Custom Pleated Stainless Steel Filter Cartridges

Pleated filter cartridges constructed from stainless steel provide a reusable barrier for fine particulate removal in liquid and gas streams. The pleated geometry increases effective filtration area while maintaining a compact cartridge footprint, allowing higher flow rates at lower pressure drop compared to depth‑type media of the same nominal size.

Material Selection and Corrosion Resistance

Stainless steel grades 304 and 316L are commonly offered for pleated cartridges. Grade 304 delivers a minimum yield strength of 215 MPa and a pitting resistance equivalent number (PREN) of approximately 18, suitable for mildly corrosive water‑based processes. Grade 316L adds molybdenum, raising PREN to about 24 and improving resistance to chloride‑containing environments, which is essential for chemical‑processing or marine applications.

• 304 stainless steel – good general purpose, cost‑effective
• 316L stainless steel – enhanced chloride resistance, preferred for saline or acidic media
• Duplex 2205 (available upon request) – higher strength and superior pitting resistance for aggressive chlorides

Pleat Geometry and Filtration Area

The pleat height, pitch, and number of folds determine the effective surface area. Typical pleat heights range from 10 mm to 25 mm, with pitches of 2 mm to 4 mm. A cartridge with a 20 mm pleat height and 3 mm pitch can provide up to 2.5 m² of filtration area per 250 mm length, which translates to a lower pressure drop for a given flow rate compared to a non‑pleated sintered metal filter of equivalent dimensions.

• Pleat height: 10 mm – 25 mm
• Pleat pitch: 2 mm – 4 mm (center‑to‑center)
• Number of pleats per 250 mm length: 30 – 80 depending on pitch

Customization Options

Cartridges can be tailored to fit existing housings or to meet specific process requirements. Dimensional adjustments, end‑cap configurations, and optional surface treatments allow the filter to integrate seamlessly into a wide range of equipment.

• Outside diameter: 25 mm – 150 mm (standard increments)
• Length: 100 mm – 1000 mm (custom lengths available)
• End‑cap types: double open end (DOE), single open end (SOE), threaded, flange, or sanitary clamp
• Surface finish: pickled & passivated, electropolished, or coated with PTFE for non‑stick properties
• Optional inner support cores: polypropylene, PTFE, or stainless steel mesh for added mechanical strength

Typical Applications and Process Benefits

In chemical processing, the corrosion resistance of 316L stainless steel allows the cartridge to withstand acidic cleaning‑in‑place (CIP) cycles without degradation, maintaining consistent filtration efficiency over hundreds of cycles.

Food and beverage producers favor electropolished finishes because they reduce surface roughness to below 0.2 µm Ra, minimizing microbial adhesion and facilitating sanitary inspection.

Pharmaceutical manufacturers rely on the ability to sterilize the cartridge by steam‑in‑place (SIP) at 121 °C or higher; stainless steel retains mechanical integrity after repeated autoclaving, unlike polymeric media that may suffer creep or leaching.

• Chemical processing – resistant to aggressive solvents and acids
• Food & beverage – compatible with CIP/SIP, meets 3‑A sanitary standards
• Pharma – withstands repeated sterilization, low extractables
• Water treatment – durable under high‑pressure backwash, suitable for pretreatment of RO membranes

Quality Control and Testing

Each cartridge undergoes dimensional verification using calibrated calipers and coordinate‑measuring machines to confirm OD, length, and pleat geometry within ±0.1 mm tolerance.

Material certification is provided for every batch, including mill test reports that confirm chemical composition and mechanical properties (e.g., tensile strength ≥ 520 MPa for 316L).

Integrity testing is performed by bubble point or pressure‑hold methods to validate that the pleated media exhibits no gross defects or bypass pathways before shipment.

• Dimensional inspection: OD, length, pleat height, pitch
• Material traceability: mill test reports, heat numbers
• Integrity test: bubble point ≥ 0.2 bar (water) for 5 µm rating
• Visual inspection: surface finish, weld quality, end‑cap alignment

Frequently Asked Questions

For a technical quotation or to discuss specific process requirements, please contact our engineering team.