Are you tired of dealing with air leaks, pressure drops, and other pneumatic system issues? If you're using a pneumatic system, it's crucial to choose an air treatment unit that can filter out impurities, regulate pressure, and lubricate the components. However, with so many options available on the market, it can be overwhelming to select the right FRL (filter-regulator-lubricator) combination unit for your application.

A crucial step in ensuring the optimal performance of your system is selecting the right air treatment unit. This guide will walk you through choosing FRL combination units for your specific needs.

What is an FRL Unit in Pneumatic Systems?

Before speaking about how to choose an air treatment unit, let’s understand some basics. 

An FRL unit is a critical component of a pneumatic system that filters, regulates, and lubricates compressed air. By removing impurities and regulating pressure, the FRL unit ensures the proper functioning of pneumatic tools and equipment. 

Why Do You Need an Air Treatment Unit?

Air treatment units are essential for maintaining the performance and longevity of your pneumatic components.

The air that enters the system can contain dust, oil, water, and other contaminants that can damage the valves, cylinders, and other parts. Moreover, the air pressure and flow rate need to be regulated to ensure consistent and accurate operation. Finally, lubrication is necessary to reduce friction and wear, especially in high-speed and high-cycle applications.

Choosing the Correct Air Treatment Unit

When choosing a pneumatic FRL unit, there are several factors to consider. Here are some of the essential things to keep in mind:

 1. Application Requirements

Consider the application requirements for your pneumatic system. What is the required pressure range? What is the flow rate of compressed air? Are there any specific environmental considerations, such as temperature or humidity?

 2. FRL Combination or Separate Units

You can purchase separate filter, regulator, and lubricator units, but it is often more cost-effective to buy an FRL combination unit that includes all three components. The combination unit ensures a compact and easy-to-install solution.

Let’s check what each unit does:

  • Filter

The filter is the first unit in the FRL system and is responsible for removing contaminants such as dirt, dust, water, and oil from the compressed air. The filter typically consists of a filter element that traps the contaminants and a drain mechanism that allows the collected contaminants to be removed from the system. There are different types of drain mechanisms, including manual, automatic, or semi-automatic, which can be chosen based on the specific application and requirements.

  • Regulator

The regulator is the unit in the FRL system that regulates the pressure of the compressed air flowing through it. It maintains a constant downstream pressure, preventing the pressure from dropping below a certain level or exceeding the maximum pressure limits. 

You can use an air pressure gauge to measure the pressure of compressed air in various industrial and automotive applications.

  • Lubricator 

The lubricator is responsible for introducing a controlled amount of oil into the compressed air system to lubricate the downstream components. Lubrication reduces friction and wear, which can improve the performance and lifespan of pneumatic tools and other downstream equipment. 

You can either buy a complete air treatment unit or buy separate units. If you need only two functions, such as filtering and regulating, then a pneumatic filter regulator unit will be a better choice. 3-stage units offer filtration, regulation, and lubrication in a single unit, making them ideal for applications where all three functions are required.

 3. Flow Rate 

You need to determine the required airflow rate for your application. This will help you select the correct size of the FRL unit. You can find the required flow rate by calculating the total air consumption of your pneumatic system. Calculate the maximum air consumption of your system in cubic feet per minute (CFM) or liters per minute (LPM) and choose an FRL unit that can handle that flow rate.

 4. Filtration Level

The filtration level of the FRL unit should be chosen based on the level of cleanliness required for your application. If your application requires a higher level of filtration, then you should choose a unit with a higher filtration rating.

 5. Thread Size

The thread size (NPT ¼”, ⅜”, ½”, ¾, 1”) of the FRL unit should match the size of the airline to which it will be connected. You will need to determine the appropriate thread size for your application before selecting a unit.

 6. Environment 

The environment in which the FRL unit will be used is an important factor to consider. If the unit will be exposed to harsh conditions, such as extreme temperatures or corrosive substances, you may need to select a unit with a higher level of durability and resistance.

 7. Drain Type

You'll find manual or semi-automatic drains at the bottom of the filter bowl while browsing for air filter units. With this feature, you can empty liquids and collected particles from the filter. Manual filters require you to do this manually, while semi-automatic filters drain automatically when the system is depressurized, though they can also be operated manually. For frequent use of your compressed air system throughout the day, it's advisable to choose a filter with a semi-automatic drain.

Two Valves You Need for Air Compressors

Shut-Off Pressure Relief Valve

One important component to consider buying is the shut-off pressure relief valve. This valve is designed to protect your system from over-pressurization by shutting off the air supply if the pressure exceeds a predetermined limit. In addition to protecting your equipment from damage, a shut-off pressure relief valve can also prevent safety hazards and downtime caused by pressure-related malfunctions.

Soft Start/Pressure Relief Valve (Dump Valve)

Another important component to consider is the soft start/pressure relief valve, also known as a dump valve. This valve is designed to prevent sudden pressure spikes during start-up. It allows for a gradual increase of downstream pressure during initial startup and ensures quick system pressure exhaustion when needed. It can help to prevent damage to your equipment, which can further protect your equipment and reduce wear and tear.

Double-check the blog once you want to buy an air treatment unit.