NR-26 Pipe Color Coding
Returns the standardized pipe color for water, steam, oil, air, or gas per Brazilian NR-26.
—
NR-26 & ABNT NBR 6493: piping color identification
Brazilian regulation NR-26 (Safety Signaling) works alongside the technical standard ABNT NBR 6493 to pin a base color on each fluid running through industrial piping. The point is that a worker or an emergency team can read what's inside a pipe without opening anything. The core palette goes like this: red marks fire-fighting water or foam, yellow (sometimes yellow-ochre) flags combustible gases, green covers cold industrial water, black is sewage and effluents, orange signals acids, violet is for alkalis, white means steam, and grey is reserved for vacuum lines.
You can paint the whole pipe or just apply bands. Band width follows the rule w ≈ D, scaling with the pipe's outside diameter D, and you repeat it near valves, branches, walls, and every 10–20 m along long straight runs. Arrows show which way the fluid moves. When two substances would otherwise share the same hue, the fluid name and pressure have to be written next to the color so nobody confuses them.
Applications
Refineries, chemical plants, food and beverage facilities, hospitals, water-treatment stations, HVAC plant rooms — they all lean on the code for day-to-day operation, lockout-tagout, hot work, and emergency response. A maintenance crew reads the bands to figure out what to isolate. Firefighters follow the red lines straight to hydrants and sprinkler risers.
FAQ
Is NR-26 color coding mandatory? Yes. The Ministry of Labour enforces NR-26, and if you don't comply you risk fines and even having the plant shut down.
What about gases like oxygen or nitrogen? NBR 6493 sets aside specific shades for them — light blue for oxygen, grey for nitrogen — backed by a written legend. Check the current revision of the standard before you commit, since the shades can change.
How often should the painting be renewed? Once the color fades to the point someone could misread it. Indoors that's usually every 3–5 years; outdoors, or anywhere chemically aggressive, expect to repaint sooner.
Related Tools
PVC Glue Pipe Joints
Estimates PVC glue ml for plumbing pipe joints.
Corrosion Thickness Loss
Calculate the cumulative thickness lost to corrosion, δ = CR × t, multiplying the corrosion rate CR (mm/year) by the service time t (years). The result, in mm, is the depth of material consumed over the period — direct input to assess the integrity of piping, tanks and structures and to decide on inspection, repair or replacement. Compared with the corrosion allowance set in design, it shows how much of the margin is already used and estimates the component's remaining life. Enter the corrosion rate and the service time.
Resistor Color Code Calculator
Decode 4, 5 or 6 band resistors from their colors and see the value in ohms with tolerance. Also supports the reverse (value → colors). Useful for electronics. Everything in your browser.
Pipe Expansion Leg (Guided Cantilever)
Computes the minimum free leg length a pipe run needs in order to absorb a thermal expansion without exceeding the allowable stress, using the guided-cantilever method: L = √(3 × E × D × Δ ÷ S_a). The idea is to treat the perpendicular leg as a fixed-end beam with a guided tip that displaces Δ along the direction of expansion; the resulting bending stress falls with the square of the length, so doubling the leg divides the stress by four. The method is conservative and is meant for sizing expansion loops and direction changes ahead of a formal flexibility analysis: the larger the outside diameter, the farther the outer fibre sits from the neutral axis and the more stress the same curvature produces, so the longer the leg needed for the same expansion — stiffness does not enter, and two pipes of equal outside diameter but different wall thickness need the same leg. Enter the modulus of elasticity, the outside diameter, the expansion to be absorbed and the allowable stress.
Standard Resistor Value (E6 to E192 Series)
Find the resistor value that actually exists in the E6, E12, E24, E48, E96 or E192 series, the error against your calculated value, and the matching colour code.
Holi Festival Date
Shows the approximate Holi (Hindu colors festival) date for upcoming years.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.