Equipment Comparison · November 13, 2026
Walk into any water treatment plant and you will find at least two of the three main filter cartridge families on the skid. Walk into an enquiry inbox and you will find buyers using the word "cartridge filter" for all of them - then being quoted the wrong one.
The three families are not interchangeable. They differ in how they hold dirt, how fine they filter, how hot they can run, and whether you can wash and reuse them. Pick by duty, not by price tag, and the cartridge budget usually drops while change-out intervals get longer. This guide compares the three families and ends with a decision table by duty and a purchase-order checklist.
| Family | Filtration style | Typical micron range | Max temperature | Reusable? |
|---|---|---|---|---|
| PP melt blown | Depth - graded density, dirt held through the wall | 1-60 um | ~60 C | No, replace |
| Pleated (PP / PES membrane) | Surface - large pleated area, absolute rated | 0.2-70 um | ~80 C (membrane dependent) | Occasionally rinse, usually replace |
| Sintered stainless steel | Depth - sintered powder, uniform tortuous pores | 1-100 um | 400 C+ | Yes - backwash / ultrasonic clean |
A melt blown cartridge is polypropylene spun into a graded-density wall: coarse pores outside, fine pores inside. Dirt stacks through the depth, so dirt-holding capacity per euro is excellent. That is exactly what you want ahead of an RO membrane: catch the bulk of the sediment cheaply, replace the element when the pressure drop reaches 1.0-1.5 bar, and never feel bad about throwing it away.
Where it struggles: above about 60 C the polypropylene softens; aggressive solvents attack it; and as a nominally rated element it is not the tool for sterile filtration. Cost per element is low, so running cost stays low - but you keep buying consumables forever.
See our PP melt blown filter cartridges for standard sizes and micron ratings.
A pleated cartridge folds a large filtration area into a standard-size element - several times the area of the same-length melt blown cartridge. The practical result: lower pressure drop at the same flow, more litres before it clogs, and (when pleated with a membrane) an absolute rating you can state on a datasheet and hold accountable.
Pleated media are the right choice when the job is polishing or protecting: final filtration before filling, protecting a UV system, guarding a precision stage, or any duty where a nominal rating is not good enough. They cost more per element than melt blown, but the large area often wins on cost per litre in continuous duty.
For high-flow versions of the same idea, see the guide on when to use 40-inch high flow cartridges; our pleated filter elements cover the standard-housing sizes.
A sintered SS cartridge is stainless powder pressed and sintered into a porous metal wall. Three properties separate it from everything polymer-based:
The trade-offs: higher purchase price, and a nominal micron floor around 1 um - finer than that, go to a membrane pleated cartridge. For pharma and food duty the housing matters as much as the element; our SS304 vs SS316L selection guide covers that decision. See the sintered SS filter cartridge product page for sizes and ratings.
| Criterion | PP melt blown | Pleated | Sintered SS |
|---|---|---|---|
| Dirt holding per unit cost | Excellent | Very good (large area) | Good |
| Rating type | Nominal | Nominal or absolute | Nominal, tight tolerance |
| Fine end | ~1 um | 0.2 um | ~1 um |
| Temperature limit | 60 C | 80 C typical | 400 C+ |
| Solvent / chemical duty | Poor | Media dependent | Excellent |
| Cleaning / reuse | No | Limited | Yes, repeatedly |
| Running cost (continuous) | Low upfront, ongoing | Medium | High upfront, near zero after |
| Typical lifetime | Weeks to months | Months | Years |
| Duty | Recommendation | Why |
|---|---|---|
| RO pretreatment, sediment before the membrane | PP melt blown, 5 um then 1 um in series | Cheap depth filtration, simple change-out |
| Polishing before filling, packaging or UV | Pleated, absolute rated | Stated, auditable micron rating |
| Steam line, hot condensate, solvent duty | Sintered SS | Only family that survives the temperature |
| High change-out cost or remote site | Sintered SS | Clean in place, no consumable logistics |
| Food / pharma process water | Pleated membrane or sintered SS316L | Sanitary housing plus cleanable element |
| High flow above ~40 m3/h in one housing | Pleated high flow (40 inch) | One element replaces dozens of standard ones |
| Coarse protection of pumps and valves | PP melt blown 20-60 um | Lowest cost protection |
On a typical 20 m3/h RO plant the sequence is: multimedia or FRP filter vessels for bulk turbidity, then a precision (security) filter housing with a 5 um PP melt blown cartridge guarding the high-pressure pump, with a 1 um cartridge in front of the dosing points where antiscalant is added. Downstream, pleated absolute cartridges polish the permeate for the end use, and sintered SS elements appear wherever steam, hot CIP solution or aggressive chemistry flows. Each family does the job the others do badly - which is why we quote them as a set rather than a substitution.
The housing decision (single vs multi, flow per housing, material) is covered in our bag filter vs cartridge filter guide; micron selection logic for the consumable side is the same as in our filter bag micron rating guide.
We manufacture the housings and supply all three cartridge families, so our recommendation is duty-driven rather than catalogue-driven: PP melt blown elements for economical depth filtration, pleated elements for absolute-rated polishing, sintered SS cartridges for reusable and extreme duty, and the matching precision filter housings in SS304 or SS316L. For single-housing flows above ~40 m3/h, see the high flow filtration range and our 40 inch high flow cartridges.
Send us the flow, the feed water analysis and the change-out interval you can live with, and we will come back with the element and housing combination we would run in your position - including the running-cost comparison between disposable and reusable options.
Related products: PP melt blown filter cartridges · large flux pleated filter elements · sintered SS filter cartridges · precision cartridge filter housings
