Acetylene gas must be withdrawn from a cylinder at an hourly rate that does not exceed _________ percent of the cylinder capacity.

Acetylene gas is highly flammable and requires careful handling due to its instability under pressure and the potential for violent decomposition, especially when withdrawn too quickly from a cylinder. The correct withdrawal rate is important to ensure safe usage and to maintain the integrity of the gas in the cylinder.

Withdrawing acetylene at a rate that does not exceed 10 percent of the cylinder capacity per hour ensures that the pressure inside the cylinder remains stable and does not fall below a critical level that might compromise safety. By adhering to this guideline, operators minimize the risk of accidents such as flashbacks or explosions, which can occur if acetylene is drawn off too rapidly.

This withdrawal rate also enables the gas to remain in its dissolved state, preventing the formation of gas bubbles that could lead to unpredictable behavior and increased hazards during usage. Thus, maintaining the withdrawal limit at 10 percent is an essential safety measure in the handling of acetylene gas.