Utility Filtration in Process Industries: Cartridge Filter & Micron Rating Guide

Written by David Keay | Jan 19, 2026

Utility filtration works best when it is engineered as a system, not chosen in isolation. Correct cartridge type and micron rating are essential to balance protection, performance, and operating cost.

The tables below provide typical guidance, not absolute rules. Final selection should always consider fluid quality, contamination load, flow rate, temperature, and downstream sensitivity, but these are an excellent starting point.

Utility Type vs Cartridge Filter Selection

Utility	Primary Contaminants	Recommended Cartridge Type(s)	Purpose
Process water (general)	Sand, rust, scale, silt	Depth → Pleated	Equipment protection
Rinse water (F&B)	Fine particulates, microbes	Pleated → Membrane	Hygiene and quality
Boiler feed water	Sediment, corrosion products	Depth → Pleated	Protect boilers & valves
Cooling water	Solids, debris	Depth cartridges	Prevent fouling
CIP solutions	Undissolved solids	Pleated cartridges	Nozzle protection
Compressed air	Particles, oil aerosols, moisture	Pleated → Coalescing	Instrument protection
Process gases	Particles, microbes	PTFE membrane	Sterility
Steam	Rust, scale	Sintered metal or PTFE	Valve & process protection
Chemical utilities	Particulates, gels	Depth or pleated (chemical compatible)	Product integrity

Typical Micron Rating Recommendations by Utility

Utility Application	Typical Micron Rating	Rating Type
Raw process water	10–50 µm	Nominal
Pre-filtration for membranes	1–5 µm	Absolute
Final process water	0.2–1 µm	Absolute
Boiler feed water	5–10 µm	Absolute
Cooling water	25–100 µm	Nominal
CIP return lines	5–25 µm	Nominal
Compressed air (particle)	1–5 µm	Absolute
Sterile air/gas	0.2 µm	Absolute
Steam filtration	1–5 µm	Absolute

As utilities become more critical to product quality, filtration shifts from nominal depth filtration to absolute-rated pleated or membrane cartridges.

Depth vs Pleated vs Membrane – When to Use Each

Cartridge Type	Best Used When	Typical Micron Range	Notes
Depth	High dirt load, variable quality	1–100 µm	High capacity, cost-effective
Pleated	Stable systems, high flow	0.2–50 µm	Low pressure drop
Membrane	Hygiene or sterility required	0.1–0.45 µm	Testable & validatable

Water Utility Filtration – Example Staged Design

Stage	Cartridge Type	Micron Rating	Function
Stage 1	Depth (melt blown)	20 µm nominal	Bulk solids removal
Stage 2	Pleated polypropylene	5 µm absolute	Fine particulate control
Stage 3	PES membrane	0.2 µm absolute	Microbial control

This approach:

Extends service life of fine cartridges
Reduces pressure drop spikes
Improves consistency of downstream processes

Compressed Air & Gas Utility Filtration

Application	Cartridge Type	Micron Rating	Function
Plant air (general)	Pleated	5 µm	Particle removal
Instrument air	Pleated	1 µm	Protect valves & actuators
Oil-sensitive systems	Coalescing	0.01–0.3 µm	Oil aerosol removal
Sterile air/gas	PTFE membrane	0.2 µm	Bacteria retention
Tank venting	Hydrophobic PTFE	0.2 µm	Sterile pressure equalisation

Carbon Cartridge Selection for Utility Water

Application	Carbon Type	Typical Pre-Filtration	Notes
Dechlorination	Carbon block	5 µm pleated	Best chlorine removal
Taste & odour	GAC	10 µm depth	Lower pressure drop
RO membrane protection	Carbon block	1–5 µm absolute	Protects membranes
Ozone removal	Carbon block	1–5 µm	Rapid adsorption

Important:
Carbon cartridges must always be protected with upstream particulate filtration to prevent premature fouling.

Practical Micron Selection Rules of Thumb

Protect equipment: 5–25 µm
Protect membranes: ≤5 µm absolute
Protect hygiene:2 µm membrane
High dirt load: Use depth first
High flow & clean fluids: Use pleated

Micron rating alone is not enough – rating type (nominal vs absolute) and media construction are equally important.

Final Thoughts

Utility filtration is often under-specified because it is “not the product.” In reality, utilities define:

Process stability
Equipment life
Hygiene and compliance
Overall operating cost

Cartridge filters provide a modular, scalable way to control utility quality – if selected correctly. If you have any questions on filtration solutions for utilities in your industrial processes then you can give us a call or send us an email - we’d be more than happy to help.

You can also read more:

Membrane Vs Depth Filtration in MicroFiltration: A Technical Comparison
A Guide to Selecting the Right Micron Rating
Ensuring You Use The Optimum Sterile Gas Filter
Understanding Absolute vs Nominal Ratings in Depth Cartridge Filters
And you can also read more about some of the utility applications: Steam, Sterile Gas, Sterile Venting & one of the most common utilities, Industrial Water.

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