Amazon: FRAM PS10265 In-Line Fuel and Water Separator Water in diesel fuel is like a contaminant. It can erode the surfaces of orifices in precision injectors and cause corrosion in fuel systems. FRAM fuel filter/water separators are specially designed to strip droplet or emulsified water from diesel fuel and contain it in a reservoir at the bottom of the filter.3.2/5(9) in line water separator | eBay 2 product ratings - Wix Fuel Filter Complete In-line 10-micron Water Separator Element 33369 . $21. FAST 'N FREE. or Best Offer. Estimated delivery Thu, May 16. Free Shipping. 95 new & refurbished from $10. In-line Water Separator And Air Filter S & G Tool Aid 99000 SGT TE See more like this.