Why pipes are painted different colors
Identification color is a safety measure: an installer, operator or firefighter understands in a second what medium is in the pipe and how dangerous it is. The rules for industrial pipelines in Russia and the CIS are set by GOST 14202.
The standard works on three levels: the color shows the substance group, warning rings show a special hazard, and marker plates and labels specify exactly what flows and where.
Identification colors by substance group
All substances are divided into 10 groups, each with its own color:
| Group | Substance | Color |
|---|---|---|
| 1 | Water | Green |
| 2 | Steam | Red |
| 3 | Air | Blue |
| 4, 5 | Flammable and non-flammable gases | Yellow |
| 6 | Acids | Orange |
| 7 | Alkalis | Violet |
| 8, 9 | Flammable and non-flammable liquids | Brown |
| 0 | Other substances | Grey |
That is why a gas pipe in a courtyard is yellow, boiler room pipes are green and red, and an oil pipeline is brown.
Warning rings
If a substance is particularly hazardous, colored rings are applied over the identification color:
| Ring color | Meaning |
|---|---|
| Red | Highly flammable, fire-hazardous and explosive substances |
| Yellow | Hazardous and harmful substances: poisonous, toxic, causing burns, as well as high pressure or deep vacuum |
| Green | Safe and neutral substances |
The number of rings shows the hazard level by pressure and temperature: the more rings, the more dangerous. Exact limits are in the GOST 14202 table for each substance group.
How the marking is applied
- Full painting — along the entire pipe length;
- Painting in sections — at the most visible and critical points: branches, valves and instruments, wall and floor penetrations, building entrances;
- Arrows show the flow direction;
- Marker plates state the medium, pressure and temperature.
On insulated pipes the color is applied to the jacketing — the metal cladding or protective sheath.
Common mistakes
- Painting the whole pipe in the ring color — a ring must differ from the base color, otherwise it cannot be seen.
- Forgetting flow direction arrows — the operator has to guess which line is supply and which is return.
- Not renewing the marking after repairs: the replaced section stays in grey primer.
- Using corporate colors instead of standard ones — outside personnel will not understand them in an emergency.
We supply pipes, elbows, flanges and valves for your pipeline.
Equipment catalogueFAQ
What color is a gas pipe?
What color are heating pipes?
Must the whole pipe be painted?
What do red rings on a yellow pipe mean?
How is an insulated pipe marked?
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