What is the lowest temperature at which fuel oil will flow known as?

The lowest temperature at which fuel oil will flow is known as the pour point. This term is significant in understanding the behavior of fuel oil under varying temperature conditions. Specifically, the pour point is the temperature below which oil becomes too viscous to pour or to flow adequately. It is crucial for boiler operators to know this temperature to ensure proper handling, storage, and usage of fuel oil, especially in cold weather conditions where the risk of clogging increases.

Recognizing the pour point allows operators to maintain system efficiency and prevent operational issues related to fuel delivery. In contrast, the flash point refers to the lowest temperature at which the vapors of a substance can ignite in air, which is important for safety but does not relate to the flow characteristics of a liquid. The melting point pertains to the transition from solid to liquid state, which is not applicable to oils in these contexts, while the vapor point relates to the temperature at which a liquid turns to vapor, which also does not address flow characteristics. Therefore, pour point is the appropriate term for this aspect of fuel oil properties.