Firstgas is committed to ensuring the safety, reliability, and longevity of our gas distribution pipeline network. Research shows that many polyethylene (PE) pipes installed between the 1960s and early 1980s are prone to weaknesses under certain conditions. To ensure ongoing safety and reliability, it’s important we address the key factors that contribute to these possible weak points on our network, such as:
- Squeeze-offs on pipelines which is a method used to temporarily stop the flow of gas in a pipe by compressing it with specialised tools.
- Particles, such as rock particles contacting or damaging the pipe surface.
- Excessive pipe bending can also lead to cracks.
Our approach to pre-85 pipelines
Firstgas has developed a comprehensive strategy to help prioritise which segments of pipeline should be replaced first, focusing on those with the highest risk.
A key innovation of this program is the use of an in-line camera to assess pipeline conditions while they remain in service. This cutting-edge technology brings several advantages:
- Understand the "as-is" state of the pipeline without disruption.
- Pinpoint exact locations that need replacement, avoiding unnecessary work.
- Minimise costs and reduce inconvenience for customers during maintenance.
What’s Next?
The current plan is to inspect our pre-85 pipelines using the in-line camera, starting with areas that have the highest need according to our assessment, while keeping the impact to customers to a minimum.
The bigger picture
At Firstgas, it’s our job to operate nearly 5,000km of gas distribution pipelines. Together, they provide gas to over 67,000 commercial and residential customers throughout the North Island.
Keeping our network well maintained, as well as regularly upgrading and improving it, is a big task, which the Pre-85 upgrade programme is a part of. To help us manage this and many other projects and initiatives, we have an Asset Management Plan, which you can find here.