Question

In oxy-acetylene gas welding equipment, the outside surface of oxygen cylinder is usually painted with colour.

• A. Red
• B. Black
• C. Maroon
• D. Yellow

Hint:

A simple way to remember: Oxygen = Black (Out in the Black of space). Acetylene = Maroon (Almost Maroon like a fire).

Answer 1

The Correct Option is B

In industrial safety and gas handling, cylinders are color-coded to prevent the dangerous mixing of gases. In oxy-acetylene welding, two different gases are used, and each has a standardized cylinder color code to ensure they are easily identifiable even from a distance. 1. Oxygen Cylinder Identification: The cylinder containing compressed

oxygen is traditionally and internationally painted

Black. Oxygen is a non-flammable gas but is a strong oxidant that supports combustion. It is stored at very high pressures (approx 150 bar).

2. Acetylene Cylinder Identification: The cylinder containing

acetylene gas (the fuel gas) is painted

Maroon (or sometimes Red depending on local standards, though Maroon is the standard industrial code). Acetylene is highly flammable and is stored dissolved in acetone within a porous mass to keep it stable.

3. Why Color Coding Matters: Mixing these up could be fatal. For example:

• Oxygen cylinders have right-hand threads, while fuel gas cylinders like acetylene have left-hand threads (often marked with a notch on the nut).

• The color code provides an immediate visual check before a welder even touches the valves or regulators.
Therefore, for the safety and standardization of the workshop, oxygen cylinders are always associated with the color black.