In certain applications like aviation refuelling, where the presence of water is causing danger due to freezing at high altitude, water absorbing cartridges are used as a final treatment to assure that all water - including the chemically emulsified part - is removed from the fuel before it can cause danger. Since the water absorption capability is used as safety device the water absorbing cartridges are referred to as 'Monitors'. Since fuels can hold large amounts of water the treatment in the fuel with monitors is restricted to the final stage only. In the rest of the chain the fuel is normally treated with filter/water separators.
Fuel monitors are filter vessels equipped with absorptive elements perform two jobs with one element. It absorbs water an d removes solids reliably and efficiently. As the product stream flows from the outside of the element to the inside, the special water absorbent medium retains water, and the pleats expand. As the maximum water holding capacity is reached, there is a reduction in flow. The element slows, then stops the flow of product as it reaches maximum capacity. This indicates that the element is ready to be changed, assuring you of clean, dry product.