Pipe Color Code Chart and Standards

Pipe markings save lives. Pipes are used in facilities to transport liquids and gasses from one place to another, both short and long distances. Most facilities have dozens of pipes moving different things around the facility, so it is important to be able to keep track of what is in each pipe and where it is going. This is where pipe color code chart and standards can become essential.

If pipe color codes are not used, it can be difficult to know what is within a given pipe, which can present many dangers. If someone opens a pipe that is not marked with the proper colors, he or she may expect clean water but get a toxic chemical.

Pipe color-coding is not a complicated process, especially if industry standards are used. There are many standards out there from a variety of sources, but the most popular is the ANSI/ASME A13.1 standard. This standard explains colors, text, size, and placement of pipe marking labels.

Following this type of color-coding standard makes it easy to offer training to employees and also helps ensure different departments within a facility are all using the same colors for their pipes.

  1. ASME/ANSI A13.1 – Scheme for the Identification of Piping Systems
  2. BS 1710 – Specification for Identification of Pipelines and Services
  3. IS 2379 – Pipelines Identification Color Code
  4. PFI ES-22 – Recommended Practice for Color Coding of Piping Materials
  5. OSHA (Occupational Safety and Health Administration)
  6. NFPA (National Fire Protection Association)
  7. ISO 14726 two-color band system (main vs. secondary colors)

ANSI/ASME A13.1 Pipe Color Code Standards Explained:-

Businesses should familiarize themselves with the ANSI/ASME A13.1 pipe color code standard, which is the industry consensus standard for marking pipes. This standard identifies the color of the labels and what those colors mean. The following are the main options for this set of standards:

  • Yellow with Black Lettering – This option is used for any pipe that contains flammable liquids and gasses. This could include gasoline, oils, and many others.
  • Green with White Lettering – Using a green label with white lettering means that the pipe contains potable water. It could be used for cooling, feeding boilers, or even going to drinking fountains or sinks.
  • Blue with White Lettering – The blue labels with white lettering are used for pipes that transport compressed air.
  • Red with White Lettering – This red label with white lettering is used for all fire quenching fluids. This could include water, but only if the pipe is used just for fire quenching.
  • Orange with Black Lettering – Orange labels with black lettering are for toxic or corrosive fluids. Most acids will need to use this type of pipe marking.
  • Brown with White Lettering – This option is for all combustible fluids.
  • Note: Any product manufactured by welding shall have an additional white stripe.

The ANSI/ASME color codes for pipes also leave several color combinations for “user defined” pipes. This is important because it allows facilities to plan out certain pipes that don’t fit in with the normal standards. It is important to remember, however, that whenever using user-defined pipe markings, people who haven’t been sufficiently trained won’t know what they mean.

The user defined color options are:

  • Purple with White Lettering
  • White with Black Lettering
  • Gray with White Lettering
  • Black with White Lettering

The below figure shows the latest pipe color guidelines set by ANSI/ASME.

Piping Color Guidelines Set by ANSI,ASME

Piping Color Guidelines Set by ANSI,ASME [Source: From Web]

Other than color code, additional information regarding the nature of the contents of the pipe by using the following systems either individually or in combination:

  • Name in full
  • Abbreviation of name
  • Chemical symbol and
  • Appropriate code indications or code color bands

When using pipe markings, a facility must choose to either buy generic pipe markings, special order custom pipe markings, or obtain blank pipe markings that can be printed on using an industrial label maker. Each of these options can be effective. For facilities that have lots of pipes, the label maker is going to be the ideal option. For those who need just a few labels, special ordering is likely the best choice.

Pipe Marking Size Requirements

The color of pipe markings is typically the most important and visible aspect of the label, but it is not the only one. ANSI also has standards regarding how large a pipe marking label should be and the size of the lettering on the label. This is especially important when creating custom labels for a facility. The standards for sizing are as follows:

Pipe Diameter Pipe Marking Size
¾ – 1 ¼ should have pipe markings that are at least 8 inches in length and lettering that is at least™ in ½ height
1 ½ – 2″ should have 8″-long pipe markings with ¾ letter height
2 ½ – 6″ should have labels that are 12″ in length with lettering that is 1 ¼ in height
8 – 10″ should have 24″-long pipe markings with 2″ letter height
Greater than 10″ should have labels 32″ long with lettering 3″ in height

These standards are important, as they will help ensure that the pipe markings are as visible as possible, even from a distance.

It is very important that Pipe Labels are properly cared for once they are placed on the pipes. In industrial facilities, pipe markings can get covered in dust, grease, and other contaminants over time, especially if pipes are located in out-of-reach areas such as near the ceiling. Having pipes cleaned on a regular basis will make labels easy to see. Even having a layer of dust on a label can cause the color to appear different than it is. This could cause someone to incorrectly assume they know what is in a given pipe, which opens them and the facility up to the potential for dangerous accidents.

Fortunately, pipe marking labels are typically made to stand up to any cleaning, so they will last for a long time with proper care. When facilities take the time to dust or wash the pipe markings at least a few times per year, it is easy to avoid any trouble associated with dirty labels.

Latest 2025 Pipe Marking & Labeling Updates to Consider

The following considerations will help ensure pipe labels are visible to the people who need to see them:

  1. The Frequency of Labels – Labels need to be placed at least every 25-50′ on the pipe so they are easy to see. It is also important to add a label if the pipe changes direction so that it is clearly visible.
  2. Obstructions to the Label – If a pipe goes through a wall or around a corner, labels should be placed on either side so that people can see the color of the label from any angle.
  3. Lighting – While pipes are often in areas that don’t get too much light such as under the floors or in the rafters, it is helpful to ensure a sufficient amount of light is reaching them so people can see the colors and words on the labels. New practices emphasize larger fonts, simplified text, and high-contrast designs for quick recognition, even in low-light conditions.
  4. Near Access Points – If there are designated access points to a pipe, it is important to have a label visible. This will help the maintenance team quickly determine what is in a pipe before working on it.
  5. Near End Points – At either end of the pipe, there should be a label so that people using the pipes can quickly see what is in them.
  6. Stronger Hazard Identification: There is an increased focus on highlighting flammable, toxic, corrosive, or high-pressure pipelines to meet updated safety and compliance requirements.
  7. Standardized Arrow Placement: For better visibility, flow arrows are now recommended on both sides of the label text, ensuring the direction of flow is clear from any angle.

Comparison Of Pipe Color Code Standards Table:

Standard Region Code Type Color Meaning Examples
ANSI/ASME A13.1 USA Background + Text Yellow/black = flammable; Red/white = fire fluid
IS 2379 India Ground + Band Sea green = water; Light brown = oil; etc.
BS 1710 UK Base + Safety band Green = water, red band = firefighting
ISO 14726/20560 Marine/Intl. Dual-colored bands Black = waste; Silver = steam, etc.
PFI ES-22 USA (fabrication) User-defined options Custom colors with added white stripe for welded pipes

Frequently Asked Questions (FAQs) on Pipe Color Codes & Labelling

Q1: What are pipe color codes?
Pipe color codes are standardized colors applied to pipelines to identify the type of material being transported—such as water, steam, oil, gas, or hazardous chemicals. These codes follow international standards like ANSI/ASME A13.1, IS 2379, BS 1710, and ISO 14726 to improve workplace safety and reduce accidents.

Q2: Why is pipe labeling important?
Pipe labeling ensures that workers and inspectors can quickly recognize the contents and flow direction of a pipeline. This prevents accidents, improves maintenance efficiency, and helps industries stay compliant with safety regulations.

Q3: Which standard governs pipe labeling and color codes?
The most widely recognized standard is ANSI/ASME A13.1 (USA). However, different regions follow additional standards like IS 2379 (India), BS 1710 (UK), and ISO 14726 (marine and international use).

Q4: What information should a pipe label include?
A compliant pipe label typically shows:

  • The pipe contents (e.g., water, natural gas, steam)
  • The direction of flow using arrows
  • A color code specific to the substance category
  • A readable font size appropriate for the viewing distance

Q5: What are the 2025 updates in pipe marking practices?
Recent updates place more emphasis on visual clarity, hazard identification, and standardized arrow placement. Larger fonts, simplified text, and better hazard markings are being adopted globally to improve safety and compliance.

Q6: What are the common pipe marking mistakes to avoid?

The common pipe marking mistakes to avoid are as follows:

  • Missing Arrows: Flow direction is critical for emergency responders.
  • Wrong Colors: Using the wrong background color can cause confusion.
  • Small Text Size: Labels unreadable from a distance defeat their purpose.
  • Poor Adhesion: Low-quality labels peel off quickly, especially in harsh conditions.

Established in 1975, the Metallica Metals Group has its operations spread across major cities in India. We are a pioneer in the seamless as well as welded stainless steel pipes, carbon steel pipes, alloy steel pipes, stainless steel pipe fittings, carbon steel pipe fittings and alloy steel pipe fittings, with flanges manufacturing and processing industry. Our products are exported to over 70 countries across the world, while in India we have supplies to even the remote areas. With over 250 tons of sale in stainless steel and carbon steel pipes every day, Metallica has emerged as a prominent vendor for many buyers in India and Overseas.