Final answer:
High pressure cylinders for acetylene must be handled with care, especially concerning temperature exposures that can raise internal pressure to dangerous levels. Acetylene tanks must be used with the correct amount of oxygen for safe combustion. Cooling may be used as a safety measure for cylinders with leaks, but practicality and safety must be considered.
Step-by-step explanation:
High pressure cylinders used to transport and store acetylene must adhere to strict safety standards due to the nature of compressed gases and the risks associated with them. Acetylene, which is used in applications such as welding, is stored at high pressure but can become dangerous when exposed to heat, as it may lead to a rise in the internal pressure of the cylinder. For example, if a cylinder containing gas at a pressure of about 200 atmospheres is exposed to a fire, the increase in temperature can cause the pressure within to rise, potentially reaching a point of failure if it exceeds the safety factor limit of around 400 atmospheres.
In practical applications, caution must be taken. For instance, acetylene tanks used in oxyacetylene welding torches contain a large volume of acetylene gas, which requires a specific amount of oxygen to burn correctly. The chemical reaction for burning acetylene, 2 C₂H₂ + 5 O₂ → 4 CO₂ + 2 H₂O, dictates the stoichiometry for how many tanks of oxygen will be needed for the combustion process.
For safety purposes, if a high-pressure cylinder leaks or is exposed to conditions that can compromise its integrity, such as a sudden increase in temperature, measures such as cooling can be taken. This approach is illustrated by a scenario where a cylinder containing toxic gas is cooled to a temperature of -78.5°C to reduce its internal pressure to a level where it can be safely repaired. However, considerations must be made to ensure that the temperature reduction is practical and does not lead to other risks or complications.
Overall, handling and storage conditions for high-pressure acetylene cylinders must be carefully managed. They require consistent monitoring and regulation to ensure safety, particularly in relation to temperature controls to prevent dangerous pressure increases.