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Nick Lehnhoff of A&W Coatings: Rehabilitating Service Water Pipes at Mansfield Mill
The existing 54-inch steel raw water suction pipeline was heavily deteriorated by abrasion and corrosion. Here, it can be seen before and after being rehabilitated using Warren Environmental’s 301-14 high-performance epoxy.
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hen International Paper needed to rehabilitate corroding steel pipes that carry water to cool operations at its Mansfield Mill, it called in A&W Coatings. Project Engineer Nicholas Lehnhoff spoke with Municipal Water Leader about the project’s unique challenges and the benefits that the Warren Environmental epoxy that A&W uses could bring to the facility. Municipal Water Leader: Please tell us about your background and how you came to be in your current position.
26 | MUNICIPAL WATER LEADER | June 2022
Nick Lehnhoff: We’ve actually worked at that mill twice, in 2019 and in 2021. Last year, we were hired to rehabilitate the pipe that carries water from a pond to cool the mill’s various operations. The pipes are 100–125 feet long, and 24‑inch risers come out of the pipe and go to different parts of the mill. Suction lines draw water in from a pond, and grit can enter those lines. As the grit is sucked up out of the riser, it creates a sort of vortex. The grit acts as an abrasive, and rust forms and builds up in the pipe, which also causes corrosion. We found that the steel pipes were heavily deteriorated in spots. The first time we worked there, we actually had to patch a few spots with plates. First, we removed the buildup in the pipe with high-pressure washers. Once we got most of it off, we blasted the pipe with abrasive municipalwaterleader.com
PHOTOS COURTESY OF A&W COATINGS.
Nick Lehnhoff: I have been with A&W for a little over 2 years. I started as an intern. After obtaining my degree from Minnesota State University, Mankato, I transitioned into a full-time role and have been with the company ever since. Now, I am a project engineer. I get involved with a project from the second it comes in the door. I create the estimate, work with the client to develop a work plan, and then schedule the work.
Municipal Water Leader: Would you tell us about the pipeline rehabilitation project you completed for International Paper Company’s Mansfield Mill?
