Choosing the right filter bag and housing is a critical decision for engineers and technicians working across water, chemical, oil, paint, and food & beverage industries. With liquid filtration directly impacting plant uptime, product quality, and safety, it pays to take a systematic, informed approach that goes beyond the generic advice you might find elsewhere. At CLARIBag, we’ve supported hundreds of facilities in specifying, upgrading, and maintaining filtration systems—so here’s our in-depth, actionable take designed specifically for the challenges faced in the UK and European industrial sector.
Step 1: Define Your Filtration Objectives
- What are you filtering? Start with your liquid type—water, synthetic oils, process chemicals, beverage ingredients, paints, or effluents. Knowing your fluid's chemical and physical properties shapes every other filter bag and housing choice.
- Contaminant nature and size: Are you removing sand, metal chips, organic fines, or paint pigments? Estimate the contaminant’s size spectrum (5–1000 microns is typical in industry).
- Target cleanliness level: Food and beverage sectors often require very fine filtration (typically ≤25 micron), while cooling water or paint production may permit coarser removal (25–200+ micron).
Step 2: Select the Right Filter Bag—Material, Micron, and Size
Choosing Micron Ratings
- Fine filtration (5–25 micron): Essential for removing micro-particulates in food production or fine chemical manufacture. For example, the CB-PPF52WN-FB 5 micron Polypropylene Felt is a workhorse for high-purity applications.
- Medium filtration (50–200 micron): For oils or paints, where protection against grit but not ultrafine particles is needed. The CB-PPF2002WN-FB 200 micron Polypropylene Felt fits this niche.
- Coarse filtration (300–1000 micron): For high loading of larger solids—think slurries, process water with debris, or pre-filtration of river water. The CB-NM10002HN-FB 1000 micron Nylon Mesh provides the durability and throughput needed.
Filter Bag Materials (and Why They Matter)
- Polypropylene Felt: Excellent chemical compatibility—acids, alkaline solutions, and many food products. Withstands temperatures up to 80°C. All our felt bags use thermally welded seams and are silicone free, minimizing product contamination risk.
- Nylon Monofilament Mesh: Best for coarse solid loading or precise removal of a particular size; highly durable; ideal for oils, paints, and large solid removal.
Bag Sizes—Match to Your Filtration Load
- Size 1 (7" × 16"): ~8L; suited to pilot rigs, small batch processing, or where frequent changeout is acceptable.
- Size 2 (7" × 32"): ~17L; industry standard for medium to large process flows.
- Size 4 (4" × 15"): ~2.5L; for space-constrained or very low flow applications.
Step 3: Calculate Flow Rate and Pressure Needs
It’s easy to undersize or oversize a filter system—either leads to inefficiency. Here’s what to check:
- Projected system flow: Determine peak and average flow rates (L/min). Filter bags have optimal flow ratings—exceeding this causes rapid blinding or bag damage.
- Size 1 Housings: Up to 300 L/min)*
- Size 2 Housings: Up to 600 L/min*
- Size 4 Housings: Up to 150 L/min*
- For higher requirements, you might need parallel or multi-bag configurations.
- Pressure tolerance: Our stainless steel housings operate up to 10 bar, easily handling most process lines.
* Consider lower flow rates for high viscosity or heavily contaminated liquids.
Step 4: Choose the Correct Bag Filter Housing
Bag Housing Types & Connection Styles
- Single Bag Housings are perfect for compact spaces or frequent product changeovers. Our BFOS2-10/G50-A2 (for Size 2, 2" BSP connections) and BFOS1-10/G50-A2 (for Size 1, 2" BSP) cover most batch and mid-scale operations.
- For high-volume or continuous processing, multi-bag housings may be required (please contact us for custom options).
- Entry/exit orientation: Side-in/bottom-out is efficient and space saving. Optional side in-side out orientation is also possible depending on piping arrangements
- Connection: Choose BSP thread (BFOS2-10/G50-A2) or PN16 flange (BFOS2-10/F80-A2) depending on your piping system.
Housings like our ALSI4-10/G40-C2 are engineered for mini installations where space matters. Always check that your chosen housing matches your process volume and enables ergonomic bag access for maintenance.
Step 5: Confirm Chemical Compatibility and Operating Conditions
- Chemical resistance: Polypropylene suits most acids/bases; Nylon mesh works for oils and solvents. 304 or 316 stainless steel housings withstand common industrial fluids, but aggressive media may need plastic materials like Polypropylene, PVDF or HDPE available from our special range (check your process specs!).
- Temperature limits: Polypropylene bags up to 80°C; housing up to 80°C. Never exceed these ratings for safety and performance longevity.
- Physical location: Consider available room for housing footprint and headroom to open the lid for bag changeout. Our housings feature adjustable legs for easy onsite leveling.
Step 6: Maintenance and Changeout Planning
- Ease of access: All our housings use hinged/lift-off or triclamp lids for fast, tool-free bag changes.
- Drain/vent points: Drain valves and air vents are available as optional accessories on our bag housings for safe and clean operation.
- Monitor pressure drop: Finer micron bags blind quicker—track differential pressure to schedule replacements and avoid filter burst or bypass.
- Safety tools: Dedicated opening tools and maintenance aids are available for our full housing range.
Step 7: Consult Technical Documentation & Get Expert Support
When in doubt, reference our technical datasheets for every product's compatibility, flow, and pressure data. If your application is complex or novel, we encourage a discussion—our team regularly assists with bespoke solutions, from unusual fluid types to ultra-high volume systems.
Quick Reference Table — Example CLARIBag Solutions
| Application | Micron Rating | Material | Example Bag |
|---|---|---|---|
| Paints & Pigments | 25–200 | Polypropylene Felt or Nylon Mesh | CB-PPF252WN-FB |
| Food & Beverage | 5–25 | Polypropylene Felt | CB-PPF52WN-FB |
| Wastewater | 100–200 | Polypropylene Felt | CB-PPF2002WN-FB |
| Oils/Cutting Fluids | 50–1000 | Nylon Mesh | CB-NM6002HN-FB |
Checklist for Specifiers and Engineers
- Clarify the liquid and contaminant involved
- Match micron rating and filter material to process needs
- Check required flow rate and pressure—size housing accordingly
- Verify chemical resistance and temperature suitability
- Review installation layout (space, connection type)
- Anticipate access for regular bag changes and cleaning
- Consult available technical documentation or contact CLARIBag for tailored advice
Engineered for UK and European Industry—What Sets CLARIBag Apart
At CLARIBag, we don’t just ship product—we partner with plant managers, engineers, and maintenance teams to pinpoint the most resilient, efficient filtration approach for your unique process. From individually wrapped, food-grade compliant filter bags to compact or industrial-scale housings with all the right maintenance features, we bring together the durability and technical clarity you expect.
If you're ready to upgrade your liquid filtration—or you're specifying a system for a new plant—browse our complete filter bag and housing catalogue or reach out to our filtration engineers for direct support.
