Pipe Marking Guide

Guide to the ASME / ANSI A13.1
Standards for the Identification of Pipes

Material Properties
Text Color on Field Color

Inherently Hazardous Materials
Extreme Pressure or Temperature
Radioactive
Corrosive or Caustic
Toxic or Creates Toxic Gas
Explosive or Flammable
Black on Yellow

Low Hazard Materials

Liquid or Liquid Mixture

Gas or Gaseous Mixture
White on Green

White on Blue
Materials for Fire Suppression
Sprinkler Water, Carbon Dioxide,
Foam, Halon, etc.
White on Red

 

Outside Pipe Diameter
Including Covering
Minimum Length of
Label Field Color
Minimum Height of
Letters
Inches mm Inches mm Inches mm
3/4 to 1 1/4
1 1/2 to 2
2 1/2 to 6
8 to 10
over 10		 19 to 32
38 to 51
64 to 152
203 to 254
over 254

8
8
12
24
32

203
203
305
610
813

1/2
3/4
1 1/4
2 1/2
3 1/2		 13
19
32
64
89


Place markers:

  • Near valves, flanges and changes in pipe direction.
  • At both sides of ceiling, wall or floor penetrations.
  • At any line entry point.
  • At frequent intervals on straight pipe runs. (Every 50' is typical.)

Locate pipe markers so they are visible from the point of normal approach.

This Guide is for General Information Purposes Only.
It is Not a Substitute for Review of Applicable Standards.
Provided by: Graphic Products, the leading supplier of industrial
labeling equipment and supplies - 1-800-788-5572

Please feel free to print this pipe marking guide.
Or request a printed, laminated copy. It's free and we'll be happy
to send you a copy of this pipe marking guide.

Additional information related to piping systems:
Carbon Steel Pipe Data || Pipe Markers Home