Why CTA Three-Stage Filtration Matters

In industrial compressed air systems, clean, dry, and oil-free air is critical for protecting downstream equipment and ensuring product quality. The CTA (Coalescing + Treatment + Adsorption) three-stage filter system is the industry standard for removing contaminants, with the A-grade activated carbon filter as the final stage that eliminates vapors and odors.

A frequent question from global clients is:
👉 Should the third-stage filter cartridge be replaced every 4000 hours or 8000 hours?
This guide helps you optimize maintenance, reduce cost, and ensure uncompromising compressed air purity.

4000 Hours vs 8000 Hours: What’s the Right Interval?

• 4000 hours (≈1 year): A conservative, safety-first guideline. Guarantees air purity for sensitive industries like food & beverage, pharmaceuticals, and electronics.

• 8000 hours (≈2 years): Possible only under ideal conditions: clean intake air, effective pre-filters, low oil vapor content, and stable operating temperatures.

📌 Key Point: Don’t rely only on time. The real filter life depends on your operating environment.

How the CTA Three-Stage Filter System Works

1. Coalescing Filter (C-Stage): Removes bulk water and oil aerosols.

2. Particulate Filter (T-Stage): Captures solid particles down to micron size.

3. Activated Carbon Filter (A-Stage): Adsorbs residual oil vapors and odors.

   • Once saturated, the A-stage filter cannot trap oil vapors—risking product contamination and equipment damage.

3 Methods to Determine Optimal Filter Replacement

1. Monitor Differential Pressure (ΔP)

• All housings include a ΔP gauge.

• As filters load with contaminants, ΔP rises.

• Action: Replace when ΔP reaches 0.7–1.0 bar to prevent energy waste and failure.

2. Test Downstream Air Quality

• Use oil vapor test kits or analyzers.

• Action: Replace immediately if oil vapor approaches ISO 8573-1 limits (Class 0 or Class 1).

3. Track with Maintenance Logs

• Record hours, conditions, and ΔP at each inspection.

• Result: Build a customized, cost-effective replacement cycle for your facility.

Best Practice Recommendations

• Use 4000 hours as a safe baseline.

• Let the differential pressure gauge be your main replacement guide.

• Validate with air quality tests for ISO 8573-1 compliance.

Why Choose Us as Your Filtration Partner?

• Expert Guidance: Technical advice tailored to your application.

• Premium CTA Filter Cartridges: Long service life, reliable ISO 8573-1 purity, low energy consumption.

• Cost-Effective Procurement: Standard and custom solutions with competitive pricing.

Call to Action

Ready to maximize compressed air purity while saving costs?
👉 [Contact Us Today for a Free Consultation & Quotation] – Let our experts provide the right CTA three-stage filter cartridge solution for your system.