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NORA Oilheat Technicians Manual

To reduce sludge formation: • Never pump oil from one tank to another. You may be transferring tank killing sludge. • Slow down delivery rates—high pressure filling can stir-up existing sludge causing it to be drawn into the oil line. • Routinely check the tank for water— once you have removed the water, if possible, clean the sludge from the tank and treat the tank with a fuel conditioning additive. • Draw the oil from the bottom of the tank—As water will condense and collect in all tanks, it is best to draw off the water as if forms. It will burn off in the combustion process. Allowing water to accumulate will create conditions favorable for the formation of sludge. • The exception to this rule is outdoor above ground tanks. In cold weather, the water in the bottom suction line may freeze, causing a blockage and no heat. It appears that the best solution to this problem is to run the suction line into one of the top tappings on the above ground tank, use a floating suction line device, and regularly remove the water that condenses in the bottom of the tank. Low temperature performance As oil gets cold, several bad things happen. First, any water in the fuel freezes, plugging lines and filters. Second, the viscosity of the oil begins to increase, causing burner operation problems. Third, wax crystals begin to form in the oil. This wax or paraffin is a natural component of heating oil. Oil temperature is the main factor in changing oil viscosity. As the 2-8 Heating Oil and Its Properties temperature of the oil goes down, the viscosity goes up. The oil gets thicker, which can cause a smoky fire. How to deal with “frozen” tanks and oil lines Cold-flow additives, called Pour Point Depressants, can help avoid frozen lines, but once the tank or lines have frozen or waxed, other solutions are needed. The best solution is to top off the tank with kerosene. The agitation of the fuel in the tank caused by the kerosene delivery and the solvency of kerosene break up and dissolve the wax crystals. You may also have to remove the filter temporarily, convert to a one-pipe system and heat the suction line with a hair dryer or heat lamp. If you are unable to arrange for a delivery, some technicians report that adding as little as five gallons of kerosene can help. Others report having success “shocking” the tank with a pour point depressant. You may have to build a temporary shelter for the tank out of plywood or cardboard, whatever is at hand, and then use a heat lamp or hair dryer to warm up the lines enough to get the oil to flow. Be very careful with heat tape. If you wrap a heat tape over itself, it can burn through its own insulation causing a short that can result in a fire. The insulation on the wires can also crack with age and exposure to the elements creating potential for a fire. Chapter 2 Heating Oil


NORA Oilheat Technicians Manual
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