String Wound Filters
United Filters International manufactures the highest quality in cartridge filtration.
UFI string wound cartridge filters provide true depth filtration, high dirt holding capacity, and extremely low media migration. They are a superior, one-piece cartridge manufactured using a high speed, continuous wind process, and are available in a wide variety of lengths and porosities. Especially significant is the availability of filters in an almost endless combination of media and core material, to handle virtually any chemical and/or environment or temperature. U-Series string filter cartridges are available with 14-string, seven core and 12 material and end cap options. Outside dimensions of 2 to 6 inches and lengths of 5 to 72 inches are standard. They can be sized for virtually all single- or multi-round filter housings. The precise winding pattern defines micron ratings and results in higher dirt-holding capacity and efficiency. Our UPDN series of polypropylene string cartridges is Gold Seal Certified to the ANSI/NSF 42/61 standard.
UFI UPDN Municipal Series String Wound Filters
UPDN Series Filter Cartridges have been tested and certified to the ANSI/NSF 42/61 standard to assure continuity of materials and consistency in manufacturing the finished product. Each component is identified and controlled in accordance with the registered wetted parts lists. These cartridges will not impart unwanted leached materials into the downstream flow.
Nominal micron ratings of 0.5 to 200, with 3.75- to 72-inch lengths and 2- to 6-inch outside diameters, offer a wide range of options suitable to most industry standard filter housings. Cartridges are double open ended. Optional end cap treatments available. See below.
UPDN Cartridges are in use at state and federal correctional institutions, office buildings, municipal water districts, Department of Defense road mobile potable water systems, and other applications where the ANSI/NSF 42/61 standard is required.
Filter Core Selection Guide
- Polypropylene: economical core of choice for most applications in water and corrosives to 200ºF.
- Tin Plated Steel: General purpose metal core for oils, solvents,paints, and other non-FDA applications. For use to 400ºF.
- 304 Stainless Steel: For high temperature applications on diluted acids and moderately corrosive fluids. For use to 750ºF.
- 316 Stainless Steel: For high temperature applications on strong acids and highly corrosive fluids. For use to 750ºF.
- Glass-filled nylon for strong acids and highly corrosive fluids when polypropylene is not compatible.
This product has been tested and certified by IAPMO according to ANSI/NSF 42 and 61 for material safety only.
Filter Media Selection Guide
UP Standard Polypropylene String Wound
For concentrated acids and alkalies, strong oxidizing agents, and corrosive fluids and gases. Easily incinerated to trace ash. For use to 200º F.
Ideally suited for potable water, Pharmaceutical and Food Processing Applications.
UPDN NSF42/61 Grade Polypropylene
String Wound
For applications requiring compliance with local, state and federal regulations, where all traceability of all wetted parts is required. This filter is suitable for food, beverage and other potable water applications.
UC Bleached Cotton String Wound
Bleached to meet FDA standards for distilled water, beverages, vegetable oils, petroleum, fatty acids, and alcohols. For use to 300º F. FDA approved.
UK Polyester String Wound
Chemical resistance similar to polypropylene with high temperature resistance. For use to 350º F.
URT Ryton String Wound
Non oxidizing, good for high PH applications even at elevated temperatures. Is chemically resistant with many acids, salt solutions & automotive fluids. Max Temp 425ºF..
UF Fibrillated Polypropylene String Wound
Non-migrating slit film polypropylene free of extractables used in ultra-pure liquids, electronics, and plating where non-leaching is critical. Chemical resistance is equal to standard polypropylene.
UU Natural Cotton String Wound
For oils, water, paints, organic solvents, alcohols, and petroleum. Non-FDA applications. For use to 300º F.
UCCU Econo White Cotton String Wound
Combination bleached cotton outer wrap with natural cotton interior used for non-FDA water treatment applications.
UR Rayon String Wound
Fluid compatibility similar to bleached cotton, but with more coarse fiber and less absorbency than cotton. Swells in aqueous solutions. For use to 300º F.
UN Nylon String Wound
For special process applications, concentrated alkalies, and hydrocarbons. For use to 300ºF.
UG Fiberglass String Wound
Available in both standard and baked media. Baking removes all traces of oil sizing, yielding virgin glass fiber. For use to 750º F.
Multiple End Treatment Options
UFI provides 8 different end caps to all of our filter lines. The diversity of these end caps provides an endless variety of filtration needs for every industry.
We can provide the following end caps:
- Polypro-226
- Polypro Core Extender
- Stainless Steel Core Extender
- Flat/Closed
- Poly-222
- Fin
- Flat/Open
- Plastisol Molded