New Styles of String Wound Filter Cartridges
String wound filter cartridges have been traditionally used as a means of low cost, economical filtration. These filters have been limited to mostly 2-1/2″ outside diameter (sometimes 4-1/2″ OD). Though these are ideal sizes for small flow applications, high flow rate applications resulted in cumbersome, high volume filter changes. As a result, users have gravitated towards bag filter vessels.
Bag filter changeouts are much less time consuming and more economical when compared to cartridge filters. However, in some instances, filter life is greatly reduced, especially when dealing with organics, such as algae, or soft particles and silt. These types of contaminants will quickly blind off traditional filter bags resulting in frequent filter changes.
Coleman Filter has developed a string wound bag filter replacement. It is a large string wound filter cartridge with an inside to out flow pattern, designed to fit in standard #2 bag filter housings. These cartridges allow for the benefit of using economical bag filter vessels while reducing filter change outs by 20 times. This is ideal for high labor rate or remote areas; one change out can pay for the difference.
The depth offers higher removal efficiencies when compared to standard bag filters.
The picture above illustrates the effectiveness of the depth filter media. Dirt is captured from the outside all the way to the core.
High Flow Filter Vessels accept 6.25″ x 40″ filters. These cartridge use pleated filter media. Filters are commonly rated for up to 500 GPM. String wound replacements is a economical alternative to these types of filters.
These are used in industrial water, RO prefiltration, coolants boiler condensate, aqueous salt solutions petrochemicals, produced water, enhanced oil recovery, completion fluids, amine sweetening, process water. A variety of medias, cores and micron ratings are available.
The UltiString is an economical alternative to the Pall UltiPleat(TM) pleated element. In applications where true depth filtration and/or higher flow rates are critical to your business. Depending upon the micron, flow rates of up to 500 GPM (at 150 PSI) can be achieved.
Flowing inside to outside, these filters provide more depth (over 1100 cubic inches) to trap and remove a larger volume of particles and contaminants that their pleated competition.

These products are ideal for use in process water systems including:
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Petrochemicals
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Food & Beverage
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Waste Water
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Produced Water
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Enhanced Oil Recovery
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Completion Fluids
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Reclaimed Water
- Produced Water
- High algae / bio applications