2020 ANSI/ASME Pipe Marker Guidelines

Did you know that the standards for pipe labeling have changed? The most current standard is the ASME A13.1-2020: Scheme for the Identification of Piping Systems and it was released in late 2020. The standard establishes six requirements for the proper identification of piping systems: Marker size, letter height, color, legend (wording), directional arrow, and placement.

Comparing the new A13.1-2020 standard and the previous standard (A13.1-2015)

• The most recent 2020 update includes new pipe diameter and letter height requirements. - See Table 1
• A13.1-2020 now includes a guideline for marking abandoned pipes. - See here
• A13.1-2020 continues the 2015 addition of the optional GHS (Global Harmonized System) pictograms. - See Table 4

HOW ARE MARKER SIZE AND LETTER HEIGHT DETERMINED?

The marker size and letter height are determined by the overall pipe diameter, including insulation. Marker length or color field requirements can be met by including an arrow or arrow banding tape. Letter height requirements are designed for optimum visibility on a pipe and adequate viewing distance. See Table 1 – Marker and Letter Size References.

TABLE 1: Marker and Letter Size References

WHAT DO THE COLORS SIGNIFY?

Marker colors are for more than just looks. The colors help to easily identify the inherent danger of the piping contents. There are eleven color designations, seven standard and four user defined. See Table 2 – “Color Designations”.

Table 2: Color Designations

HOW IS THE LEGEND DETERMINED?

The wording can be the full or abbreviated name of the system content. The standard indicates “Legends shall be brief, informative, pointed, and simple for greatest effectiveness.” The legend should have “sufficient additional details such as temperature, pressure, etc., as are necessary to identify the hazard.” - click here for standard legends list.

WHY USE DIRECTIONAL ARROWS?

Arrows are used to show the directional flow of the piping contents. If flow can be in both directions, arrows in both directions should be used. (Kolbi’s Wrap-Around Markers include arrows. Adhesive Markers comply when used with Arrow Banding Tape or Individual Arrows)

WHERE DO THE MARKERS GO?

Marker placement is required to assure visibility and should be positioned so that they are visible to personnel from a normal point of approach. Where pipes are located above or below the normal line of vision, the lettering should be placed above or below the horizontal centerline of the pipe. See Table 3 – “Location of Identification Markers”.

Table 3: Location of Identification Markers

DO I USE GHS PICTOGRAMS?

The use of GHS pictograms or symbols is optional. Where piping is connected to containers labeled in accordance with GHS requirements, a corresponding label which includes pictograms may be provided. See Table 4 - Standard GHS Pictograms.

Table 4: GHS Pictograms

WHAT ABOUT MARKING ABANDONED PIPING?

The new 2020 standard recommends marking abandoned piping left in place. These should be marked with a safety white marker with black letters and include a black border. If the piping is protected by pressurized fluid or contains residual hazardous materials, the legend should indicate that.