High Flow Filter Cartridge Selection Guide: Flow & Micron Rating

INTRODUCTION

Selecting the right high flow filter cartridge is one of the most critical decisions when designing or upgrading an industrial filtration system. Flow rate and micron rating directly affect filtration efficiency, system stability, operating costs, and overall equipment lifespan. An incorrect choice may result in excessive pressure drop, premature cartridge replacement, or inadequate contaminant removal.

This High Flow Filter Cartridge Selection Guide: Flow & Micron Rating is designed to help engineers, project managers, procurement teams, and distributors clearly understand how to select the correct high flow filter cartridge for different industrial applications.
As a professional manufacturer and supplier, Econe Filtration provides high-performance high flow filter cartridges widely used in water treatment, RO pretreatment, power plants, petrochemical processing, food & beverage, and microelectronics industries.

This guide will explain:

What flow rate really means in high flow filtration
How micron rating affects filtration performance
The relationship between flow, micron rating, and pressure drop
How to choose the optimal combination for your system

What Is a High Flow Filter Cartridge?

A high flow filter cartridge is a large-diameter filtration element—typically 6 inches (152 mm)—designed to handle extremely high flow rates while maintaining stable filtration efficiency and low pressure drop.

Compared with traditional 2.5-inch or 4.5-inch cartridges, high flow cartridges offer:

Much higher flow per cartridge
Fewer cartridges per housing
Reduced housing size
Lower installation and maintenance costs

Typical high flow filter cartridges are available in lengths of 20”, 40”, and 60”, with flow capacities that can reach 70–110 m³/h per cartridge, depending on the micron rating and media design.

Why Flow Rate Matters in High Flow Filter Cartridge Selection

Understanding Flow Rate

Flow rate refers to the volume of liquid that passes through a filter cartridge within a given time, usually expressed as:

m³/h (cubic meters per hour)
GPM (gallons per minute)

In high flow filtration systems, flow rate is critical because these systems are often used in:

RO pretreatment
Desalination plants
Power plant cooling water
Industrial process water
Large-scale municipal water treatment

High Flow vs. Traditional Cartridge Systems

Filter Type	Typical Flow per Cartridge
2.5” Standard Cartridge	1–5 m³/h
4.5” Big Blue Cartridge	5–10 m³/h
High Flow Cartridge (6”)	70–110 m³/h

High flow filter cartridges drastically reduce the number of cartridges required, simplifying system design and reducing downtime during replacement.

Key Factors Affecting Flow Rate Performance

1. Cartridge Diameter and Length

The larger diameter of high flow cartridges provides a significantly larger filtration area. Longer cartridges (40” and 60”) naturally allow higher flow capacity than 20” cartridges.

2. Filtration Media Structure

Different media structures directly influence flow performance:

Pleated polypropylene (PP)
Glass fiber (GF)
Gradient density media

Optimized pleat geometry ensures uniform flow distribution and reduces localized pressure drop.

3. Contaminant Load

Higher suspended solids concentration leads to faster clogging, which reduces effective flow over time. This is why selecting the correct micron rating is just as important as flow capacity.

What Is Micron Rating in High Flow Filter Cartridges?

Micron Rating Explained

Micron rating defines the size of particles that a filter cartridge can remove.
One micron (µm) equals one-millionth of a meter.

Common micron ratings for high flow filter cartridges include:

1 µm
3 µm
5 µm
10 µm
20 µm
40 µm
70 µm
100 µm

Nominal vs. Absolute Micron Rating

Understanding the difference is essential:

Nominal rating: Removes a certain percentage (usually 60–90%) of particles at the stated size
Absolute rating: Removes ≥99.9% of particles at the stated size

For critical processes such as RO pretreatment or electronics water, absolute-rated high flow cartridges are strongly recommended.

How Micron Rating Affects Filtration Performance

Lower Micron Rating (1–5 µm)

Higher filtration accuracy
Better protection for downstream equipment
Higher initial pressure drop
Faster clogging if upstream contamination is high

Medium Micron Rating (10–20 µm)

Balanced filtration and flow
Common choice for industrial water treatment
Longer service life compared with finer filters

Higher Micron Rating (40–100 µm)

Very high flow capacity
Minimal pressure drop
Used for coarse filtration and pre-stage protection

Relationship Between Flow Rate and Micron Rating

Flow rate and micron rating are closely linked. In general:

Lower micron rating → lower flow rate → higher pressure drop
Higher micron rating → higher flow rate → lower pressure drop

Example Comparison

Micron Rating	Typical Flow Capacity	Pressure Drop
1 µm	Lower	Higher
5 µm	Medium	Medium
10 µm	High	Lower
40 µm	Very High	Very Low

This relationship explains why a single filtration system may use multiple stages of high flow cartridges with different micron ratings.

Common Applications and Recommended Flow & Micron Ratings

RO Pretreatment Systems

Typical micron rating: 5–10 µm
Purpose: Protect RO membranes from fouling
Balanced flow and accuracy

Seawater Desalination

Typical micron rating: 10–20 µm
High suspended solids tolerance
Long service life required

Power Plant Cooling Water

Typical micron rating: 20–40 µm
High flow demand
Stable operation over long periods

Food & Beverage Processing

Typical micron rating: 1–5 µm
High cleanliness requirements
Often absolute-rated filters

Why Correct Selection Reduces Total Filtration Cost

Choosing the right flow and micron rating combination:

Reduces cartridge replacement frequency
Minimizes pressure drop-related energy consumption
Protects downstream equipment
Improves system reliability

Many filtration failures are not caused by poor filter quality, but by incorrect selection.

Econe Filtration works closely with customers to analyze operating conditions and recommend the most cost-effective high flow filter cartridge configuration.

When to Use Multi-Stage High Flow Filtration

For systems with heavy contamination, a single micron rating may not be sufficient. Multi-stage filtration is often recommended:

First stage: 40–70 µm (coarse filtration)
Second stage: 10–20 µm (fine filtration)
Final stage: 1–5 µm (critical protection)

This approach extends cartridge life and improves overall system efficiency.