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5 Best Air Compressor Water Separators & How They Work

Best Air Compressor Water SeparatorsWater Separators are designed to remove contaminants from the compressed as it leaves the air compressor and before it gets to your tools. in this detailed buyer’s guide, we will look into the best water separators based on application. In addition, to how they work and how to choose the best one for your air compressor. 

Your new air compressor is sitting in your shop, gleaming and in the light.  Over on the workbench are all your well cared for air tools. They may be woodworking tools like nailers or automotive tools.  The next thing to think about is protecting those tools from that air compressor.

It may seem strange to think about protecting those tools from the very thing that can bring them to life, but the nature of air compressors can make them the biggest threat to the tool’s wellbeing and longevity.

Compressing air creates a water problem.  All air contains water vapor. Compressing that air forces that water vapor out and the water must collect somewhere in your compressor.  The logical point for the water to collect is the air tank.

Air compressor manufacturers put a drain valve on the bottom of the air tank for a reason.  Your regular shop maintenance routine should include draining that air tank on a regular basis. Even if you are diligent, there is still a problem.

The Other Problem

Best Air Compressor Water SeparatorsAs you are working, the pressure in your air tank varies up and down, and it streams air down the connection hose to your tools.  As the pressure varies in the tank, the air picks up water vapor that ends up in your valuable tools. Water in the cylinders of air tools makes for bad results over time, even if you are careful to oil those tools with each use.

You need to think about protecting those tools by removing that water from the compressed air before it can reach your tools and do more harm.  The answer is to install a water separator on your compressed air system. This will ensure that you are delivering clean, dry air to your tools.

What is an Air Compressor Water Separator?

Water Separators are designed to remove contaminants from the compressed as it leaves the air compressor and before it gets to your tools.  These contaminants can include:

  • Liquid water
  • Water vapor
  • Solid particles
  • Oil
  • Oil vapor

How do Water Separators Work?

There are two different methods by which compressed water separators remove contaminants from the compressed air in your system.  Both are effective at removing the contaminants from your compressed air supply.  

Centrifugal Separators

Centrifugal separators are designed to induce a rotary or spinning motion to the compressed air as it passes through the separator.  This action causes the contaminants to speed up. As the particles, oil, and water speed up, they more to the outer edge and collect on the inside of the separator housing where they drain to the bottom and can be drained.

Draining the centrifugal air separator can be done either manually of with the installation of an automatic drain system.  

Coalescing Separators

Coalescing separators utilize a filter element to trap contaminants in your compressed air supply as it moves through the filter.   The compressed air is forced through a filter medium from the inside of the filter to the outside, where the compressed air exits the separator. You must replace these filter elements on a regular basis.

Keeping Your Air Dry and Clean – Our Picks for the Best Compressed Air Water Separators

Different situations and installations call for different types and sizes of water separators.  We have searched and considered many different makes, models, and types of water separators for each use, and these are our picks as the best for each application.

Best Overall Compressed Air Water Separator

1.PneumaticPlus SAD4002 Water SeparatorPneumaticPlus SAD4002 Water Separator

Our pick for the best overall water separator is the PneumaticPlus SAD4002.  For general compressed air use on a job site or in a shop, you can count on this piece of equipment to keep the rest of your air tools clean and dry.

With the PneumaticPlus water separator, you get the full package of features at a nice price.  This water separator for your compressed air system has all the features that you want for the protection of your tools without busting your budget.

  • Automatic drain
  • Float drain includes a ¼” tube connection
  • Metal bowl and housing
  • Sight glass
  • ½” NPT Female Thread ports
  • 10-micron filter element
  • No electricity required to operate the automatic drain.

Pros & Cons

Pros

  • High-quality construction with an eye to details
  • A convenient sight glass for quickly checking the separator
  • It empties when the air pressure is removed which is a great feature

Cons

To be honest, we couldn’t find any negative comments about the compressed air water separator.  For the price, this is a great way to protect your air tools from contaminants in your compressed air supply.

Best Compressed Air Water Separator for Painting

2. PneumaticPlus SAU3030M-N03G-MEP Three Stage Air Drying SystemPneumaticPlus SAU3030M-N03G-MEP

If you intend to spray any kind of finish, whether it is automotive paint or wood lacquer, you need to make sure that you are delivering the highest quality air to your paint gun possible.  Contaminants in your air supply can cause issues such as fisheye, finish pop, and others.  

To get this higher quality of air with the required airflow and pressure stability, you should consider the PneumaticPlus SAW3030< Three Stage Air Drying System.   The quality of air that the PneumaticPlus SAW3030 delivers to you spray booth will ensure that your finishes are as near perfect as can be accomplished. This three-stage unit includes:

  • Maximum pressures up to 250psi with a maximum operating pressure of 150psi
  • 16scfm flow rate at 100psi
  • Includes a 10-micron filter element and a .3-micron coalescing filter element for the driest and cleanest possible compressed air.
  • Manual drains and metal bowls 
  • The regulator keeps pressures stable and has an easy to read gauge
  • No moving parts and no electricity required

Pros & Cons

Pros

  • Accurate regulator with automatic blow off so the gauge always reads accurately
  • Well-constructed and tough.  Easy to mount and install.
  • Can easily be reconfigured for custom installations.

Cons

  • Manual drain
  • In high humidity areas, it fills up quickly

Best Value Compressed Air Water Separator

3.LE LEMATEC Air Compressor Filter and Water Separator

For those compressed air systems that get only occasional use, a more economical solution to trapping and removing contaminants from LE LEMATEC Air Compressor Filter and Water Separatoryour compressed air supply may be the best choice.  If you only use one pneumatic tool or you are interested in putting dry air into your car tires, an inline water separator may be your best choice.

The Le Leatec Inline compresses are water and oil separator is convenient to use and provides a budget-conscious means of providing clean air at the end of your air hose or at the inlet of your air tools.  This small separator can be mounted to your tool or the end of your air hose.  

  • Traps water, oil, and dirt
  • Shock-proof and durable
  • Convenient push-button drain
  • All brass fittings and metal housing
  • Comes with a money-back guarantee
  • Replaceable filter element 

Pros & Cons

Pros

  • Simple, easy to use, and install.
  • The push-button drain system is ingenious
  • Small size is handy in a shop with limited space
  • Cheap enough to mount one on each of my air tools

Cons

  • It’s small and fills with water very quickly
  • Airflow may be restricted

Best Auto Drain Water Separator

4.THB ½” Heavy Duty Particulate Filter and Moisture Trap

Getting an automatic drain on a reasonably priced water separator can be a challenge.  Most of the low and mid-range compressed air Heavy Duty Particulate Filter Moisture trap water seperatorwater separators suitable for home or hobby shops are just too expensive to easily justify.  However, THB has an offering that might just suit your needs.

The THB 1.2” heavy-duty particulate filter and moisture trap is a well built and durable water separator that comes standard with an automatic drain system at a price that won’t make you flinch.  It isn’t short on features either.

  • Heavy-duty construction for long life and durability
  • ½” female NPT fittings
  • Internal float drain
  • 140cfm flow rate
  • 215psi maximum out pressure
  • 250psi maximum input pressure
  • Sight glass on the bowl

Pros & Cons

Pros

  • Easy installation 
  • Well-constructed
  • Works well 
  • The auto drain is fantastic

Cons

  • The float value sometimes sticks and doesn’t drain

 

Best High-Volume Compressed Air Water Separator

5.PneumaticPlus SAF600 

If you run a shop where large flows of clean and dry compressed air required to keep machinery or larger tools operating, you need a PneumaticPlus SAF600-N10BD-MEPhigh flow compressed air water separator in your system.  High flow rates can generate more water that lower airflow rates. A well-designed water separator can save you hundreds or thousands of dollars in downtime and maintenance costs.

The PneumaticPlus SAF600 High Flow water separator installed in your air system can be what saves you from those additional costs.  These water separators are designed for the task of dealing with water, oil and particulates in high airflow situations. The features included reflect that design.

  • Automatic drain
  • Metal bowl and housings
  • Sight Glass
  • 10-micron filter element
  • Includes mounting bracket
  • Large airflow rate up to 460cfm at 90psi
  • Maximum supply pressure 250psi
  • Operating pressures 0 to 150 psi
  • 1” inlets and outlets

Pros & Cons

Pros

  • Easy to mount and install
  • All-metal housing and bowl are resistant to solvents
  • Easy to change filter
  • Automatic drain means less maintenance

Cons

  • If you don’t change the filter regularly, it restricts the flow rate

 

FAQ’s

Do I need a water separator?

If you use compressed air, even if only to inflate your tires, you should have a water separator installed on your compressed air system.  Most people don’t realize how destructive water can be to tools and even to tires. Water can rust or deteriorate tools and tires, shortening their life.

Where does the water in my compressor tank come from?

As the air pump compresses the air, it heats up.  In the air tank, as you use the compressed air, it cools and any water vapor that was in the compressed, heated air condenses on the inside of your air tank and collects at the bottom.   The water will eventually corrode the tank and can potentially be carried down the air hose to your tools.  

Keeping Things Dry

In the end, it is all about protecting your investment in the tools and other uses of your compressed air.  Keeping water, oil, and other contaminants from migrating down the system and into your tools are the goal. No matter whether you are a casual hobby compressed air user, or you run a shop that uses high volumes of compressed air, it is in your best interest to install a water separator on your compressed air system.

We hope that this article has answered some questions and given you the information that you need to decide on whether to install a compressed air water separator.   If you do decide that your system needs to have a water separator installed, the information here can help you find the best water separator for your needs.

AircompressorsUSA Team

AircompressorUSA Team is full of diverse writers from different industries. Our team includes small business contractors, assembly line managers, scuba shop owners, garage owners & More. Our Team makes every effort to provide the most accurate information to our readers and buyers.

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