Pipe Marking Infographic

Pipe marking standards are provided by both the ASME (American Society of Mechanical Engineers) and the ANSI (American National Standards Institute) Code A13.1.

Labels on pipes and valves provide important safety information. They inform employees, contractors, customers, and emergency response teams about the contents of the pipe, the hazard it poses, and the direction of flow through the pipe.

The following is a transcript of the Electrical Injuries Infographic:

Pipe Marking

ANSI/ASME A13.1 2007 Standard

Color Chart

FLAMMABLE Black on Yellow e.g.: Hydrogen

COMBUSTIBLE White on Brown e.g.: Canola Oil

TOXIC/CORROSIVE Black on Orange e.g.: Nitric Acid

FIRE QUENCHING White on Red e.g.: Fire Water

OTHER WATER White on Green e.g.: Boiled Water

COMPRESSED AIR White on Blue e.g.: Nitrogen

Defined by User
White on Black
White on Gray
White on Purple
Black on White

Pipe Marker Placement

Label placement in relation to point of normal approach

Size Chart

Outside pipe diameter w/ cover:

75" - 1.25"
1.5" - 2"
2.5" - 6"
8" - 10"
Over 10"

Minimum Length field color

8"
8"
12"
24"
32"

Min. letter height

.5"
.75"
1.25"
2.5"
3.5"

• Adjacent to changes in direction
• Adjacent to all valves & flanges
• Both sides of floor/wall penetrations
• Every 25' 50' on straight runs is typical