Compressed air leaks: Common causes and how to prevent them

Compressed air systems are essential to numerous industrial facilities across various industries. And for decades, they were also among the most inefficient components. But that’s changing fast due to rising energy prices, increasing consumer demand, and stricter environmental standards. Today, preventing compressed air leaks is crucial to a company’s bottom line. 

One primary source of inefficiency and energy waste is air leaks. These leaks not only increase costs. They also compromise the stability and performance of the entire system.

In many plants, air leaks can waste as much as 20%-30% of the compressor’s output. However, proactively addressing air leaks can help you reduce that figure to 10 percent or less.

In this article, we’ll explore the primary causes of compressed air leaks. You’ll also learn how to prevent them from forming in the first place and how to detect and repair them. 

Primary causes of compressed air leaks

Several factors can lead to air leaks, from poor installation practices to operational wear and tear. Highlighted below are the most common causes:

• Loose fittings or connections: Whether it’s due to aging infrastructure, substandard materials, or external pressure, connections can become loose. Air escapes from the system when these unions are no longer airtight.  Those connection include:
  • Couplings
  • Hoses
  • Seals
  • Push-to-lock fittings
• Improper installation: Issues often arise from using low-quality filters, regulators, and lubricators (FRLs). Additionally, double-ferrule compression fittings, an industry standard, are prone to leaks when installed incorrectly.
• Damaged or worn components: Essential components can wear down or get damaged over time. These include pipe joints, flanges, and the previously mentioned FRLs. Doing so usually exacerbates the leakage problem by forcing more air out of the leaks.
• Vibration: Vibrations can loosen fittings and connections, especially in systems with reciprocating compressors. 
• Threaded pipe issues: Threaded pipes are more susceptible to leaks than welded pipes, especially if they are not sealed properly. 
• Open drain traps: Accumulated debris like rust and dirt can cause drain traps to remain open, allowing air to escape.

Preventing compressed air leaks

Establishing regular maintenance checks, investing in modern fittings, and training employees are all crucial steps toward a leak-free operation. 

• Tightening joint and connection leaks: Most leaks occur at joints and connections. Simple solutions like tightening a loose connection can sometimes resolve these issues. However, more complex repairs may involve replacing faulty components such as couplings, fittings, or hoses.
• Quality materials and proper installation: Using high-quality fittings, disconnects, hoses, and tubing can prevent many leaks from occurring in the first place. When installing these components, it’s crucial to use appropriate thread sealant, ensuring airtight connections.
• Isolating non-operating equipment: Equipment no longer in use can be a leak source. It’s best to isolate such equipment with a distribution system valve to prevent unnecessary leaks.
• Reducing system pressure: Minimizing system header pressure is an effective method to reduce leak rates. As pressure across an orifice or leak decreases, so does the flow rate, thus reducing leakage rates.
• Single-ferrule compression fittings: These fittings are simpler and eliminate specific potential leak points present in the double-ferrule designs. By reducing the number of interior parts, they offer more straightforward installations, minimizing issues like lost parts or damaged ferrules.

The importance of a leak prevention program

Every facility that employs a compressed air system should prioritize establishing a comprehensive leak prevention program. Central elements of an effective program include:

• Identification and tagging: Detecting and marking the leak sources.
• Tracking: Monitoring leak history and patterns.
• Repair: Addressing and fixing the leaks.
• Verification: Confirming that the repairs are effective and durable.
• Employee involvement: Engaging staff across all aspects of production ensures consistent monitoring and immediate addressing of leaks.
• Reassessment: Reassess and fine-tune the system after repairs. If necessary, work with a specialist to optimize compressor controls to prevent new leaks from forming. 

This program should be a foundational pillar of your overall strategy to enhance the system’s performance, reliability, and cost-effectiveness. 

Detecting leaks

Detecting compressed air leaks can be challenging due to their invisible nature. However, with a combination of technology and tried-and-true methods, they can be identified and rectified:

• Acoustic detectors: These devices utilize directional microphones, amplifiers, and audio filters to recognize the characteristic hissing sounds of air leaks. You can use visual indicators or earphones to pinpoint leak sources.
• Soapy water application: While time-consuming, applying soapy water with a paintbrush to suspected leak areas is a reliable detection method. If a leak exists, bubbles will form, indicating the leak’s location.
• Air flow meters: In-line air flow meters continually monitor a compressed air system for pressure drops and other signs of airflow leaks. Digital, rather than analog, models can provide precise data in real-time to you or your maintenance team. This enables you to identify leaks and repair them right away. 

Effective leak repairs

Upon detecting a leak, the next step is repair. Solutions range from simply tightening a connection to replacing faulty equipment. Ensuring high-quality fittings and proper thread sealants can significantly reduce leak incidences. Lowering the demand air pressure also reduces the leakage rate.

Leaks in compressed air systems represent a significant source of wasted energy and operational inefficiency. By understanding their common causes and adopting a robust leak prevention program, you can significantly improve your system’s performance, save on energy costs, and extend the life of your facility’s equipment.