A Guide to ANSI Pipe Marking Standards

pipe marking standardsPipe marking is essential to workplace safety and ANSI and ASME has provided guidelines for the proper labeling of pipes. ANSI/ASME A13.1 (recently revised in 2015) is the most common standard for pipe marking in the United States. The scope of this standard includes identification of the pipe, what pipe labels should look like and where the markers go. Following the ANSI/ASME standard will keep you in compliance with regulations and ensure those working on or around pipes are kept safe.

ANSI/ASME A13.1 specifies two types of identification on a pipe label: a primary and a secondary. The primary means for identification is the printed text of the pipe’s contents and arrow on the label that indicates the direction of flow. The secondary means of identification is the colors used for the label. The approved color combinations and what they signify are as follows:

  • Yellow label / Black lettering: Flammable liquids and gases.
  • Green label / White lettering: Potable water.
  • Blue label / White lettering: Compressed air.
  • Red label / White lettering: Fire quenching fluids.
  • Orange label / Black lettering: Toxic or corrosive fluids.
  • Brown label / White lettering: Combustible fluids.

Additionally, the standard identified four color combinations (purple and white, white and black, grey and white, and black with white) as “user defined.” This means the facility can determine and assign meanings to contents that may not exactly fit in with the normal standards.

When looking where to place pipe labels, ANSI/ASME provides guidelines. Labels should be placed on the pipe where it is visible from a normal approach. For instance, if a pipe is near the ceiling, adhering a label on the other side of the pipe will be more visible. At valves, flanges, and changes in pipe direction all call for the use of a label, as well as at any line entry or re-entry point. Another set of guidelines in the pipe marking standard is the size of the label and the height of the letters used; the bigger the diameter of the pipe, the bigger the label needs to be.

If you are looking to begin a pipe labeling project or update your current labeling efforts, ANSI/ASME A13.1 has all the information you need to create a system that works for your facility and will keep workers safe. Pipe markers are also essential for maintenance purposes and can be extremely beneficial for emergency responders. Take an audit of the pipes currently in your facility, and from there you can begin planning what types of labels you will need.

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