T.D. Williamson conducted a series of tests to evaluate the effects of squeezing on polyethylene pipes. The results have highlighted the significant difference between compliant and non-compliant procedures.
In a series of tests on polyethylene (PE) pipes, T.D. Williamson (TDW) has assessed the impact of squeezing, uncovering notable differences between compliant and non-compliant procedures.
In one test, a 4-inch medium-density polyethylene (MDPE) pipe was subjected to a compliant squeeze-off following ASTM F1041 standards, which specify the rate of compression and release.
After the squeeze, the pipe’s wall showed only a slight deformation, with a decrease in wall thickness of about 3.7 per cent.
This minimal deformation indicated that the pipe remained in good condition and suitable for continued use.
However, a second test, where the squeeze-off was performed at twice the recommended speed, led to dramatic results.
The pipe experienced significant plastic deformation, with an 11 per cent reduction in wall thickness. More concerning was the appearance of a crack on the outer wall, measuring 3.8cm in length and penetrating about 8.5 per cent of the total wall thickness.
As the case study confirms, the importance of following strict procedures cannot be overstated.
However, despite training and the best intentions, human error is inevitable. To counteract this risk, the introduction of engineered solutions has become a critical part of the industry’s safety strategy.
TDW’s development of engineered safety systems, such as the POLYSTOPP® Quick Connect system, marks a significant advancement in reducing the risks associated with PE isolation.
This system, specifically designed for low-pressure hydrogen networks, eliminates the need for squeezing and instead uses an advanced fitting system that provides a leak-proof and permanent solution.
The POLYSTOPP Quick Connect system’s unique fusion process integrates the fitting with the pipe, making the joint as strong as, or even stronger than, the pipe itself. This fusion ensures that no gas can escape, significantly enhancing the safety of the pipeline.
Further, the fusion process is monitored and verified using barcodes and digital scanning, providing full traceability and ensuring the success of the fusion, eliminating human error during the critical isolation process.
Pipeline operations, particularly those involving the isolation of PE pipes, require the highest levels of care, precision, and awareness.
Risk mitigation is fundamental to every aspect of pipeline operations and requires the right equipment, expert handling, and rigorous procedures.
However, despite strict protocols and advanced technology, it is often the person behind the controls who remains the final safeguard against potential failure.
Historically, one common method for isolating PE pipes has been the squeeze-off process, which involves compressing the pipe between two parallel, rounded bars using hydraulic or mechanical tools.
This technique has been widely used in gas distribution networks for decades, primarily due to its efficiency and cost-effectiveness. However, as simple as it may appear, the process comes with numerous potential risks. A single lapse in attention can lead to irreversible damage to the pipe and even pose safety threats to both personnel and the environment.
TDW’s commitment to innovation extends beyond just PE pipe isolation for gas networks.
In a recent breakthrough, the company successfully completed a zero-leak isolation test on a 100 per cent hydrogen pipeline operating at six bars pressure for R-GDS in France.
This successful test demonstrated how the POLYSTOPP Quick Connect technology ensures leak-free isolation, even in emerging hydrogen networks, while also eliminating fugitive emissions – a crucial step in reducing the environmental impact of energy systems.
The importance of this development cannot be understated.
As the energy industry moves towards cleaner fuels, such as hydrogen, the risks associated with pipeline isolation and integrity will evolve.
Using engineered solutions like POLYSTOPP not only ensures safety during these operations but also contributes to a more sustainable future by eliminating emissions during critical isolation processes.
The squeeze-off procedure for PE pipes, while effective when performed correctly, highlights the inherent risks in relying on human judgement to ensure pipeline integrity. The introduction of engineered solutions like the POLYSTOPP Quick Connect system provides a safer, more reliable alternative, offering greater assurance of pipeline safety while reducing the potential for human error.
As the industry embraces emerging energy technologies such as hydrogen, the need for safer and more efficient isolation techniques will continue to grow.
By shifting towards engineered solutions, operators can not only safeguard their pipelines but also contribute to the transition towards more sustainable and environmentally responsible energy systems.
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This feature also appears in the May edition of The Australian Pipeliner.