By: Mario Carbone, Progressive Pipeline Management
NASTT Fall 2020
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Since 2002, Progressive Pipeline Management has been renewing natural gas pipelines in challenging situations including highways, bridges, railroad lines and environmentally sensitive areas. Starline® Cured-in-place-lining is a proven, cost effective trenchless technology that extends the life of a pipeline by 100 years.
Pipelines on bridges cannot be repaired using conventional methods of replacing the pipe.
In 30 years, I haven’t met a utility that didn’t have pipelines along bridges in their inventory. As bridges age, so do the pipelines. Like us, they are getting older. Over forty percent of the bridges in the US are over fifty years old. In the Northeast, gas pipelines and bridges are typically 75 - 100 years old.
As they age, pipelines are vulnerable to corrosion. Leaks come from corrosion, which is accelerated in pipelines along bridges. Repair of a gas pipeline alongside a bridge or overpass is nothing like a repair in a typical roadway where a pipeline is buried. Let’s say a leak is identified in the abutment wall. Go-to methods are to put a sleeve on or to remove the pipe from the abutment wall and replace the piece of pipe. Here’s the dilemma. The owner of the bridge will never allow that. If you can’t disturb the pipe on the bridge, or cut and cap the main, there are no viable alternatives.
Leaking pipelines on bridges cannot be repaired using conventional methods of replacing the pipe. There is another way that has been around for 30 years. The Starline (R) Cured-in-place-lining is a proven and cost effective way to repair pipelines without disturbing the bridge.
WHY ARE PIPELINES ON BRIDGE CROSSINGS SO DIFFICULT TO REPAIR?
Pipelines run under or alongside and traverse the bridge’s abutment walls. The position of some of these gas pipelines places them in a problematic location as they are mostly hung under or alongside the bridge structure, limiting access to the pipeline. In some cases, and the most convenient, the pipeline is resting on top of the structure completely exposed except for where it re‐enters the road or offsets into the abutment walls. Most of these bridge or overpass crossings place the pipeline through the concrete abutment wall of the structure, either with a protective sleeve and in some cases without a sleeve.
Natural Gas Pipeline in Abutment of a Bridge
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Bridges are highly susceptible to the elements. Wind, salt and extreme temperatures accelerate corrosion, which is the reoccurring issue, especially where the hangers supporting the pipeline makes contact with the gas carrying pipe. The greatest corrosion concerns are within the abutment wall itself, where the concrete accelerates the localized corrosion. The pipeline is weakened at that juncture and in most cases a gas leak is present. Excessive corrosion of the pipeline where the pipe enters the abutment wall of the bridge cannot be repaired without removing the pipe.
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