Cloud Point

The cloud point is a term primarily used in the context of petroleum and petroleum products, particularly in the field of fuel and lubricant chemistry. It refers to the temperature at which solid or semi-solid particles start to form and separate from the liquid phase of an oil or fuel when it is cooled.

In simpler terms, when you cool down a liquid like diesel fuel or motor oil, some of the components in the liquid may start to solidify or become cloudy. This clouding or solidification is known as the cloud point. The cloud point is an important property to consider, especially in colder climates, because it can impact the performance of these products. For example, if the cloud point of a diesel fuel is too high, it can lead to clogging of fuel filters and poor engine performance in cold weather.

To prevent issues related to clouding, fuel and lubricant manufacturers often formulate their products to have cloud points that are appropriate for the expected operating temperatures. Additionally, additives can be used to modify the cloud point and improve low-temperature performance.

It's worth noting that the cloud point is different from the pour point, which is the temperature at which a liquid becomes so viscous that it can no longer flow or be easily poured. Both the cloud point and pour point are important considerations when selecting and using petroleum-based products in various applications.