Mechanical Protection vs. Corrosion Protection: Why Both Are Essential for Pipeline Integrity

Traditional pipeline coatings are primarily designed to provide corrosion protection.

Coatings such as Fusion Bonded Epoxy (FBE), 3LPE, 3LPP, and liquid epoxy coatings act as barriers that prevent moisture, chemicals, and corrosive elements from reaching the steel pipe. These coatings are often used together with cathodic protection systems to minimise corrosion throughout the pipeline’s service life.

However, corrosion protection alone is not enough, particularly for Horizontal Directional Drilling (HDD) installations. While many corrosion barrier prevention coatings meet industry requirements for pipeline integrity, they often lack the mechanical properties needed to withstand the stresses encountered during pullback operations. Abrasion, impacts, gouging, bending forces, and contact with rocks or drilling equipment can damage the coating, exposing the steel beneath. Once the coating is compromised, its corrosion-protection function is significantly reduced.

This is where mechanical protection becomes important.

Mechanical protection is designed to protect the corrosion barrier coating from physical damage during installation. This use of composite abrasion-resistant overlay (AROs), such as Scar-Guard, provides additional resistance to abrasion, impact, shearing, tearing, and cracking. Industry testing shows that composite materials are significantly stronger, stiffer, and more fracture-resistant than traditional epoxy coatings, making them better suited to HDD environments.

The relationship between the two types of protection can be summarised as follows:

  • Corrosion protection prevents electro-chemical and environmental degradation of the steel pipe during operation.
  • Mechanical protection prevents physical damage to the corrosion-protection coating during installation and pullback.
  • If mechanical damage occurs, the corrosion barrier coating may fail, leaving the steel vulnerable to corrosion and reducing the overall integrity of the pipeline.
  • Therefore, both forms of protection work together to ensure long-term pipeline reliability, reduce maintenance costs, avoid costly reinstallation, and maintain asset integrity.

Key takeaway: Corrosion protection safeguards the pipeline against environmental attack throughout its service life, while mechanical protection preserves that corrosion barrier during demanding HDD installation activities. Long-term pipeline integrity depends on both systems working together.

Related Solution

ScarGuard is a composite abrasion-resistant overcoat (ARO) designed to provide mechanical protection for field joint and mainline coatings during HDD, trenchless and challenging pipeline installations.

Learn more about ScarGuard →