Aggressive soil conditions for buried pipelines can be an unforgiving environment for field-applied corrosion coatings. Soil stress along with pipe movement on girth welds can weaken coating performance and lead to failures, resulting in the need for corrosion repair work. To counter these stresses, it is crucial to identify coating options that are designed-to-perform in such environments. For a trusted coating solution on buried pipelines, there is a choice that’s engineered for success. Spoiler alert…. it’s not epoxy!!
Cold-applied, mesh-backed tape has a proven record for applications with aggressive soil stress conditions. To explain why the material offers superior resistance to soil stress, take an in-depth look at both the backing and the adhesive used on these tapes.
Image: Pipe running up the side of a hill showing obvious signs of wrinkling caused by soil stress on a film backed tape
The strength of mesh tapes stems from the mechanical properties of the woven fabric, typically polypropylene. Compared to traditional polyethylene film, polypropylene greatly increases tensile strength and reduces elongation of the tape backing. Normally, polypropylene would be too stiff to allow for easy application, but by utilizing a woven polypropylene material, the backing is more flexible. For a buried pipe, these properties prohibit the coating from stretching and wrinkling under soil stress which occur around both the pipe’s circumference and the longitudinal direction. This can help prevent coating failure due to pipe movement and soil stress.
What about the adhesive design? Can it help prevent coating failure? Absolutely!
Adhesives used on pipelines must be able to withstand excessive pipe movement plus hold up to the combined weight of the pipe and soil. Viscoelastic adhesives with strong cohesive strength combined with a polypropylene mesh backing, is the best way to maximize strength and flexibility.
When you consider the ease of application of mesh-backed applied tapes, along with the mechanical performance and anti-corrosion capabilities, you will find that a mesh-backed tape is your best solution.