Fuel contains paraffin wax in two forms, liquid wax that is in suspension in the
fuel and wax seed crystals that are floating throughout the fuel. In
temperatures above the fuels Cloud Point (CP) you can't see wax without a
microscope. When fuel reaches its Cloud Point wax in the fuel has begun
attaching itself to the wax crystals making them large enough to be seen with
the naked eye. This wax will appear as a cloud-like formation floating in the
fuel temperature drops the wax crystals continue to get larger and will begin to
stick to each other. At this Cold Filter Plug Point (CFPP) or Gel Point the fuel
will have difficulty passing through fuel filters. This is the critical point at
which it can become difficult or impossible to operate an engine or burner.
temperature continues to drop the fuel can become a semi-solid, this is known as
the Pour Point (PP), or the point at which fuel will no longer pour.
prevent from fuel from gelling in three ways.
fuel temperature above the CFPP or Gel Point,
with a fuel such as kerosene that has less wax to spread out the wax and wax
Cold Flow Improver or Anti-Gel to prevent the wax crystals from growing and
the wax crystals from sticking together
can be difficult if not impossible, number two can be very expensive and with
the New Ultra Low Sulfur Diesel is no longer reliable; it can require so much of
a special Ultra Low Sulfur Kerosene as to be impractical. Number three can be
done reliably and inexpensively and is the best way to deal with these issues.
Improvers or Anti-gel are a co-polymer that coats the paraffin wax crystals
normally found in all diesel fuels to prevent the wax crystals from getting any
larger and to prevent them from sticking to each other (gelling).
anti-gel material is quite thick and must be blended with solvents to allow it
to be mixed properly with fuels. It is important to understand that even
anti-gels blended with solvents will thicken at temperatures below 40°F. Fuel
additives containing anti-gel should be stored above 40°F. If stored below 40°F
allow them to warm up before adding them to the fuel.
of what happens to anti-gel is what happens with coolant antifreeze. By itself,
antifreeze will thicken in cold weather to the point of being nearly solid, but
when mixed with the correct amount of water it will prevent freezing to -40°F or
work in a similar way, when mixed with the correct amount of fuel they
effectively prevent gelling, lowering the gel point by as much as 35°F.
important thing to remember about anti-gel additives is that you have to treat
the fuel before it begins to gel. Products such as Complete Fuel Treatment™
are preventatives designed to prevent gelling, once the fuel has gelled
anti-gels won’t help you until the fuel has thawed.
tells you they have an anti-gel additive that does not thicken when cold you
should know and understand that there are two types of additives that don’t have
this problem, one doesn’t actually contain any anti-gel, the other contains a
smaller amount of antigel with large amounts of alcohol to prevent thickening.
Alcohol is about the worst thing to put in an additive.
you have fuel that is gelled, there are only two choices. One warm the fuel up,
generally done by dragging the piece of equipment into a garage, or two by using
a product such as Thaw-It™ to dissolve the wax and reliquefy the fuel.
contains two co-solvents to break down waxes in diesel and glycerin’s in
biodiesel. Thaw-It™ will also remove (disperse) liquid and dissolved
water in the fuel and fuel system.
NOT to Do!
gasoline, ethanol, isopropyl, or methanol is dangerous as it lowers the Flash
Point of the fuel and will likely damage pumps and or injectors.
filter and replace if possible with a new one. If you must use the old filter
try to pour out as much of the ice or gelled fuel as possible. Fill the filter
with 50% Thaw-It™ and 50% diesel fuel. (Do not fill with 100%
Thaw-It™). Add 1 quart of Thaw-It™ per 50 gallons of fuel to the fuel
tank(s). Allow to sit for 20-30 minutes, then start engine. Allow engine to warm
before driving or operating.
Use Complete Fuel Treatment™ or Polar Flow™ to prevent fuel from
gelling in the future. If you have water in your fuel system use EnerFuel to
Copyright January 2009
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