FRL: A 5-Minute Illustrated Selection Guide

After reading "Working Principle" and "Internal Structure," you should now have a solid understanding of air treatment units. It’s time to move beyond theoretical exploration and consider a more practical question: How do you select the right air treatment unit for your needs?

You might be confused by the various parameters of air treatment units or overwhelmed by the numerous brands and models available, such as those from FESTO or SMC. Don’t worry. This article will guide you through the selection process by covering key parameters, brand characteristics, and how to evaluate the quality of different units.

Key Parameters of FRL

Flow Rate:

Flow rate is the most critical parameter of an air treatment unit and is common to air filters, regulators, and lubricators. You need to estimate the total maximum air consumption of all downstream pneumatic systems and then select a model with a CV value slightly higher than that estimate. Insufficient flow may lead to inadequate pressure in downstream equipment, resulting in poor performance.

Typically, larger units of the same model offer higher flow rates. For example, in the Fescolo series, AC4010 > AC3010 > AC2010.

Filtration Precision:

This determines the purity of the filtered air and is usually defined by the filter element's rating. In pneumatic systems, filtration precision typically ranges from 40μm to 5μm, depending on the application.

Note that higher filtration precision is not always better, as it can reduce flow, increase pressure drop, and cause efficiency losses. For instance, certain pneumatic triplex units from Fokca exhibit different flow rates when using filter elements of different precision levels.

Working Pressure:

Working pressure refers to the pressure tolerance of the air treatment unit and sets the maximum pressure limit for downstream equipment.

Exceeding this limit can accelerate seal wear, reduce the FRL's service life, increase noise, and cause operational instability.

If the proof pressure is exceeded, the unit may operate unpredictably. Prolonged overpressure use can cause fragile components such as water bowls or oil sight glasses to rupture, endangering the entire pneumatic system.

Common pressure conversions: 1 MPa = 10 bar = 145 psi ≈ 1 kgf/cm²

Installation Method:

Compressed air typically flows in and out of the unit through tubing and fittings. If the tube diameter or fittings are incompatible with the unit's size, the system's flow and working pressure may be restricted, or installation may become impossible. Choosing appropriate mounting brackets can help avoid additional installation challenges.

Size:

Larger models generally offer higher flow rates but come with increased costs. Their larger size may also pose installation difficulties, so practical considerations should guide your choice.

Characteristics of Different Brands

◆  Festo: Sleek and aesthetically pleasing design, smooth and precise pressure regulation, typically made of zinc alloy with good pressure resistance, and aluminum alloy options available.

◆ SMC: Relatively higher flow rates, wide applicability, and aluminum alloy construction (e.g., AD12 series).

◆ Airtac: Fully plastic construction, offering good cost-effectiveness.

How to Evaluate the Quality of an Air Treatment Unit?

With hundreds of air treatment units on the market, how can you determine whether a unit is good or not? What details should you pay attention to when purchasing one to ensure a better user experience?

First, consider the valve body material. Generally, zinc alloy offers higher pressure resistance than aluminum alloy, and aluminum alloy outperforms plastic materials. Fescolo's air treatment units, for example, are made using a leak-proof die-casting process, which prevents micro-leaks that are undetectable in standard water tests. This ensures minimal pressure loss even in high-pressure environments.

The material of the water bowl and oil bowl is also critical to the unit's pressure resistance. Low-quality bowls may rupture during use, with flying fragments and sudden pressure loss posing risks to both equipment and personnel.

Fescolo uses high-quality PC material, which offers high elasticity, a wide temperature tolerance, excellent fatigue resistance, and superior electrical insulation. Its high transparency allows users to clearly observe the bowl's contents, making it easier to determine when to drain water or add oil.

Next, examine the filter element material. Fescolo's air treatment units use copper or fiber filter elements. Copper filter elements are heat-resistant, corrosion-resistant, and reusable after cleaning. Compared to ordinary plastic filter elements, fiber filter elements are harder, provide better filtration, and are less prone to becoming brittle or cracking over time.

For example, Fescolo utilizes custom-made high-precision screws(right side), which enable finer and more accurate pressure regulation. Fully automated precision machining and surface treatment processes enhance both aesthetics and resistance to corrosion and wear.

The regulating spring is a key component of the air regulator, directly affecting adjustment accuracy, stability, and service life. Therefore, using high-strength, fatigue-resistant springs is essential. In applications requiring high-precision adjustments, springs must be manufactured with strict tolerances to ensure accurate pressure regulation.

As well as some other non-core features that can impact the user experience. For example, whether the adjusting knob has anti-slip texture and a locking mechanism; whether the lubricator allows for easy oil refilling; and whether the oil flow regulation is precise, among others.

Fokca（Fescolo）is a professional pneumatic cylinder manufacturer and supplier. As a leading Chinese supplier in this field, we specialize in providing high-quality, precision-engineered cylinders designed for a variety of applications.

As a manufacturer, we guarantee quality from raw materials by selecting premium aluminum/zinc alloys. Each valve body undergoes leak-proof die-casting, fully automated precision machining with strict tolerance control, surface treatment, and multiple automated quality inspections including pressure and airtightness tests to ensure every product meets standards.

Please feel free to visit our air treatment unit product page for more information. Additionally, you can explore our Blog, where we provide a range of resources including videos, images, articles, and drawings to help you better understand pneumatic products.

（FK9009）