label with white lettering.
  • Compressed Air – Compressed air is identified using a blue label with white markings.

ANSI recognizes that there are many situations where the above-mentioned colors won’t fully cover every type of fluid or gas that travels through pipes. With this in mind they have also reserved several color configurations for ‘to be defined by the user’ so that custom labels can be used throughout facilities. The reserved colors are purple labels with white letters, white labels with black letters, gray labels with white letters, and black labels with white letters.


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