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Water in Compressed Air Lines: A Complete Troubleshooting Guide

Michael Schapoehler
Posted by Michael Schapoehler on May 4, 2023 3:09:37 PM

Compressed air systems are the standard in various industries for their efficiency and reliability. However, one common issue pneumatic engineers may face is water in compressed air lines, causing many problems, including reduced system efficiency, corrosion, and equipment failure. If you've found yourself in this unfortunate circumstance, keep reading: This blog post will provide a step-by-step guide on troubleshooting water in pneumatic air lines so you can identify the source of the problem and take corrective action.


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Causes for Water in Pneumatic Air Lines | Troubleshooting Guide | Prevention Tips | Pneumatic Resources 


Causes for Water in Compressed Air Lines 

First and foremost, it is essential to understand the causes of water in pneumatic air lines. Several factors can contribute to this issue, including inadequate filtration, incorrect or poorly sized piping, and a fast change in external temperature and humidity levels. When troubleshooting these issues, it is vital to start by identifying the water source, which may require some basic diagnostic tests, such as checking the moisture level in the compressed air using a moisture meter. 


Learn more about the causes, dangers & solutions

 The cause of moisture in air lines

 Why moisture must be removed from air lines

 Best practices to prevent moisture buildup

 Cost-effective products to remove moisture from air lines

Read blog post


  Water in Compressed Air Lines:
Troubleshooting Guide 


Step 1: Identify the Sources of the Water

Check the following to locate the source of the water:

1. Drain your air compressor using the drain at the unit's bottom. In many cases, this could be a manual valve. Adding a valve that is either float-driven or electric-driven on a timer eliminates a person to remember to drain it and be the first line of defense. This is particularly crucial during warm months when moisture accumulates more rapidly. Additionally, remember that high demand means more frequent draining is necessary.

2. Compressor location can often be the biggest problem with water generation. For example, suppose the compressor is located in an outside building or a small non-humidity-controlled room. In that case, the compressor will not be able to breathe, and the room will starve the compressor of good air. Thus the space will become hot as the compressor runs, exasperating the problem and causing water condensation, a natural byproduct of this process.

3. Monitor your plants' ambient air temperature and humidity levels. Sudden changes in temperature and humidity can lead to moisture-related issues. If you notice such changes in your plant, it is recommended to investigate other potential sources of moisture to determine the best course of action.

4. Check your filtration devices are working properly. Properly functioning filters remove moisture from the compressed air, ensuring that the air is dry and free of contaminants that could damage the system. If the filter is clogged or damaged, it may be necessary to replace it. (Additionally, If these devices do not exist in your pneumatic system, that may be the source of your problem).

5. Inspect your air pipes for the following:

Check the temperature of your pipes. Sometimes, the source of moisture occurs when hot air is suddenly forced through cool air pipes, causing condensation.

• Check the pipe sizing is appropriate for the air flow. If the pipes are too small, compressed air will move more slowly through them, increasing the chances of moisture condensation.

• Check how the pipes are structured and installed. Improperly installed piping can create low points or pockets where water can collect and remain stagnant. Over time, this stagnant water can lead to corrosion and damage to the pneumatic system.

• Check for obstructions or damage. If any issues are identified, repairing or modifying the piping system may be necessary.


Need a hand with any of these steps? We've got your back.

Identifying the water source may involve performing basic diagnostic tests, such as checking the moisture level in the compressed air using a moisture meter.

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Step 2: Check Your Filtration Setup

Once the water source is identified, the next step is to check your filtration system is efficient enough to handle your system's moisture removal needs. Inadequate filtration can cause moisture to accumulate in the compressed air, leading to water in the pneumatic air lines. Your system may already have a filtration device installed, but sometimes, one may not be enough.

See the example below of a production facility application with an after-cooler (#2, cooling and removing water roughly), refrigerated air dryer (#4, large-scale dehumidifying), multiple water & mist separators (#3, #6, #7, for main-line & point-of-use water/mist removal), and odor-removing filters (#8, #9) installed. 

water separation smc

Not all systems require this amount of filtration, but the point is it's possible you need multiple water-removing technologies installed in your system at different points of your air line. Contact us if you need help identifying, sizing, and selecting filtration devices for your system. (It's possible we can visit your plant and troubleshoot in person).

> More information about water-removing technologies


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AMG Water Separator by SMC

Effectively removes 99% of the water from pneumatic lines.

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Step 3: Address Humidity Issues

If high humidity levels contribute to water in the pneumatic air lines, it may be necessary to address humidity issues in the facility. Addressing this may involve installing a dehumidification system or improving ventilation and airflow in the facility. Additionally, a desiccant dryer can remove moisture from the compressed air before it enters the pneumatic system.

Step 4: Monitor and Maintain

Once corrective action has been taken to address the water in the pneumatic air lines, it is vital to monitor and maintain the system. Regularly monitoring the compressed air quality can help identify any issues before they become significant problems. Additionally, regular maintenance of the filtration and piping systems can help prevent water from accumulating in the pneumatic air lines.


Prevention Tips

Preventing water in pneumatic air lines is often easier than troubleshooting this issue once it has already occurred. You can take several steps to prevent water from entering your system in the first place. 

> Read our prevention tips


In summary,  It is safe to say that most plant equipment is not designed to have water going through it.  Valves, Cylinders, and the process they support are designed to have clean, dry air.  The cost of maintenance and downtime of a poorly maintained system can add up to billions of dollars a year. Troubleshooting water in compressed air lines can be a complex and challenging task, so remember to reach out for help if you can't find the source or solution to your problem. With the right tools and techniques, it is possible to identify the source of the problem and take steps to resolve it. 

Additional Resources 

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Topics: Pneumatics, Explainers, Maintenance, SMC

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