Pipe marking is obligatory for all pipes containing dangerous substances.
EU regulation no. 92/58 among others states that:
Containers used while working with dangerous substances or preparatives that are defined in 67/548/EHS regulation, containers used for storing these dangerous substances or preparatives and visible pipeline containing or conveying dangerous substances or preparatives must be marked with a label (pictogram or symbol on colourful background) in accordance with this regulation. Substances that are defined by 67/548/EHS regulation are all that are specified as: explosive, oxidising, highly flammable, toxic, injurious to health, corrosive and irritant.
How to mark pipes?
In the Czech Republic the procedure of marking the pipes is defined by ČSN 13 0072 norm, which inter alia states:
- The surface of pipes designed for fire prevention is covered with a red coat or marked with black strips in a colour according to ČSN 01 8010.
- Pipes with compressive drinking water are marked with a strip in blue colour according to ČSN 01 8010.
- In the operations, there must be marking which is clear and visible from the local service of the equipment, armature and others.
- According to the operational liquid the pipes are marked with self-adhesive strip at least 150 mm wide of colour according to a chart of colours.
- Pipes that are situated 150 – 500 mm from some machinery, pipes crossing, pipes bridges, armatures and front and behind obstacles or walls, which the pipeline passes, are marked with strips and belts on principle. The straight pipes are marked on necessary places or regularly in 5 to 10 m distances.
- Coloured pipe marking is complemented with headings, labels and safety signs according to Part IV of the relevant norm.
Coloured pipe marking can be complemented with labels and signs which state:
- A title of operational liquid, for example boiler feed water
- Marking of letters and figures combinations, for example NaOH 30%
- Chemical formulas of the operational liquid, for example H2O
- It is recommended to indicate the direction of flow of the working fluid by an arrow
- The dangerousness of the operational liquid is in the operations usually marked on the pipes with ČSN 01 8012 signs, which complement the previous data. A safety sign can be a part of a label or a chart.