When you’re lining up plans for cold flow treatment of diesel fuel, there are two key variables you need to have a handle on. When can you expect to have to deal with the problem? And what’s it going to take to get your fuel where it needs to be with respect to gelling prevention?
To put it another way, cold weather treatment of diesel fuel relies on having the anti-gel treatment in the fuel before it starts the gelling process. This requires you to have some kind of idea of the temperature at which you can expect to have fuel gelling. In other words, you need to know what temperature your diesel fuel gels at, and you need to know how much cold flow improver you’ll need to use in order to get the level of protection your diesel fuel needs.
Knowing Your Fuel's Temperature
Professional fuel users have a good idea when they need to add cold flow improver because they generally know the cloud point and plug point temperatures of their fuel. And they keep track of outside temperatures so that they have an idea ahead of time when they need to break out the cold flow improver (since it needs to be in the fuel before the fuel gets too cold).
In general, satisfactory operation should be achieved in most cases if the blended fuel is 6 degrees C above the "10th percentile minimum ambient temperature" for the fuel's area. This term may not mean anything by itself, but it's supposed to be the temperature that isn't supposed to be below for more than 3 days out of a given 30 day period. This is different for different areas and different times of year. For example, Long Island's 10th percentiel temperature in December is -14 degrees C. For Alabama in December, it's -6 degrees C.
As a user, you want to start considering cold weather treatment when the temperature starts coming within 5 degrees of your fuel's cloud point. This means, if you're tracking the ambient temperatures for your area, when the forecast starts projecting lows that approach 10 degrees above the normal 10th percentiel minimum ambient temperature, that is the time for you to get your cold flow improver into the fuel.
Recently we did a video blog where we talked about these kind of issues that professionals are facing with respect to cold flow and prevention of diesel fuel gelling problems. If you missed it, feel free to have a look:
This post was published on September 1, 2016 and was updated on August 8, 2022.