Why must acetylene cylinders be stored vertically?

Acetylene cylinders are designed to be stored vertically primarily to prevent acetone from being drawn off. Acetylene is dissolved in acetone inside the cylinder under high pressure, which allows it to be stored safely. If the cylinder is stored horizontally or at an angle, there is a risk that acetone, which is a liquid, might flow out with the gas during use. This could lead to improper operation of the gas cutting or welding equipment, potential safety hazards, and inefficient gas use.

Maintaining the cylinder in a vertical position ensures that only the gas phase is released from the top, preserving the integrity and effectiveness of the acetylene as a fuel gas. This design feature is crucial for safe operation in any welding or cutting tasks.