What could cause a pressure vessel burst as a result of igniting flammable vapor within it?

In the context of a pressure vessel, a deflagration refers to a rapid but sub-sonic combustion process that occurs when flammable vapors ignite. This type of reaction generates a significant amount of heat and gas expansion, which can lead to an increase in pressure within the vessel. If this pressure exceeds the design limits of the vessel, it could result in a catastrophic failure, such as a burst.

The process of deflagration can become critical in confined spaces like a pressure vessel, where the rapid expansion of gases can lead to shock waves and extreme pressure fluctuations. Ensuring proper venting or managing the conditions of flammable vapors is vital to prevent such an incident. Understanding this risk is a key component of safety management in industries dealing with flammable materials.

Other factors mentioned, such as cooling, decreasing pressure, or increasing oxygen concentration, do not directly lead to a burst caused by igniting flammable vapor in the same way. Cooling tends to reduce pressure and prevent combustion, while decreasing pressure typically mitigates the risk of a burst. Increasing oxygen concentration can enhance combustion but would not directly cause a vessel to burst without the presence of ignitable vapor and the specific conditions for deflagration to occur.