How are filter cartridges used and how do they work?
Filter cartridges are used to fulfill contaminant control and fluid cleanliness requirements by removing contaminants from water, oils, solvents, fuels, aqueous solutions, and other fluids. Filter cartridges can be used as a pre-filter for particulate removal or as a final filter for virus filtration, or microbial removal. They may also be validated as sterilizing grade or for microorganism reduction.
Typically, a depth-style filter cartridge will capture contaminants at multiple levels within the tapered pore structure. Pleated filters and those with a more uniform pore design, use surface filtration where contaminants larger than the pore size of the media will be trapped on the surface. These cartridges are typically placed inside a housing (vessel) where the fluid will flow through to be filtered.
Filter Cartridge Configuration and Construction Styles
- Depth (melt-blown)
- Pleated (conventional fan-pleat or laid-over pleat)
- Wound (string wound or spiral wound)
Filter Medium and Membranes
- Polymeric/Synthetics – Polypropylene (PP), polyphenylene sulfide (PSS), polyethersulfone (PES) and nylon
- Membranes – Fluoropolymers (e.g., polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) (hydrophilic) and polyester (PE)
- Yarns – Cotton, glass fiber, polypropylene, polyester, nylon and polyphenylene sulfide (PPS)
Food Contact Compliance (W-Code)
In line with the high-quality requirements and stringent regulations around food safety, Pall developed a comprehensive portfolio of products compliant to the latest food contact regulations for the food and beverage industry. The portfolio includes a full range of products from depth filters for particle removal to membrane filters qualified for removal of market-specific bacteria and spoilage organisms that can adversely impact taste and product shelf-life. Cartridge filter products within the portfolio are noted with “W” in the part number or material description.
Specific Declarations of Compliance for these filters are available on the Pall website. These “Declaration of Compliance” statements are reviewed on an ongoing basis to ensure compliance with new or updated regulations. Please refer to the following link for a Declaration of Compliance to specific National Legislation and/or Regional Regulatory requirements for food contact use, and to consult applicable part numbers.
Compliance Documentation For Food Contact Applications
Pharmaceutical (P-Code) Sterilizing Grade Filters
Pall’s pharmaceutical-grade filters are designed for use in conformance with CGMP in Manufacturing, Processing, Packing, or Holding of Drugs (21CFR210) and CGMP for finished Pharmaceuticals (21CFR211.72) including batch release certificate and full traceability. P-Code at the end of part number or noted in the description indicates optimized and qualified for Pharmaceutical use, including encapsulated stainless-steel reinforcing adapter ring for in situ steam sterilization, 100% integrity testing and Certificate of Test provided. When in doubt, contact a Technical Specialist to confirm product specifications and compliance.
For further reference, see also Pall’s Product Quality Conformance Documentation.
Shop Pall’s Filter Cartridge Options:
Depth Filter Cartridges
Depth (melt-blown) filters are constructed using a computer-controlled process where fibers are deposited onto a rotating center core, forming a tapered (graded) pore structure. This structure offers very high mechanical strength, long service life and efficient contaminant removal. Depth filters are often used for gel removal and allow for higher retention in fluids when there is a wide particle size distribution of contaminants.
Pleated Filter Cartridges
Pleated filters are formed from a media or membrane sheet into a pleated cylinder cartridge. Pall offers pleated filters in both a conventional fan pleat geometry as well as a patented laid-over pleat, which provides higher surface area for higher dirt holding capacity and longer life. Pleated filters are used for fluids with a narrower particle size distribution and where high flow rates are required, providing low pressure drops.
Pleated-Depth Filter Cartridges
Pleated-depth filters are a cartridge format made from thick melt-blown depth filter media with a tapered pore structure. A pleated-depth filter hybrid combines the exceptional dirt-holding capacity of depth filters with the high flow rates of pleated filters.
String-Wound Filter Cartridges
String-wound filters are a format of depth filters with graded pore structure formed into a cylinder using yarn wound or woven around a core with high precision. Wide compatibility is available with materials used such as cotton, glass fiber, polypropylene, polyester, nylon and polyphenylene sulfide (PPS), wound around a core usually of 304 SS or 316 SS. String-wound filters offer an economical solution for long service life and high contaminant loading capacity where chemical and temperature compatibility are a challenge.
Lube & Hydraulic Filter Elements
Featuring Stress-Resistant Technology (SRT), our lube and hydraulic elements are available in laid-over-pleated designs. With cage-less construction, these filter elements have inert, inorganic fibers that are securely bonded in a fixed, tapered pore structure. Pall’s filter elements provide optimum performance under system stress at all stages of filter life, along with low clean pressure drop.
