What is the Typical Pore Size Range Available for Sintered PE Filters?

Introduction

When industries require precise and reliable filtration, the choice of filter material and pore size becomes a critical factor. From water treatment facilities to pneumatic systems and chemical processing, the filtration medium directly affects product quality, system efficiency, and operational cost.

Among the many filter media available, sintered polyethylene (PE) filters are widely recognized for their cost-effectiveness, chemical resistance, and customizable porosity. These filters are produced through a sintering process that creates a porous structure capable of filtering particles ranging from coarse debris to fine sediments.

In this detailed guide, we will examine the typical pore size range for sintered PE filters, explain the difference between absolute vs nominal ratings, and provide selection guidelines for different industrial applications.

1. Understanding Sintered PE Filters

What is a Sintered PE Filter?

Sintered polyethylene (PE) filters are manufactured using powder metallurgy technology. High-density polyethylene (HDPE) or ultra-high-molecular-weight polyethylene (UHMW-PE) powders are compressed and heated below their melting point, causing the particles to bond together while leaving interconnected pores.

The result is a rigid, durable, and porous structure that allows fluids and gases to pass through while trapping unwanted particles. Because of their structure, sintered PE filters are highly effective in removing particulates, enabling aeration, and ensuring consistent flow performance.

Why Choose Sintered PE Filters?

• Cost-effective: Lowest price compared to metallic sintered filters (bronze or stainless steel).

• Chemical resistance: Excellent resistance to most dilute acids and alkalis.

• Lightweight: Easier to install and replace compared to heavy metallic filters.

• Customizable porosity: Pore size can be tailored from 2 µm up to 150 µm depending on application.

• Reusability: Can be cleaned and reused multiple times, reducing replacement costs.

2. Typical Pore Size Range

DALON’s sintered PE filters are standardized to cover the most common industrial filtration needs.

Standard Pore Size Range

• Minimum: 5 µm

• Maximum: 100 µm

This range provides flexibility, covering both fine and coarse filtration requirements.

Common Standard Sizes

• 5 µm (Absolute): High-efficiency filtration, suitable for removing very fine particles.

• 10 µm (Absolute): Effective for polishing applications and membrane pre-filtration.

• 20 µm (Nominal): General industrial filtration and protection of equipment.

• 40 µm (Nominal): Balance of flow rate and particle retention.

• 70 µm (Nominal): Coarse filtration for larger particles.

• 100 µm (Nominal): Pre-filtration or protection in systems with high particulate loads.

3. Absolute vs Nominal Pore Size Ratings

What is an Absolute Rating?

• Definition: The filter retains at least 99% of particles at the stated pore size.

• Example: A 5 µm absolute sintered PE filter ensures that nearly all particles larger than 5 µm are removed.

• Applications: Used in critical processes such as pharmaceuticals, food and beverage filtration, and final polishing of water.

What is a Nominal Rating?

• Definition: Indicates approximate particle retention (typically 85–95% at the stated pore size).

• Example: A 40 µm nominal filter may allow a small percentage of 40 µm particles to pass through.

• Applications: Ideal for pre-filtration, coarse filtration, and non-critical systems where full particle retention is not mandatory.

4. Performance Characteristics by Pore Size

Pore size directly impacts both filtration efficiency and flow rate. The smaller the pore, the higher the retention efficiency, but the lower the flow rate.

Note: Performance values vary with fluid viscosity, temperature, and filter geometry. Testing according to ASTM F316 is recommended for accurate verification.

5. Temperature and Pressure Considerations for PE Filters

While pore size defines filtration efficiency, temperature and pressure limits determine whether a PE filter is suitable for your process.

Temperature Ratings

• Continuous Use: –40 °C to 80 °C (176 °F)

• Short-Term Peak: up to 90 °C (194 °F) for ≤1 hour

• Caution: Prolonged use above 80 °C can lead to softening, deformation, and reduced pore stability.

Pressure Ratings

• Maximum Operating Pressure at 20 °C: 5 bar (72 psi)

• At 60 °C: ≤ 3 bar (43 psi)

• At 80 °C: ≤ 2 bar (29 psi)

• Burst Pressure (Room Temp): ≥ 10 bar (145 psi) with proper housing support

6. Customization Options

While standard pore sizes (5–100 µm) meet most industrial needs, customized solutions are available for specialized requirements.

• Tighter Pore Tolerances:

  • Down to 2 µm for fine pre-filtration in laboratory or pharmaceutical applications.

  • Lower flow rates expected due to higher resistance.

• Graded Porosity:

  • Multi-layer sintered PE filters can be manufactured with progressively finer pores.

  • Increases dirt-holding capacity and extends filter life.

• Shape and Size Customization:

  • Available as discs, tubes, cones, cartridges, and custom geometries.

  • Dimensions follow the ID × OD × Length standard for plain bushings or ID × OD × Flange OD × Flange Thickness × Total Length for flanged bushings.

7. Comparing PE with Bronze and Stainless Steel for Pore Size

Sintered Bronze Filters

• Pore Size Range: Typically 5–100 µm

• Rating: Usually nominal filtration

• Advantages: Higher mechanical strength, better for moderate temperature & pressure

• Limitations: Corrosion issues in acidic environments

Sintered Stainless Steel Filters (316L)

• Pore Size Range: 0.5–150 µm

• Rating: Precise, stable pore structures, often tested by bubble point method (ASTM F316)

• Advantages: Excellent for high-temperature, high-pressure, and corrosive environments

• Limitations: Higher cost compared to PE and bronze

Comparative Summary

• PE Filters: Best for low-cost, mild acidic/alkaline water, lower temperature and pressure.

• Bronze Filters: Moderate cost, but limited chemical resistance; suitable only for non-corrosive fluids.

• Stainless Steel Filters: High upfront cost, but superior pore stability across a wide range of conditions.

8. Selection Guide: Pore Size by Application

9. Key Considerations for Buyers

1. Match pore size with particle size distribution in your water system.

2. Factor in temperature and pressure derating—do not exceed 80 °C or 5 bar (2–3 bar at elevated temperatures).

3. Avoid hydrocarbons and oxidizing acids, as they damage PE filters.

4. Validate filter performance with bubble point testing (ASTM F316).

5. Plan for regular maintenance with backflushing or mild solvent cleaning.

Conclusion

The typical pore size range of sintered PE filters is 5–100 µm, with absolute ratings at 5–10 µm for fine filtration and nominal ratings at 20–100 µm for general or coarse applications.

For slightly acidic water environments (pH 4–6), sintered PE filters are a highly cost-effective choice—provided that operating temperatures remain below 80 °C and pressures do not exceed 5 bar. They deliver excellent chemical resistance to dilute acids and alkalis, low cost, and easy cleanability, making them suitable for wastewater pretreatment, irrigation, compressed air systems, and laboratory applications.

For higher pressure or more corrosive environments, sintered stainless steel 316L filters are recommended due to their extended service life, mechanical strength, and resistance to harsh chemicals.

At DALON, we manufacture and customize sintered PE filters in a wide range of pore sizes (5–100 µm standard, down to 2 µm on request), dimensions, and shapes. Whether you need discs, tubes, cartridges, or bushings, our engineering team will help you find the most cost-effective and reliable filtration solution for your industry.

👉 Explore DALON Sintered PE Filters – Request a Custom Quote Today

FAQ

1. What is the typical pore size range of sintered PE filters?
The standard range is 5–100 µm, with custom options down to 2 µm for specialized applications.

2. What’s the difference between absolute and nominal pore size?

• Absolute rating means >99% of particles above the stated size are removed.

• Nominal rating means 85–95% of particles at that size are removed.

3. Can I use sintered PE filters for hot water?
Yes, but only up to 80 °C (176 °F) continuously. Short-term peaks of 90 °C (194 °F) are possible but should not be repeated often.

4. What is the maximum operating pressure for sintered PE filters?

• 5 bar (72 psi) at 20 °C (68 °F)

• 3 bar (43 psi) at 60 °C (140 °F)

• 2 bar (29 psi) at 80 °C (176 °F)

5. Are sintered PE filters resistant to acidic water?
Yes, they have excellent resistance to dilute acids and alkalis (pH 2–12), making them suitable for mildly acidic water applications.

6. How do pore sizes affect flow rate?

• Smaller pores (5–10 µm) provide finer filtration but lower flow rates.

• Larger pores (40–100 µm) allow higher flow rates but less fine filtration.

7. Can I order custom pore sizes?
Yes, custom sintered PE filters can be manufactured with pore sizes as small as 2 µm or as large as 150 µm, depending on your needs.

8. How should I clean PE filters?
Use backflushing with water or mild solvents (like isopropyl alcohol). Avoid steam cleaning, high-pressure jets, or aggressive chemicals like hydrocarbons and halogenated solvents.

9. Which industries commonly use sintered PE filters?

• Water treatment and wastewater plants

• Agriculture & irrigation systems

• Pneumatic equipment and air silencers

• Pharmaceutical and laboratory pre-filtration