Bag Filters vs Cartridge Filters: Which Do You Need?
Buyers ask us this weekly, and the honest answer is a set of four numbers, not a brand preference: your flow rate, your solids load, your target micron rating, and your cost per change-out. Here is how each one points you to the right technology.
The short answer
Bag filters win when flow is high and solids are heavy. A single Size #2 bag handles up to 34 cubic metres per hour and holds between half a kilogram and three kilograms of solids before change-out. Cartridge filters win when the job is fine: ratings below 1 micron, final polishing, and low-solids duty where precision matters more than capacity. Many well-designed systems use both, bags first, cartridges after.
The comparison, number by number
| Criteria | ClaryFil Bag Filters | Cartridge Filters |
|---|---|---|
| Micron range | 1 to 300 micron | 0.1 to 50 micron |
| Flow rate per element | Up to 34 m3/hr (Size #2) | Typically 0.5 to 5 m3/hr |
| Solids-holding capacity | High: 0.5 to 3 kg per felt bag | Low: typically under 200 g |
| Cost per change-out | Low | Moderate to high |
| Reusability | Nylon mesh bags washable; felt bags single-use | Generally single-use |
| Filtration type | Depth (felt) or surface (mesh) | Depth, pleated, membrane |
| Best application | High-flow, high-solids process streams | Low-solids final polishing or fine filtration |
| Housing cost | Lower | Higher |
| Typical industries | Chemical, water treatment, oil and gas, desalination | Pharma, electronics, ultrapure water |
When the bag filter is right
Choose a bag filter when your stream carries visible solids, when flow rates would demand a wall of cartridges, or when change-out labour and disposal cost dominate your filtration budget. A high-solids stream that clogs a cartridge in hours can run a full shift on a felt bag, and the bag change takes minutes. For low-contamination duties at 50 micron and coarser, a washable nylon mesh bag cuts consumable spend further because it goes back into service after cleaning.
When the cartridge is right
Choose a cartridge when the target is finer than 1 micron, when you are polishing ahead of an RO membrane or a final filter, or when the process demands pleated or membrane media with an absolute rating. No bag reaches sub-micron territory; that is cartridge work by physics, not by preference.
The combination most plants actually need
The highest total cost we see in the field comes from plants running fine cartridges directly against dirty streams. The cartridge does the bag's job at ten times the consumable cost. The fix is staging: a ClaryFil felt bag takes the solids load first, and the cartridge behind it does the fine work it was priced for. Element life downstream typically extends several fold, and the arithmetic per year, not per piece, decides it.
Get a specification, not a guess
Send us your flow rate, fluid, solids description, and target micron rating. Our engineers will size the stages, quote the change-out interval, and put the annual numbers next to your current spend. Start with the ClaryFil filter bag range or go straight to a quote request.