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ANSI Color Codes
For Pipe Marking

free ansi pipe marking
ANSI Standards for Pipe Marking

Written by Steve Hudgik

It is estimated that 90% of all piping uses the ANSI A13.1 standard for pipe marking. It is the pipe marking standard nearly everyone in the workplace should be familiar with.

The ANSI color codes are an important part of the standard. Color is one of the most effective means of communicating.  The ANSI color codes for pipe marking provide a standardized color coding system that identifies the general type of material in the pipe and the potential hazard of presented by the pipe contents.

ANSI A13.1 Standard Pipe Marker Color Codes

The ANSI color codes use six predefined colors. They are the first six colors in the chart below.  An additional four colors are provided for user defined substances.  When a pipe contains a mixture, then the color code should be selected based on the most hazardous material.

Pipe Contents

Color Scheme

Fire-quenching fluids White text on red
Toxic and corrosive fluids Black text on orange
Flammable fluids Black text on yellow
Combustible fluids White text on brown
Potable, cooling, boiler feed, and other water White text on green
Compressed air White text on blue
User-defined White text on purple
User-defined Black text on white
User-defined White text on grey
User-defined White text on black

The ANSI color codes use a text color that provides a high contrast with the background.  The text color should be considered as a part of the ANSI color code and should not be varied from what is given in the code.

ANSI Color Codes - Pipe Label Placement

There should be sufficient pipe markers such that a pipe marker can be seen from any normal angle of approach. For example, overhead pipes should have pipe makers that are below the center line of the pipe. The objective is to have pipel abels located such hat pipes can be identifiable by an emergency responder, who has never been in the facility, from any place it is possible to see the pipe. pipe marking examples

The ANSI pipe marking code requires that pipe markers be placed:

  • Adjacent to all valves and flanges
  • Adjacent to all changes of direction
  • On both sides of wall or floor penetrations
  • At regular intervals on straight runs (50' is the acceptable maximum spacing, but closer spacing might be necessary for pipe marker visibility.)

ANSI Color Codes - Label Size

Pipe marker labels must be large enough to be clearly visible.  Color coding does no good if the color code labels are too small to be seen.  The larger the pipe diameter, the bigger the label needs to be.  The ANSI pipe marking code gives the following minimum label sizes:

Outside Pipe Diameter (including insulation)

Minimum Length of Label Color Field

Minimum Letter Height

Inches mm Inches mm Inches mm
.75–1.25* 19–32 8 203 .5 13
1.5–2 38–51 8 203 .75 19
2.5–6 64–152 12 305 1.25 32
8–10 203–254 24 610 2.5 64
>10 >254 32 813 3.5 89

Pipe Marking Color Reference Guide

A complete reference guide to Pipe Marking

If needed for good visibility larger labels may be used. Specialty labeling materials, such as reflective labeling supplies, may also be used to enhance the visibility of pipe markers.

Are you ready to do pipe marking? Call 1-888-326-9244 today and ask about our special pipe marking kits. You'll get a DuraLabel printer and all the supplies needed for making pipe markers that are fully compliant with the ANSI color codes.


The information presented in this document was obtained from sources that we deem reliable; Graphic Products does not guarantee accuracy or completeness. Graphic Products, Inc. makes no representations or warranties of any kind, express or implied. Users of this document should consult municipal, state, and federal code and/or verify all information with the appropriate regulatory agency.

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