Understanding Air Channel Testing and Burst Testing for PVC Liners

PVC liners are critical in environmental containment projects, including landfills, wastewater lagoons, mining, and agricultural applications. Their performance is directly tied to their ability to remain leak-free and structurally sound over time. Two of the most reliable quality assurance methods for ensuring this are air channel testing and burst testing. Both techniques are essential tools for verifying seam integrity in PVC liner installations, helping prevent costly failures and environmental hazards.

The Importance of Seam Integrity

Seams are often the most vulnerable points in a PVC liner. Even if the liner material itself is flawless, poorly sealed seams can allow liquids or gases to escape, compromising containment. Seam testing not only confirms that the installation meets required specifications. It also builds confidence that the liner will perform as designed under operational conditions.

Air Channel Testing

Air channel testing is a non-destructive method used to evaluate the quality of thermal or hot wedge welded seams in PVC liners. During the welding process, an overlapping dual-track weld is created with a small air channel between the tracks.

How it Works:

1. After the seam is welded, technicians insert a needle or valve into the air channel.

2. Air is pumped into the channel to a specified pressure.

3. The seam is monitored for a set period of time to ensure there’s no loss of pressure.

If the pressure holds steady, it’s a strong indication that both weld tracks are continuous and secure. If the pressure drops, there may be a flaw in the weld that requires repair.

Advantages of Air Channel Testing:

Air channel testing is fast, efficient, and easy to perform on-site, making it an ideal method for inspecting large areas of liner seams. Because it is non-destructive, the liner remains intact and ready for use after testing. Additionally, this method is highly effective at detecting pinholes, missed welds, or other seam defects before the liner is put into service, providing an early warning that can prevent costly failures.

Burst Testing

Burst testing is a destructive test method used to verify seam strength and quality. Rather than leaving the liner intact, a sample of the welded seam is cut from the installation for testing.

How it Works:

1. A seam sample is placed into a burst testing apparatus.

2. The sample is pressurized—often with air or water—until the seam fails.

3. The failure point and pressure reading are recorded.

This method confirms the seam’s actual strength against internal pressure and ensures it meets or exceeds project specifications. While the tested section cannot be reused, burst testing provides direct, quantifiable data about the weld’s performance.

Advantages of Burst Testing:

Burst testing provides an exact, quantifiable measure of seam strength, confirming that the weld meets or exceeds project specifications. By testing to the point of failure, it identifies whether the weld is stronger than the liner material itself, which is a key indicator of a high-quality seam. While the tested section cannot be reused, this method ensures confidence in the liner’s long-term performance and compliance with industry standards.

Using Both Methods for Reliable Results

Air channel testing and burst testing serve different purposes, and many projects use them in combination. Air channel testing quickly checks 100% of accessible seams without damage, while burst testing offers concrete proof of seam strength. Together, they create a thorough quality control program that safeguards against leaks and ensures long-term containment.

Ensuring Long-Term Performance and Reliability

When it comes to PVC liner installations, seam testing is an essential part of protecting the environment and ensuring project success. By incorporating both air channel testing and burst testing into a quality assurance plan, environmental containment systems can achieve maximum performance and reliability.