How the calculation works
- Design flow per cartridge: about 1 m³/h per inch of length for ratings of 20 µm and coarser – 20 m³/h for 20 inch, 40 m³/h for 40 inch and 60 m³/h for 60 inch cartridges.
- Finer ratings lower the design flow: factor 0.9 at 10 µm, 0.8 at 5 µm and 0.6 at 1 µm.
- Cartridges required = flow × (1 + design reserve) ÷ design flow per cartridge, rounded up.
Why not run at the maximum flow?
Manufacturers state maximum flows of 70–110 m³/h for 40 and 60 inch cartridges in clean water. At a lower design flow the pressure drop is lower and the cartridge holds more dirt before it has to be changed. For reverse osmosis pre-filtration and other continuous duties, a conservative design flow pays back through longer cartridge life.
Limits of this calculator
The calculator assumes water-like liquids at ambient temperature and a normal solids load. Viscous liquids, high solids loads or a very low permitted pressure drop need more cartridges. Details on media, sizes and housings are on the page for high flow filter cartridges and in our selection and sizing guide.
Frequently asked questions
How much flow can one high flow cartridge handle?
A 6-inch diameter cartridge can pass up to about 70 m³/h at 40 inch and 110 m³/h at 60 inch length in clean water. For continuous operation, 40 and 60 m³/h are common design values.
How many standard cartridges does one high flow cartridge replace?
One 40 inch high flow cartridge handles roughly the flow of 10–20 standard cartridges of 40 inch length and 2.5 inch diameter, in a much smaller housing.
When should high flow cartridges be changed?
When the pressure drop reaches the limit stated by the manufacturer, typically 2.4 bar, or earlier if the downstream process requires it.