PP Melt-Blown Cartridge 9"3/4 - 5 Micron - DIMM

9"3/4 polypropylene melt-blown cartridge - 5 micron

Sediment filter cartridge in pure polypropylene, 9"3/4 long (European standard format), 5 micron rating, FR-E version. DIMM reference KM-A4261110.

9"3/4 is the size of standard filter housings on the European market, not to be confused with the slightly longer Anglo-Saxon 10". Check your housing format before ordering.

The melt-blown process

Melt-blown extrudes molten polypropylene fibres and blows them continuously around a core, where they bond together as they cool.

The result is a media in one piece: no binder, no additives, no adhesive. Nothing can therefore migrate into the filtered water, a point that matters when the cartridge treats water intended for consumption.

Against a string-wound cartridge, whose structure is a wound yarn, melt-blown forms a dense web of microfibres. At equivalent rating it gives more consistent retention and a lower initial pressure drop.

Depth filtration

Media density is not uniform: it increases inwards. Coarse particles are stopped in the more open outer layers; fines travel further before being retained.

The cartridge therefore uses its whole volume instead of blinding on its outer face alone. At identical rating this means higher dirt-holding capacity and longer service life than a surface media.

Why 5 micron

5 micron is the polishing rating of mechanical filtration. It captures fine sand, rust, clay particles and pipe deposits that a coarse rating lets through.

It is the rating fitted immediately before the equipment being protected. Upstream of an RO system, it stops the membrane fouling mechanically. Upstream of a UV lamp, it removes the turbidity that would cut the effectiveness of the radiation. Protecting a softener, it prevents sediment fouling the resin bed and degrading regenerations.

On loaded water it is better placed downstream of a coarser prefilter (20 or 25 µm): a fine rating saturates quickly if it absorbs the whole load on its own.

Where to use it

As fine filtration in a 9"3/4 housing, as RO prefiltration, protecting a softener or a treatment train, ahead of a UV lamp, and on well or borehole installations as a second stage.

Replacement

Replacement is judged on pressure drop, not on the calendar. A noticeable drop in flow, or a rising differential pressure across the filter, signals a saturated cartridge. In practice, count on 3 to 6 months depending on water quality.

A cartridge left in place beyond that does more than throttle the installation's flow: under pressure it can release part of the particles it had captured.

Fitting

Shut off the water and depressurise before opening the housing. On reassembly, grease the bowl O-ring with food-grade silicone grease and check that it is clean, correctly seated and untwisted: this is the first cause of leaks. After repressurising, flush for a few minutes before use.