John Detuna of Washington, NJ, asks:
Not much has been said about the quality of the fuel you've encountered so far. I know you change out filters regularly. Would you speak to the subject of refueling abroad generally, as well as to any precautions you take yourselves. Do you take and test samples? Do you have an inline filter during fueling? Do you use any biocides or other additives and conditioners?
Jim Leishman responds:
We have been lucky with fuel for the whole trip. Fortunately, we have arranged for fuel from reputable sources and have always been able to take it on from either trucks on the quay, fuel barges which come along side the boat or rarely from fuel docks. We always questioned the fuel vendors and the answer is always the same:"yes it's clean fuel free of water".
Our fuel system is unique and has proven to work perfectly. The fuel drains from the bottom of each of our two 460 gallon fuel tanks into a two-gallon supply reservoir which is positioned in front of our engine via 3/4 inch feed lines. We can select the port or starboard tank or run with both tanks open. The fuel drains into the supply reservoir and most contaminates and water will settle to the bottom of the reservoir. The engine, generator, wing engine transfer line and heater supply all draw off the reservoir - about 2/3 of a gallon from the bottom. The bottom of the reservoir tapers to a "V" and has a pet cock at the lowest point. Slightly below the pickups is a water sensor which sounds an alarm in the wheelhouse if water is detected. The valve at the bottom of the reservoir should be opened after each fueling to determine if any water and sediment has settled into the tank. If so, drain it out. We would check this valve every few days while underway to further check the sump contents.
We use a RACOR 900 duplex filter with a vacuum gauge as our preliminary filter which is located about a foot from the supply reservoir. Slightly below the level of the supply line within the filter we are using 2 micron filters. This installation works well because the fuel filters are always under a slight head of pressure as any fuel is always above the filter level. Changing a filter is very simple - just turn the filter selection valve to the filter in use and the remaining filter can be opened up, the element removed and a new filter dropped into position. Turning the selection valve to both allows the engine to continue to run and the opened filter to be filled eliminating any trapped air. Screw the cap back into position and the filter is ready to be used. The gravity feed eliminated any need to use a priming pump. We have found that the supply reservoir is so effective as a sediment and water trap that the filter elements have lasted hundreds of hours. We actually ran off of one filter from the launch of the vessel until it's return from Alaska - after about 1,000 hours. The vacuum gauge was still showing positive pressure and could have been used even with a considerable vacuum showing.
On the engine we have another fuel filter and water separator. This filter is supplied by John Deere and is a 6 micron filter. We have changed it three times during the 4,000 hours that we have accumulated so far. It has never shown any water in the bowl and we assume the element is still clean with the 2 micron filters in the RACORS doing all the work. It's important to change this filter as there is really no way of knowing if it's beginning to clog - there are no vacuum gauges to alert you like on the main filters.
An additional benefit of the supply reservoir - beyond the cleaning and water stripping of the fuel - is checking fuel consumption. On the front of the reservoir we have a sight gauge which measures one full gallon of fuel divided into one-tenth gallon increments. While running along at any given weight and rpm, the reservoir feed lines from the tank can be shut off and the return fuel directed back to the reservoir then - with a stop watch - a check can be made noting how many tenths of a gallon of fuel are consumed during a 15 minute check. Multiply the tenths by four and you have your hourly consumption. I was able to determine that the generator consumed only .29 gallons of fuel per hour with the AC running by conducting the check while anchored.
This is a great fuel system and whenever possible we will incorporate into all future designs.
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