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True Depth Filtration for Extreme Conditions

The Purewound Series is not just a filter; it is a high-capacity “dirt-trap” designed for the most challenging fluid streams.

High Dirt-Holding Capacity: Our precision winding pattern creates a graded density that traps larger particles on the surface and finer particles deep within the core.

Extreme Temperature Resilience: When wound on specialized stainless steel cores, the Purewound Series can operate in environments up to 400°C, making it the definitive choice for high-heat industrial processes.

Low Media Migration: We use long-staple natural cotton fibers to ensure that the filter itself doesn’t become a contaminant, providing a clean filtrate every time.

Targeted Removal of Industrial Contaminants

The Purewound Series is engineered to provide a high reduction of:

Abrasives: Sand, silt, and grit that can damage high-pressure pumps.

Corrosion Products: Rust and scale particles from aging pipeline infrastructure.

Heavy Sediment: Ideal for “dirty” water and industrial chemical streams.

Critical Applications Across Global Markets

Sector	Application	The Purewound Advantage
Oil & Gas (Middle East)	Produced Water & Brine Filtration.	Survives the high-heat and high-pressure demands of the Gulf’s extraction sites.
Power Generation (USA/Europe)	Boiler Feedwater & Condensate.	High-temperature resistance ensures stable filtration in steam-heavy loops.
Chemical Processing	Organic Solvents & Oils.	Natural cotton is compatible with many chemicals that degrade synthetic polymers.
Marine & Defense	Engine Room & Fuel Pre-filtration.	A cost-effective, rugged solution for removing rust and scale from heavy fuels.

Purewound Cotton Filter: Frequently Asked Questions

Q1: What makes “Purewound” cotton filters different from standard melt-blown filters?

Answer: Unlike melt-blown polypropylene, Purewound Cotton filters are manufactured using a continuous winding process that creates a “diamond” pattern. This provides deep-bed filtration, allowing the cartridge to trap particles throughout its entire thickness rather than just on the surface. This results in a higher dirt-holding capacity and longer service life for heavy-sediment applications.

Q2: What are the temperature limits for K Filter Cotton elements?

Answer: One of the primary advantages of cotton is its thermal resistance. While standard plastic filters fail at high temperatures, our Purewound Cotton filters can typically operate safely up to 70°C  when paired with a stainless-steel core. This makes them ideal for hot water, oils, and industrial resins.

Q3: Should I choose Bleached Cotton or Natural (Unbleached) Cotton?

Answer: It depends on your application:

Bleached Cotton: Best for potable water, food, and beverage applications. It is cleaned to meet FDA standards and ensures no flavors or odors are imparted to the fluid.

Natural (Unbleached) Cotton: Ideal for industrial oils, solvents, and non-potable water. It contains natural oils from the cotton plant, which can provide slightly better compatibility with certain organic solvents.

Q4: Are Purewound Cotton filters compatible with aggressive chemicals?

Answer: Cotton has excellent compatibility with many alcohols, hydrocarbons, and mild alkalis. However, it is not recommended for strong acids or strong oxidizing agents. For high-acid environments, we recommend our Polypropylene or Glass Fiber wound options.

Pro-Tip: Always verify the core material (Polypro, Tin-plated steel, or Stainless Steel) to ensure it matches the chemical compatibility of the cotton yarn.

Q5: What micron ratings are available for K Filter Purewound elements?

Answer: We offer a wide range of precision-wound ratings to meet specific purity requirements, typically ranging from 0.5 micron for fine polishing up to 150 microns for coarse pre-filtration.

Q6. Does the string “shed” into the liquid?

No. Our Purewound technology uses a specialized spinning process that creates extremely low media migration. The fibers are locked into the winding pattern, ensuring that “string lint” does not enter your clean process stream.

Q7. Is this filter “True Depth” filtration?

Yes. Unlike surface filters (like mesh), a string-wound cartridge is a depth filter. This means the entire thickness of the cartridge is used to trap dirt. This is why Purewound filters can hold a massive amount of sediment before the pressure drop requires a change-out.

Q8. Is it compatible with standard filter housings?

Absolutely. We manufacture Purewound cartridges in standard lengths (10″, 20″, 30″, 40″) and diameters (2.5″ Standard and 4.5″ BB) to fit almost all industrial housings in the USA, Europe, and the Middle East.

Q9. How does the 400°C rating work?

The 400°C rating is achieved when our high-purity natural cotton is wound onto a 304 or 316 Stainless Steel core. While the cotton will eventually carbonize at extreme sustained heats, its structural integrity in high-heat fluid/gas streams is vastly superior to any plastic-based filter.

Comparison Table for Quick Reference

Feature	PureWound Cotton	Standard Polypropylene
Max temperature	Up to 700C	Up to 600C
Best For	Oils, Solvents, Hot water	Drinking Water, Acids
Filtration Type	Depth Filtration (String wound)	Surface/Depth (melt-blown)
Core Options	Poly, Tin or Stainless Steel	Usually, Polypropylene

Cross-Compatibility: Purewound filters fit standard housings or filters like Pentair WP Series, Pentair Omnifilter RS2 Series, Pentair CW Series, Pentair WF Series, Parker Fulflo Honeycomb, Parker SWC series, Hall Pyke, or Pall.