Color coding of pipelines and piping materials are standard industry practices.  Color marking will make identification easier for raw material and fluid that is being transported by the pipe. There are various national and international Pipe Color Code Standards available. (I have used both British and American versions to spell color/colour)

  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 Colour Code
  4. PFI ES-22 – Recommended Practice for Color Coding of Piping Materials

Color Coding of Piping Material – PFI ES-22

Why the color coding of piping material?

Various grades of carbon steel, alloy steel, and stainless steel are used during construction and fabrication. To avoid mixing of this material and easy storing and retrieving in the warehouse, piping components such as pipe, fittings, flanges, and valves are color coded.

Most companies have their own color coding system. Pipe Fabrication Institute (PFI) Standard ES-22 provides Piping Materials color coding requirements for the most commonly used piping material grades. It also provides guidance on marking location of piping components.

Refer to below images for the color band location on piping components.

flange marking and color coding
Tee color marking
ss elbow marking
Elbow color code
reducer color coding
ss pipe reducer color code
SS Pipe Color Code standard

Color Code for Pipe Material Identification – PFI Standard ES-22 -1999

Carbon Steel Material

Carbon Steel
MaterialMaterial GardeBand / Strip Color
Carbon Steel, Electric Resistance Welded   PipeA53 Gr. B/API1 solid white
Carbon Steel, Smls, specified tensile   strength under 70,000 psi (483 MPA)A53 Gr. BNo Marking
Carbon Steel, killed steelA106 Gr. B1 solid green
Carbon Steel, specified tensile strength   70,000 psi (483 MPA) and overA106 Gr. C2 solid green
Carbon Steel, low temperature (impact   tested)A333 Gr. 61 solid red

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High Yield Carbon Steel

High Yield Carbon Steel
MaterialMaterial GardeBand / Strip Color
52,000 min. yieldAPI 5L X-521 solid yellow, 1 solid green
60,000 min. yieldAPI 5L X-601 solid yellow, 1 solid pink
65,000 min. yieldAPI 5L X-652 solid yellow
70,000 min. yieldAPI 5L X-701 solid yellow, 1 solid orange

Low Alloy Materials

Low Alloy Materials
MaterialMaterial GardeBand / Strip Color
C-Mo steelA335 Gr. P11 solid orange
1 Cr-1/2 Mo SteelA335 Gr. P121 solid orange, 1 solid blue
1 1 /4 Cr-1/2 Mo SteelA335 Gr. P111 solid yellow
2 1/4 Cr-1 Mo SteelA335 Gr. P221 solid blue
5 Cr-1/2 Mo SteelA335 Gr. P51 solid blue, 1 solid yellow
9 Cr-1/2 Mo SteelA335 Gr. P92 solid orange

Ferritic and Martensitic Stainless Steels

Ferritic and Martensitic Stainless Steels
MaterialMaterial GardeBand / Strip Color
Type 405A268 TP4051 solid green, 1 solid black
Type 410A268 TP4101 solid green, 1 solid red

Austenitic Stainless Steels

Austenitic Stainless Steels
MaterialMaterial GardeBand / Strip Color
Type 304A312 TP3041 solid black
Type 304LA312 TP304L2 solid black
Type 304HA312 TP304H1 intermittent black
Type 309A358 Gr3091 solid black, 1 solid brown
Type 310A358Gr3101 solid green, 1 solid orange
Type 316A312 TP3161 solid gray
Type 316LA312 TP316L2 solid gray
Type 316HA312 TP316H1 intermittent gray
Type 317A312 TP3171 solid brown, 1 solid green
Type317LA312 TP317L1 solid brown, 1 solid red
Type 321A312 TP3211 solid pink
Type 321 HA312 TP321H2 solid pink
Type 347A312 TP3471 solid brown
Type 347HA312 TP347H2 solid brown

Nickel Based Alloys

Nickel Based Alloys
MaterialBand / Strip Color
Nickel 2001 solid black, 1 solid pink
Incoloy 8001 solid black, 1 solid orange
Incoloy 800H1 solid gray, 1 solid red
Incoloy 8251 solid gray, 1 solid blue
Inconel 6002 solid blue
Inconel 6251 solid blue, 1 solid pink
Hastelloy Alloy 8-21 solid red, 1 solid orange
Hastelloy Alloy C-2761 solid red, 1 solid blue
Hastelloy Alloy C-222 solid red
Hastelloy Alloy G1 solid red, 1 solid yellow
Carpenter Alloy 20 C 8-31 solid black, 1 solid blue
Monel 4001 solid black, 1 solid yellow

Color Coding of Pipeline and Piping Identification

Oil and Gas Industries, Process industries are complex installations. Piping systems are used in these plants to transport various fluids. These pipelines transport various industrial materials such as gases such as Air, Nitrogen, Oxygen, Hydrogen, etc., liquids such as water, acids, hydrocarbon, toxic materials, etc.

Identifying the material pipeline transporting without a proper pipe color code is extremely difficult. Systematic color coding of pipelines and piping systems is essential to reduce the safety hazard and the possibility of mistakes in identification and accidents associated with the wrong identification of pipelines during an emergency situation. Uniformity of color marking promotes greater safety, lessens the chances of error, and reduces hazards in handling material inside the pipelines.

National and international standards provide the guidelines for uniform color coding in industries that are used to color code of pipes to identify.

  • ASME A13.1 – Scheme for the Identification of Piping Systems
  • BS 1710 – Specification for Identification of Pipelines and Services
  • IS 2379 – Pipelines Identification Colour Code

These standard uses different color code methodology to identify the pipe material. They use a base color, band color, letters, and direction arrow to identify fluid inside the pipeline.

ANSI/ASME A13.1 – Scheme for the Identification of Piping Systems

The purpose of the ASME/ANSI A13.1 Standard is to establish a common system that assists in the identification of hazardous materials conveyed in piping systems and their hazards when released into the environment.

ASME A13.1 – 2015 edition has six fixed colors, and four users define colors that can be used to identify hazardous material. In this standard, the following categories are used;

  1. Flammable – Fluids or vapor or produce vapors that can be ignited and continue to burn in air.
  2. Combustible – Fluids that can burn, but are not flammable.
  3. Oxidizing – Oxidizing fluid is any gas or liquid that may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does.
  4. Toxic and Corrosive – Fluids that are corrosive or toxic, or will produce corrosive or toxic substances when released.
  5. Fire Quenching – Fluid Such as water, foam, and CO2 used in sprinkler systems and firefighting piping systems.
ASME A13.1 Pipe Color Code Chart

Size of Label and Letters as per ASME B13.1-2015

ASME A13.1 Lable Dimesion
Outside Diameter of Pipe in InchesOutside Diameter of Pipe in mmLength of Color Field, A, in InchesLength of Color Field, A, in mmSize of Letters, B, in InchesSize of Letters, B, in mm
3⁄4 to 11⁄419 to 3282001⁄213
11⁄2 to 238 to 5182003⁄419
21⁄2 to 664 to 1501230011⁄432
8 to 10200 to 2502460021⁄264
Over 10over 2503280031⁄289

BS 1710 – Specification for Identification of Pipelines and Services

BS1710 uses two types of colour coding to identify the content of pipe and hazard.

  1. Base colour – Base colours are used to indicate the content inside the pipe.
  2. Safety colours – These colours are used as band colours that applied in conjunction with the base pipe color code to create various service identifiers.

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

  1. Name in full
  2. Abbreviation of name
  3. Chemical symbol and
  4. Appropriate code indications or code colour bands
BS1710 pipeline colore code standard

Size of Label as per BS 1710 -2014

  1. When Only Basic Identification Color Used
BS1710 lable size
Pipe DiameterMinimum Band Width
Up to 50 mm130 mm
50 mm to 100 mm275 mm
above 100 mm450 mm

2. Basic identification colour with code and/or safety colours

BS1710 lable size with color band
Pipe DiameterMinimum Band Width – Basic Colour (1)Minimum Band Width – Safety Colour (2)
Up to 50 mm50 mm30 mm
50 mm to 100 mm100 mm75 mm
above 100 mm150 mm150 mm

IS 2379 – Pipelines Identification Colour Code

IS 2379 is Indian Standard for the colour coding requirements. It is quite comprehensive and a little complex as compared to BS and ASME standards. IS 2379 is more in line with BS 1710. It used the ground colour, band colour, and letter labeling to identify fluid content and associated hazards.

This standard covers piping systems that include pipes of any kind and in addition fittings, valves, and pipe coverings. Supports, brackets, or other accessories are excluded from this standard. This standard is not applicable to pipelines buried underground or used for electrical services.

Refer to the table for the ground colour that used in pipeline marking.

Ground Colours
WaterSea green
SteamAluminium to IS 2339
Mineral, vegetable, and animal oils, combustible liquidsLight brown
AcidsDark violet
AirSky blue
GasesCanary yellow
AlkaliesSmoke grey
Other liquids/gases which do not need identificationBlack
Hydrocarbons/organic compoundsDark admirality grey

Size of Label and Letters as per IS 2379 – 1990 (Reaffirmed 2006)

IS 2379 Lable size
IS 2379 pipe colour code
Length of the Colour Band
Nominal Pipe Size (mm)Ground ColourFirst Colour Band (mm)Second Colour Band
80 NB and belowThroughout the entire length or Band no case less than 300 mm254:1 Proportion to the First Colour Band
Letter Size
Outside Diameter of Pipe (mm)Size of Legend (mm)
20 to 3010
Above 30 to 5020
Above 50 to 8030
Above 80 to 15040
Above 150 to 25090
Over 25090

Commonly used Pipe Color Code As per Is 2379

Pipe Colour Code Use in Refinery As per IS 2379
ContentsGround ColourFirst Colour BandSecond Colour Band
Cooling WaterSea greenFrench blue
Boiler feed waterSea greenGulf red
Drinking waterSea greenFrench blueSignal red
Plant airSky blueSilver grey
Very high pressure steamAluminium to IS 2339Signal red
High pressure steamAluminium to IS 2339French blue
Medium pressure steamAluminium to IS 2339Gulf red
Low pressure steamAluminium to IS 2339Canary yellow
Light diesel fuelLight brownBrilliant green
Lubricating oilLight brownLight grey
Flare gasesCanary yellow
NitrogenCanary yellowBlack
OxygenCanary yellowWhite
HydrogenCanary yellowSignal redFrench blue
NapthaDark Admirality greyLight brownBlack
LPG (Liquid)Dark Admirality greyBrilliant greenDark violet

Location of the color band and Labels

Coloring and identification labels on the pipe should apply in such a way that is clearly visible from all the approaches, especially when pipes are overhead. ASME B13.1 and IS 2379 provide guidance on the positions of the labeling.  Refer to the table below for the general guideline provided in the standards.

Location of the Colour Band
As Per IS -2379AS Per BS 1710 & ASME B13.1
At battery limit pointsClose to valves or flanges
Intersection points and change of direction points in piping waysAdjacent to changes in direction, branches
Other points such as midway of each piping way, near valves, junction joints of service appliances, walls, on either side of pipe culvertswhere pipes pass through walls or floors
For long stretch yard piping at 50 m intervalat intervals on straight pipe runs sufficient for identification
At start and terminating points
Pipe Color Code Position

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