Q:Philip, Dublin, Ireland
I was interested in the article by Nigel Calder in the February 2012 edition on the H2OUT dehumidifier and think it is something that I might install. I have been keeping my fuel tank topped up to minimize condensation. While there is a fuel gauge, it’s down below, so the only practical way to ensure a full tank is to pour fuel in until it comes up near the top of the fuel inlet. However, by then the fuel has risen up the air vent and eventually leaks out the side. What effect does diesel have on the blue beads in the H2OUT filter? Also, is there some change I should make to the air vent?
Nigel Calder Replies
Unfortunately, the diesel will coat the granules in the filter and render it more or less inoperable. It is possible to wash the crystals in detergent, dry them out, and then reuse them, but I don’t think you will want to do this every time you fill the tank! You could fit a diverter valve ahead of the filter with a line coming into a collection bottle and use this when taking on fuel to determine when the tank is full. Afterward you could switch back to the filter in the vent line. This would also help to ensure that you do not spill any diesel. Another approach would be to get fittings that shut off the air vent if the diesel rises to this level. Essentially, there is a ball in the fitting that floats up and blocks the outlet, at which point you will see the diesel rising up your fill fitting and can stop filling. However, using this approach it is also possible to trap air in the tank and then have this blow back through the fill fitting, spraying out diesel! It all depends on the internal layout of the tank and the position of the fill and vent fittings.
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