PG&E Enhances Safety Measures for New Polyethylene Gas Pipe Installations with Advanced Detection and Fusion Techniques

PG&E is currently implementing new underground natural gas piping using single-wall, bright polyethylene pipes, incorporating specific safety measures for detection and joining. This initiative aims to leverage the non-corrosive properties of polyethylene while addressing critical safety considerations inherent in buried infrastructure. The utility's ongoing work is observed amidst a broader industry focus on pipeline integrity and public safety.

A key concern for underground pipes is their detectability to prevent accidental rupture during other utility work or construction. According to Robert O'Reilly, who observed the installations, PG&E is addressing this by laying "> some kind of tracer tapes above the pipes that CAN be detected by standard metal detectors." Additionally, the "> bright pipe color also provides a better visual clue than galvanized pipe," enhancing visibility during excavation.

Ensuring leak-proof connections is paramount for gas pipelines. O'Reilly noted that PG&E is employing "> saddle fusion" for durable, leak-proof joints. This method involves clamping a coupling over each pipe-end and using "> a special heating tool to heat the outside of the pipe and the inside of the coupling, fuse it all together, all around" to create a secure connection. This technique is recognized in industry practices for polyethylene pipe installation.

Polyethylene pipes are widely adopted in urban gas transmission systems due to their corrosion resistance, flexibility, and ease of construction. However, the use of plastic piping has faced scrutiny, particularly older vintages like DuPont's Aldyl-A, which federal regulators singled out as being at risk of premature cracking. Past incidents, such as a 2017 explosion in Yuba City attributed to a fabrication error in a butt fusion joint of an Aldyl-A plastic main installed in the 1970s, underscore the importance of robust installation and integrity management.

In response to historical challenges and regulatory mandates, PG&E has implemented comprehensive safety plans, including a program to replace approximately 1,500 miles of Aldyl-A pipe over 15 to 20 years. The utility emphasizes its commitment to pipeline safety through continuous monitoring, advanced inspection technologies, and adherence to federal and state regulations, aiming to ensure the long-term reliability and safety of its extensive gas distribution network.