Food and dairy engineers routinely manage filtration duties at 120 L/min flow rates, 6.5 bar maximum operating pressure, and 0.2 micron retention targets. These parameters define baseline hygienic performance for liquid handling where particulate control, microbial ingress prevention, and repeatable cleanability are non-negotiable. The Liquid Filtration range addresses these constraints through geometrically optimized housings, validated surface finishes, and material-compatible filter media—all built to meet the physical and procedural expectations of 3-A Sanitary, EHEDG, USDA, and cGMP frameworks without requiring field modifications.
Hygienic Housing Architecture
Housing geometry directly governs cleaning efficacy and residual hold-up volume. Top-entry designs like the FZ Top Entry Bag Filter Housing minimize dead legs and enable full drainability when installed with a 1.5° minimum slope. Side Entry Bag Filter Vessel configurations suit space-constrained skids but require careful attention to gasket seating force and flange alignment during maintenance. All vessels use electropolished 316L stainless steel with Ra ≤ 0. 4 µm finish, verified per ASTM E1815, and incorporate crevice-free clamping—V-clamp Quick Open Multi-bag Filter Vessel and Rotating Open Multi-bag Housing both eliminate threaded fasteners in wetted zones.
Filter Media Selection Logic
Media choice must reconcile retention efficiency, chemical compatibility, and clean-in-place (CIP) resilience. Polyester Needle Felt Filter Bags handle hot caustic rinses up to 85°C but exhibit lower abrasion resistance than Nylon Monofilament Filter Bags in high-velocity slurry service. Multi-layer High Efficiency Filter Bags deliver graded porosity without binder migration, while Welded Filter Bags eliminate stitch channels that harbor biofilm. For extended run times between changeouts, Extend Life Filter Bag uses thermally bonded support layers—this improves durability at the cost of slightly higher initial pressure drop across the same nominal rating.
Cartridge Performance Boundaries
Membrane Pleated Filter Cartridges achieve absolute retention down to 0.1 micron but require strict prefiltration to avoid rapid blinding. Yarn Wound String Filter Cartridges tolerate higher solids loading but show progressive pore narrowing under variable flow. High Flow Filter Cartridge elements reduce footprint by consolidating surface area into radial pleats—this delivers 3× the throughput of standard pleated cartridges in identical housing dimensions. In practice, users report consistent 15–20% longer service intervals when pairing High Flow Filter Cartridge with upstream bag prefiltration in clarified whey streams.
Comparative Housing Attributes
The table below summarizes key mechanical and operational attributes across three multi-bag housing families:
| Housing Type | Max Operating Pressure (bar) | Cleaning Method | Bag Capacity (units) | Opening Mechanism |
|---|---|---|---|---|
| Duplex Bag Filter Housing | 10 | CIP/SIP compatible | 2 | Manual dual-flange |
| Vertical Open Multi-bag Housing | 6.5 | Manual access only | 6–24 | Top-hinged lid |
| V-clamp Quick Open Multi-bag Filter Vessel | 8 | CIP/SIP compatible | 4–16 | Single-turn clamp |
V-clamp vessels balance speed and pressure capability most effectively.
Application Limits and Trade-offs
This selection does not apply to continuous high-temperature steam sterilization above 135°C or to applications involving aggressive oxidizers like peracetic acid above 200 ppm concentration. The Economical Bag Filter Housing should not be used in final product polishing stages where bioburden reduction is required. Its simplified gasket system and reduced wall thickness introduce limits on fatigue life under cyclic thermal stress. A known trade-off exists between filter bag seam integrity and production cost: Stitched/Sewn Filter Bag construction allows faster manufacturing but introduces a potential path for particle shedding versus Welded Filter Bag, which eliminates thread paths entirely.
- Activated Carbon Filter Bag for off-flavor removal in juice clarification
- Oil Absorption Filter Bag for lubricant carryover in CIP return lines
- SS316 wire mesh filter bag for coarse prefiltration ahead of membrane systems
For food and dairy engineers evaluating full-system integration, the Liquid Filtration portfolio provides documented dimensional, material, and surface-finish consistency across housings and consumables. This reduces validation effort compared to mixing components from disparate sources. Note that Dust & Flue-Gas Filtration and Air & HVAC Filtration solutions follow distinct design protocols and are not interchangeable with liquid-handling products.
Common questions on liquid filtration
Is a bag housing or a cartridge housing the right choice?
Bag housings hold one to twenty-three bags and suit a higher solids load, because a loaded bag can be lifted out whole. Cartridge housings pack four to eighteen elements into a smaller footprint and hold a seal more easily at higher differential pressure.
Which sizes and ratings are standard?
Cartridge vessels are built around 5 inch, 10 inch, 20 inch, 30 inch and 40 inch element lengths. Bag housings use Size 1 with a 15 inch basket and Size 2 with a 30 inch basket. Felt and monofilament bags are commonly rated at 1, 10, 25, 75, 100 and 200 micron.
Does a finer micron rating always mean cleaner product?
No. A finer element removes more, but it also loads faster and raises differential pressure sooner, so the change-out interval in days shortens. The rating has to be chosen against the particle size you actually need to remove, not against the finest one available.