A two stage filtration system should be used where the maximum amount of water removal is required. The system also allows for fine contaminant removal. Clean and dry fuel is a must and it is accomplished by coalescing the fine droplets of water found in fuel and separating them from the product stream.
The image above illustrates the progression of the product stream through coalescer media. The emulsion is broken apart, filtering the solids, then forcing the minute water particles to coalesce (to consolidate or join up) into larger droplets. Gravity pulls the larger droplets to the bottom of the filter housing allowing it to be drained off during filtration. This is the first of two phases.
The second phase involves separation. A Teflon coated water separator filter, like the one above, is used to repel fine droplets of water that happen to remain from coalescence. This second stage acts as a secondary back-up forcing the water out of the product flow – not allowing it to pass through with the fuel. It works because Teflon is hydrophobic (literally, afraid of water). The water repels off of the coated separator and falls down to the bottom of the filter housing where it can be drained off leaving the fuel clean and dry.
When looking for a filtration system, look for ones that provide the efficiency of coalescing and water separation. Dixon’s new filtration designs include the technology.