Filtration Wiki

Filter Element Construction

Filter elements are built using different media and structures to achieve specific filtration goals. Each construction type offers unique performance characteristics suited to various fluids and operating conditions.

• Carbon Block

  Compressed activated carbon that removes contaminants by adsorption on its porous surface.

  Best for: Excellent for reducing chlorine, odor, and organic compounds in water applications.

• Meltblown

  Depth-type filter made by extruding fine polymer fibers into a dense mat.

  Best for: High dirt-holding capacity for general-purpose liquid filtration; cost-effective disposable media.

• Membrane

  Thin microporous media with precise pore size control.

  Best for: Used for absolute-rated filtration, ideal for final polishing or sterilization-grade applications.

• Pleated

  Filter media folded into pleats to maximize surface area within a compact design.

  Best for: Provides high flow capacity, low pressure drop, and extended service life compared to flat media.

• Porous Metal

  Media formed from fine metal powder that is sintered to create a uniform, rigid pore structure.

  Best for: Extremely durable and reusable; available in stainless steel, nickel, and a wide range of exotic alloys for high-temperature, high-pressure, and corrosive applications.

• Rolled Depth

  Layers of fibrous media wound into a dense cylindrical roll.

  Best for: Gradual pore structure provides depth filtration; ideal for viscous fluids and high solids loading.

• Stringwound

  Yarn tightly wound around a perforated core in a helical pattern.

  Best for: Economical and rugged; great for removing coarse particles from water, oils, and chemicals.

• Wire Mesh

  Precision-woven metal screen, often stainless steel.

  Best for: Cleanable and long-lasting; best for coarse filtration, strainers, or applications needing structural strength.

Media Options

Filter media is the material that performs the actual filtration. Different media types are selected based on the application, fluid compatibility, particle size requirements, and operating conditions. Temperatures noted below are for reference only.

• Acrylic

  Synthetic polymer fiber used for general-purpose liquid filtration and low-temperature gas service.

  Max temperature: 200°F (93°C)

• C-276 Hastelloy

  Nickel-molybdenum-chromium alloy offering exceptional corrosion resistance in aggressive chemical and seawater environments.

  Max temperature: 1000°F (538°C)

• Carbon Block

  Compressed activated carbon for adsorption of chlorine, taste, odor, and organic compounds in water applications.

  Max temperature: 140°F (60°C)

• Cellulose

  Natural plant fiber used in economical filters for oil and coolant applications.

  Max temperature: 180°F (82°C)

• Cotton

  Natural fiber commonly used in liquid filtration and prefilters for water, oils and coolants.

  Max temperature: 250°F (121°C)

• Cotton String

  Twisted or wound cotton yarn for depth-type filtration of particulates in liquids.

  Max temperature: 250°F (121°C)

• Cotton/Synthetic Blend

  Mixture of cotton and synthetic fibers offering improved strength and temperature stability.

  Max temperature: 275°F (135°C)

• Cotton/Synthetic/Excelsior Blend

  Blend of cotton, synthetic, and wood fibers (excelsior) forming a deep, porous structure for high dirt-holding capacity in oil and viscous liquid filtration.

  Max temperature: 275°F (135°C)

• Fiberglass

  Fine glass fibers used in high-efficiency filtration for air, gas, and hydraulic fluids.

  Max temperature: 500°F (260°C)

• Microglass

  Ultrafine glass fiber media providing high efficiency and dirt-holding capacity in liquid and gas filters.

  Max temperature: 350°F (177°C)

• Nylon

  Durable synthetic polymer offering excellent abrasion resistance and chemical compatibility.

  Max temperature: 250°F (121°C)

• PTFE Membrane

  Polytetrafluoroethylene membrane providing exceptional chemical resistance and hydrophobic properties for aggressive fluids and gases.

  Max temperature: 450°F (232°C)

• Polyester

  Synthetic fiber media with good strength, chemical resistance, and resistance to hydrolysis and hydrocarbons.

  Max temperature: 275°F (135°C)

• Polyethersulfone

  Asymmetric membrane with high flow rates and excellent chemical resistance for sterile and fine filtration.

  Max temperature: 250°F (121°C)

• Polypropylene

  Widely used thermoplastic polymer with broad chemical compatibility and low cost for general liquid filtration.

  Max temperature: 200°F (93°C)

• Rayon

  Regenerated cellulose fiber with low lint and excellent compatibility for water, oil, and sanitary applications. Withstands steam sterilization and repeated high-temperature cycles.

  Max temperature: 180°F (82°C)

• Resin Impregnated Cellulose

  Cellulose media impregnated with resin and bonded water-absorbing polymer for hydraulic and lube oil moisture removal.

  Max temperature: 250°F (121°C)

• SS304

  Stainless steel alloy with good corrosion resistance for general-purpose liquid and gas service.

  Max temperature: 1000°F (538°C)

• SS316

  Stainless steel alloy with added molybdenum for superior corrosion resistance in chlorides and harsh chemicals.

  Max temperature: 1000°F (538°C)

• Titanium

  Outstanding corrosion resistance, biocompatibility, and mechanical strength.

  Max temperature: 1100°F (593°C)

• White Cotton

  Bleached cotton fiber for clean, low-lint filtration in food, beverage, and pharmaceutical service.

  Max temperature: 250°F (121°C)

Housing Compatibility

Indicates which filter housings can accept a given element based on length, diameter, end cap style, seal type, and connection. Fil-Trek offers Engineered Fit & Function solutions for any existing housing or application—contact us, we're happy to keep you flowing.

No itemized entries in this section.

Filter Element Type

Filter Element Type refers to common industry categories used to describe different styles of filtration products.

• Cartridge

  Standard cartridge filters typically describe 2.5"-2.75" diameter elements used for liquid and gas applications.

• High Flow (HF)

  Larger capacity outside-in flow filters designed for higher flow rates and longer service life than standard cartridges. 6.5" OD, 3" ID with a 338 O-Ring.

• High Flow 700 (HF700)

  High retention outside-in flow filters designed for higher dirt holding capacity and longer service life than standard cartridges. 6.5" OD, 1.6" ID with a 226 O-Ring.

• Ultraflow (UF)

  Larger capacity inside-out flow filters designed for higher flow rates and longer service life than standard cartridges. 6" OD, 3" ID with a 435 O-Ring.

• Gas Particulate Filter

  Used for removing solid particles from gas streams.

• Gas Coalescer

  Removes fine liquid aerosols from gas, promoting droplet coalescence for efficient separation.

• Gas Separator

  Combines particulate and coalescing functions for comprehensive gas filtration.

• Bag Filter

  Sewn or welded filter bags designed for high flow and dirt-holding capacity in liquid applications.

Cartridge End Caps

Available End Cap Treatments for Standard 2.5", 2.75" Cartridge Filter

• E1

  DOE Double Open End with plain cut ends

  Image reference: E1.png

• E2

  DOE Double Open End with flat gaskets

  Image reference: E2.png

• E3

  DOE Double Open End with extended core on one end

  Image reference: E3.png

• E4

  SOE Single Open End with 222 o-ring

  Image reference: E4.png

• E5

  222 o-rings with fin on one end

  Image reference: E5.png

• E6

  SOE Single Open End with 226 o-ring

  Image reference: E6.png

• E7

  226 o-ring with fin on one end

  Image reference: E7.png

• E8

  SOE Single Open End with 226 o-ring and plastic spring on one end

  Image reference: E8.png

• E9

  Plastic Seal spring on one end

  Image reference: E9.png

• E19

  Direct Bond Gaskets

  Image reference: E19.png

Certifications

Industry certifications and approvals for filtration equipment demonstrate compliance with recognized safety, quality, and performance standards.

• ASME

  American Society of Mechanical Engineers code for pressure vessels and piping systems. ASME Section VIII certification ensures equipment meets rigorous design, fabrication, and inspection requirements for safe operation under pressure.

• PED

  Pressure Equipment Directive (EU 2014/68/EU) for marketing pressure equipment in the European Union. PED certification confirms compliance with essential safety requirements for design, manufacturing, and conformity assessment.

• CRN

  Canadian Registration Number issued by provincial regulatory authorities. CRN registration verifies that pressure equipment meets Canadian codes and standards for safe installation and operation.

• NSF

  NSF International certification for drinking water system components. NSF/ANSI Standard 61 ensures materials and products don't leach harmful contaminants into potable water.

• FDA

  U.S. Food and Drug Administration compliance for food, beverage, pharmaceutical, and medical applications. FDA-compliant materials meet regulatory requirements for direct and indirect food contact.

• 3-A

  3-A Sanitary Standards for dairy and food processing equipment. 3-A certification ensures hygienic design and materials suitable for cleanability and product safety in sanitary applications.

Special Service

Service classification used to flag additional design, material, fabrication, and QC requirements beyond standard service for pressure equipment and filtration systems

• Sour Service

  H2S (sour) service—SSC control per NACE MR0175/ISO 15156 or MR0103

• Lethal Service

  ASME VIII-1 lethal service (UW-2)

Internal Lining

Internal linings protect wetted surfaces from corrosion, erosion, and product contamination

• Ceramic

  High-hardness tiles/trowel coatings for erosive slurries and wear zones. Excellent erosion/chemical resistance; low flexibility—control movement/thermal cycling

• Epoxy

  Amine/novolac epoxies for broad service; novolac suits strong acids/solvents.

• PFA

  Fluoropolymer with near-PTFE chemical resistance and very low permeation. Service typically ~200-230°C (per manufacturer); ideal for aggressive/pure media

• ETFE

  Tough fluoropolymer with broad chemical and abrasion resistance. Service ~150-170°C

• Halar

  Chemically equivalent category to ETFE

• Tefzel

  Chemically equivalent category to ETFE

• Rubber Lined

  Natural/synthetic rubber. Strong in mineral acids and abrasion; limited 60-90°C; weak vs. hydrocarbons

Bag Filter Size

Size classification used to flag the size of the bag filter

• Size 1 (P1)

  7" OD x 16" long

• Size 2 (P2)

  7" OD x 32" long

• Size 4 (P4)

  4" OD x 16" long

• Twin Series (TW)

  7" OD x 80" long

Filter Media Rating

Filter media rating describes how effectively a filter removes particles at a specified micron size.

• Nominal

  Nominal rating indicates that a filter can remove a specified percentage of particles at a given micron size, usually around 98% (up to Beta 50). It is an approximate value and may vary depending on operating conditions and test methods.

• Absolute

  Absolute rating represents a much higher and more consistent filtration efficiency, typically 99.9% or greater at the stated micron size. It is often associated with strict performance standards and is commonly defined using Beta 1000 or greater.

• Beta Efficiency

  Beta Rating (β) is a standardized and quantitative measure of filtration efficiency based on particle counting. It is defined as the ratio of the number of particles upstream of the filter to those downstream at a specific micron size. For example, a Beta 5000 rating means that for every 5000 particles entering the filter, only 1 passes through, corresponding to 99.98% efficiency. Beta ratings provide a precise and repeatable way to compare filter performance across different products and applications.