Category · Equipment
Water Filtration Systems
The first barrier in every treatment train — and the cheapest insurance in the plant. Get this stage wrong and every stage after it fails early.
Media beds · PSF · ACF
Raw & ETP water
SDI / TSS reduction
Backwashable
Media filtration works by depth, not by chemistry. Water is pushed down through a graded bed — fine media on top doing the work, heavier media below holding the bed in place — and what the water is carrying stays behind in the voids between the grains.
Two systems make up the category, and they are almost always bought as a pair: sand takes out what you can see, carbon takes out what you can smell. Between them they set the fouling load every membrane and resin bed downstream will have to live with.
Service Flow Rate
2.5 – 75
m³/hr per vessel
Systems In Category
2
bought as a pair
Backwash Trigger
0.5 – 0.7
bar differential
Where This Category Sits
Filtration stages highlighted
Filtration sits at the very front — everything downstream is specified on the assumption that these two vessels are doing their job.
The Shared Mechanism
Filter → load up → backwash
Both systems in the category run the same four-stage cycle. Where a resin bed is regenerated with chemicals, a media bed is simply washed backwards with its own water.
STEP 01
Distribution
Feed strikes an entry distributor that splays the water evenly across the full bed area — uneven flow channels, and a channelled bed filters nothing.
STEP 02
Filtration
Solids are retained in the voids of the fine top media; heavier graded layers below support the bed and keep it from compacting.
STEP 03
Saturation
As load accumulates the bed chokes. Either flow drops away or TSS starts appearing in the product line — the differential pressure rises either way.
STEP 04
Backwash
Flow is reversed to lift and scour the bed, carrying retained solids to drain. No chemicals, no neutralisation — just water and a few minutes.
Exception
Carbon does not filter — it adsorbs.
Sand traps particles mechanically, so a backwash returns the bed to new. Activated carbon holds dissolved molecules on its surface instead, and that surface is consumed — backwashing clears the solids but not the loading. Carbon is a media replacement item on a fixed interval, typically every 12 to 24 months, and chlorine breakthrough is the signal you have left it too long.
Two Filters, One Skid
Both systems in the category
Sand first, carbon second — sand protects the carbon from a solids load that would blind it, and carbon protects everything after. They are specified, skidded and controlled as one unit.
PSF
Lead Product
Pressure Sand Filter
Graded media bed · depth filtration
Removes
Suspended solids
Silt & clay
Grit
Turbidity
Algae & microbes
Fine sand on top does the filtration; heavier sand or anthracite below supports it. Sized on surface loading rate rather than volume — which is why a taller vessel does not buy you more throughput.
ACF
Core Product
Activated Carbon Filter
Adsorption · dechlorination duty
Removes
Chlorine
Odour
Colour
Organic matter
Oil & grease*
Activated carbon adsorbs dissolved organics, free chlorine, colour and foul smell, and reduces oil and grease to a limited extent. Mandatory ahead of any polyamide RO membrane — chlorine oxidises the film irreversibly.
Primary Reduction
SDI
TSS
Turbidity
Free chlorine
Organic matter
Odour
Colour
Oil & grease
Tank Configurations
Service flow 2.5 – 75 m³/hr
Both PSF and ACF are offered in the same three vessel materials. The internals and control philosophy do not change — the choice is driven by water chemistry, hygiene requirement and site life expectancy.
Configuration A
Mild Steel
The default for utility duty and larger flows where cost per m³ governs.
Service Flow
2.5 – 75 m³/hr
Design Pressure
3.5 – 6 bar
Features
-
✓
Epoxy-coated MS tanks
-
✓
Diaphragm and butterfly valve sets
-
✓
PLC control with auto backwash sequence
-
✓
Differential pressure gauge across the bed
-
✓
Sized to flow and TSS load, not catalogue size
Configuration B
Stainless Steel
For hygienic duty, aggressive feed chemistry or long design life.
Service Flow
2.5 – 75 m³/hr
Design Pressure
6 – 10 bar
Features
-
✓
SS304 / SS316L tanks
-
✓
Diaphragm and butterfly valve sets
-
✓
PLC control with auto backwash sequence
-
✓
Differential pressure gauge across the bed
-
✓
Sized to flow and TSS load, not catalogue size
Configuration C
FRP
For small and mid flows, corrosive water and skid-mounted plants.
Service Flow
2.5 – 75 m³/hr
Design Pressure
2.5 – 6 bar
Features
-
✓
FRP tanks, corrosion-free
-
✓
Diaphragm and butterfly valve sets
-
✓
PLC control with auto backwash sequence
-
✓
Differential pressure gauge across the bed
-
✓
Sized to flow and TSS load, not catalogue size
Common media: fine sand, anthracite and activated carbon · backwash initiation monitored by differential pressure gauge · also recovers suspended-solid-laden ETP water for reuse.
Selection Matrix
Particles → dissolved organics
In practice the answer is usually both, in series. The matrix matters when you are diagnosing which of the two is underperforming.
Parameter
ACF
Activated Carbon Filter
Mechanism
Depth filtration —
mechanical capture
Adsorption —
surface chemistry
Media
Graded fine sand
+ anthracite support
Granular activated
carbon
Removes
Suspended solids,
turbidity, silt, grit
Chlorine, organics,
colour, odour
Restored by
Backwash —
full recovery
Backwash clears solids;
loading is permanent
Media life
5 – 8 years
(top-up as lost)
12 – 24 months
(replacement)
Position
First vessel
in the train
Immediately
after PSF
Protects
ACF bed from
blinding
RO / NF membranes,
resin beds, UV quartz
Failure signal
Turbidity or SDI
rising downstream
Free chlorine detected
at RO inlet
Figures are indicative design ranges — final selection follows a feed water analysis.
Reference Installations
Client names withheld under confidentiality. Full commissioning data available on request.
Pharmaceutical · Formulations
Dual-stream PSF + ACF ahead of a PW plant
Formulations site, Gujarat. Duty / standby media trains on the utility inlet feeding a double-pass RO and EDI block — free chlorine held at non-detect at the membrane inlet.
Textile · Processing
ETP water recovery through media filtration
Processing house, Tamil Nadu. Media filters on treated effluent, recovering suspended-solid-laden ETP water back to the dyehouse make-up line instead of discharging it.
Food & Beverage
FRP media skid on a bottling line
Beverage plant, Maharashtra. Compact FRP PSF and ACF skid on the borewell inlet, taking out grit and odour ahead of softening and RO for the syrup room.