From protecting pumps and heat exchangers in water treatment, to ensuring particle free beverages or clean chemical products, filter bags touch nearly every part of industrial and food production. Here at CLARIBag, we know the choices can feel overwhelming. Let's walk through five genuinely critical criteria that will help you make confident, informed decisions that suit water, chemical, and food applications.
STEP 1. Application: Know What You Need to Remove
Your application always comes first. Are you targeting coarse grit in wastewater, yeast in beer, fine solids in chemicals, or seeds in a juice line? The size and type of contaminant—and how critical its removal is—dictates your primary requirements.
- For coarse solids (rust, sand, seeds): Consider filter bags with larger micron ratings (e.g., 100–1000 µm). Mesh types work well for visible particulates.
- For fine particles or haze: Reach for lower micron ratings (1–50 µm). Felt bags provide depth filtration, capturing particles at various layers.
- For viscous or gelatinous substances: Multilayer or high dirt-holding bags are preferable to prevent clogging and extend filter life.
Getting the application right means better product quality, reduced equipment wear, and compliance with industry standards. For more, see our application guides tailored to water, sidestream, wastewater, and food & beverage processes.
STEP 2. Match Micron Rating with Your Process Targets
Micron rating is the core metric for filter selection, defining what particle size will be retained. But actual results depend on several factors. At CLARIBag, we offer bags from 1–200 µm in felt and 1–1000 µm in mesh, supporting a wide range of needs.
- 1–5 µm: For ultra-fine filtration (final clarification, polishing)
- 10–50 µm: Particle removal for equipment protection and quality improvement
- 100–200 µm: General solids removal (sand, silt, seeds, rust scale)
- 500–1000 µm: Coarse straining (large debris in wastewater or food intake systems)
We recommend always trialling the micron rating before large-scale adoption. Analysis of particle size distribution or historical system data gives the best starting point. Our filter bag selector tool can help you get a quick shortlist for your application.
STEP 3. Filter Media Compatibility
Incompatible filter media can result in premature filter bag failure. It is important to ensure chemical and thermal compatibility before putting the filter bags into service.
- Polypropylene Felt: Excellent for broad chemical resistance, acids, bases, and most food & beverage uses (max 80°C). Used for water, chemicals, and industrial liquids. Food compliant, silicone-free, widely used for standard and critical duty.
- Polyester Felt: Increased temperature tolerance (up to 120°C) and good organics/oil handling. Suitable for hot process water, solvents and fuels.
- Nylon Monofilament Mesh: Best for precision straining (viscous liquids, syrup, honey, oils, or pulp separation). Low extractables, food compliant, handles up to 120°C (SS ring versions). Perfect when no fibre release can be tolerated.
Always verify the filter media's suitability for your process. Polypropylene is usually safe with acids, bases, and alcohols, but should not be used with strong oxidizers. If you are unsure, reach out to our team, we help assess chemical compatibility and can provide test samples.
STEP 4. Select the Correct Size and Housing Compatibility
The filter must properly fit your housing to prevent bypass and achieve full-rated performance. Standard filter bag sizes are:
- Size 1: 7" x 16" (0.25 m², up to 18 m³/hr, ~8L volume)
- Size 2: 7" x 32" (0.5 m², 17L volume, up to 40 m³/hr)
- Size 3: 4" x 9" (0.05 m², ~1.4L volume, lower flow/batch work, up to 9 m³/hr)
- Size 4: 4" x 15" (0.1 m², ~2.5L volume, up to 9 m³/hr)
Flow rates are correct for water applications, these should be reduced for viscous applications
Collar types (moulded W collar, Eaton H collar, etc.) must also match your housing for a secure seal. CLARIBag offers universal W collar (fits FSI/Pall) and compatible H collar for filter housings manufactured by Eaton. If you're retrofitting or unsure about fit, contact us directly for advice or custom solutions.
STEP 5. Always Account for Flow Rate, Load, and Maintenance Intervals
Undersized bags or filters overloaded by dirt quickly result in increased operating costs, downtime, and potential product loss. Proper sizing means understanding your maximum system flow, expected solids load, and maintenance routines.
Size for actual flow but add a safety factor (e.g., 0.7 for moderate water, more for dirty systems)
For high-solids or viscous applications, consider larger bag surface area or parallel bags to extend life and avoid excessive pressure drop.
Monitor the differential pressure (DP) across the filter; replace when the DP reaches 1 bar (recommended for most bag housings) or when flow diminishes.
Follow documented changeout schedules and inspect the housing/collar area for signs of bypass or seal degradation.
Accessories such as pressure gauges or automatic air vents can help with maintenance for large or critical systems.
Special Considerations by Application Type
Water & Wastewater
Polypropylene felt, 25–100 µm covers most general treatment needs
Use multi-bag or larger size housings for higher solids
Chemicals
Polypropylene or specific specialty media based on chemical compatibility
Verify bag construction (welded seams if you’re filtering aggressive liquids)
Keep a close eye on temperature and exposure time when filtering solvents or corrosive blends
Food & Beverage
All standard CLARIBag media (Polypropylene felt, Polyester felt, Nylon mesh) are food compliant to EC 1935/2004
Nylon mesh for straining pulp, particles, or seeds
Felt for finer filtration (1–10 µm) before bottling or packaging
Never compromise on food-grade certification—full tracability and batch records are a must (which we provide as standard)
Examples of Relevant CLARIBag Products
75 micron Nylon monofilament mesh, Size 2 – Excellent for straining, general water/food use
10 micron Polypropylene felt, Size 2 – Popular for fine filtration, chemicals, water purification
50 micron Polypropylene felt, Size 4 - Suitable for small batch food or beverage filtration and side-stream water loops
Maintenance and Best Practice Tips
- Always install the correct size and collar type
- Inspect for integrity before use (no tears, sealed seams/collars)
- Monitor pressure drop and change at the recommended interval (normally 1 bar or when flow drops)
- Store bags in clean, dry conditions—our bags ship individually wrapped and batch traceable, perfect for regulated lines or allergy-sensitive products
- Review any abnormal downtime immediately (most failures relate to incorrect specification, overloading, or housing mismatch)
Let’s Get Practical: Streamlining Selection with Expert Help
At the end of the day, the right filter bag choice balances contaminant size, process type, compatibility, sizing, and operational needs. We’re engineers and operators ourselves—our goal is to help you go beyond guesswork for every application, whether you’re cleaning high-value process water, straining honey, or protecting chillers.
Trial new filter specifications at small scale whenever possible
Use our online selector tool for tailored recommendations in under a minute
Leverage technical support—we assist with sample requests, material certificates, and help you understand exactly what to expect in service
Remember bulk discounts and rapid shipment are available (see our terms)
Whether you’re specifying for a major plant or a craft operation, we’re here to help you get it right the first time—because when filtration is done well, nobody should even notice it’s there. If you need advice, don’t hesitate to contact the CLARIBag team or browse our full selection of filter bags and housings online.
