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Pipe Legends - Identification Scheme

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Color Scheme

Identification color scheme for piping systems based on ANSI A13.1 Standard for Pipe Identification:

ANSI A13.1 Standard for Pipe Identification - Colors
ClassificationColor Field and Legend
Inherently Hazardous Materials Flammable or Explosive Fluids Black text on Yellow background
Chemically Active, Toxic or Corrosive Fluids Black text on Yellow background
Extreme Temperatures or Pressures Black text on Yellow background
Radioactive Black text on Yellow background
Inherently Low Hazardous Materials Liquid or Liquid Admixture, Potable Water, Feed water ... WhiteText on Green background
Gas or Gaseous Admixture, Compressed air .. White Text on Blue background
Fire Quenching Materials Water, Foam, CO2, .. White Text on Red background

Size of Letters

ANSI A13.1 Standard for Pipe Identification - Size of Letters
Outside Pipe or Covering Size
Width of Color Band
Size of Letters
3/4" to 1 1/4" 8 1/2"
1 1/2" to 2" 8 3/4"
2 1/2" to 6" 12 1 1/4"
8" to 10" 24 2 1/2
> 10" 32 3 1/2"
  • 1 inch = 25.4 mm
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