ANSI/ASME A13.1 Pipe Labeling Requirements

Pipe marking quickly communicates essential information to everyone in a facility, improving overall workplace safety and productivity. The American National Standards Institute (ANSI) offers a systematic approach for labeling the piping systems in a facility, in the ANSI/ASME A13.1 standard. ANSI recommendations for pipe marking are recognized and respected in most industries, and are an excellent starting point for most pipe marking projects.

History of ANSI/ASME A13.1

ANSI/ASME A13.1 is the broadest and most common recommendation for pipe marking in the United States. The standard has been revised over time, with the biggest change in 2007 when the old ANSI standard was combined with recommendations from the American Society of Mechanical Engineers (ASME). As a result of the cooperation between the two groups, the new standard has been called “ANSI/ASME A13.1,” or “ASME A13.1.”

The 2007 edition dramatically changed the color code to identify the type of hazard posed by a pipe’s contents, rather than only showing whether the contents were hazardous. Additional colors were specified for user definition, allowing flexibility for unique situations. The latest edition, which was in 2020, includes minor revisions. It kept the specialized color code, expanding one category to include abandoned pipes. ANSI A13.1 also has the option to include hazard pictograms from the international GHS standard on labels, for more detail.

When a pipe's contents or use could pose a hazard to workers, pipe marking may be a necessary step for workplace safety, and missing labels can put your facility at risk of citations under OSHA’s General Duty Clause. While OSHA requires certain industries to follow the ANSI pipe marking standard, other facilities are better served with a different system; consider the pipe marking standards that will apply to your facility’s type and location. Check with your local authorities before beginning a pipe marking project to ensure you’re fully complying with the law.

Pipe Label Requirements & Components

Under the ANSI/ASME approach to pipe marking, there are five key elements to an effective pipe label:

1. Bold text to identify the pipe’s contents by name. (Additional details, such as temperature or pressure, may also appear.)
2. Color coding to communicate the general category of the contents.
3. Flow direction arrows to show which direction the pipe’s contents flow.
4. Label sizing to ensure the label is visible and legible.
5. Label placement for clear viewing from a normal approach.

For additional details about these five elements, see our Best Practice Guide to Pipe Marking.

ANSI Pipe Marking Color Code

ANSI/ASME A13.1 recommends a color code designed to quickly alert workers to potential hazards. The color code consists of six predefined colors to identify broad types of pipe contents. There are also four user-defined combinations that can be defined separately by each facility using the standard.

The most hazardous feature of the pipe contents should determine the color scheme used:

Each category uses a solid color for the label background, which may also be used to color the entire pipe if desired. The text must appear in a contrasting color. If pipes fall under more than one category, there are two common approaches for choosing the color: identify one of the hazard types as more significant, and use that categorization, or use one of the user-defined colors to identify that particular type of pipe in the facility.

Clearly document the color code in use, and train workers to recognize and understand it. This is especially important in situations where a highly specialized piping system makes the common ANSI color code less effective. For example, pipes in hospitals often carry a variety of compressed gases; some are for patients to breathe, while others are for operating equipment, and others are part of an anesthetic system. Confusion across these types of pipes could be dangerous, or even fatal. As a result, hospitals typically follow a more specialized color code system.

Pipe Label Size

The diameter of the pipe will determine the appropriate label and text size. A size chart can help any facility understand the appropriate label for their specific piping system. Determine the label sizes you need for your pipes by identifying the outside pipe diameter.

Pipe Label Placement

Labels must always be clearly visible from the normal angle of approach. For example, if the pipe is overhead, apply the label below the centerline. If the pipe is below eye level, apply the label above the centerline. Additional recommendations for label placement:

• Near all valves and flanges.
• Adjacent to changes in direction.
• Both sides of floor/wall penetrations.
• At regular intervals on straight runs of pipe; at least one label every 50 feet (about 15 meters) throughout the piping run.

When applying a label directly to a pipe or covering is not possible, apply a valve tag or stand-off pipe marking sign blank—they’re both ideal for small pipes, providing a durable base for labels. If pipes are difficult to label or tend to get greasy and dirty, pipe grabber sleeves will protect labels and prevent damage. When you’re ready to install your labels and have pipes that are difficult to reach, a pipe marker applicator is a great way to safely and securely apply them without a ladder.

Pipe Marker Evaluation Checklist

When you’re ready to carry out a full pipe marking project, do a walk-through of your facility and take note of the labels that are needed. Streamline the process with a handy evaluation checklist. Periodically, repeat a general pipe marker inspection process to ensure labels are intact, legible, and accurate. Always replace any damaged, outdated, or worn labels right away to maintain safety and prevent new hazards.

Streamline Your Pipe Labeling Efforts

If you’re ready to install or update pipe marking for your entire facility, DuraLabel printers are a convenient and quick way to get started. In addition, you can produce labels and signs for a variety of other industry labeling requirements. Consider a pipe marking starter kit to ease the labeling process. It contains all the essential labeling supplies you’ll need at a discounted price.

For smaller jobs, premade pipe markers are perfect for one-off labels, replacement labels, and other small pipe labeling projects. These labels ship to your facility ready to install and are preprinted with all the essential information to make up a standardized pipe label in line with ANSI/ASME A13.1 and the International Institute of Ammonia Refrigeration (IIAR) pipe marking standards.

Already printing your own labels? Use our free Pipe Marking Chart below to ensure your pipe labels are clear and compliant.