Revamps 2026 Issue

Avoid corrosion failures in refinery process equipment

High-velocity thermal spray alloy cladding mitigates corrosion in ammonia scrubbers and amine columns, improving asset integrity and reducing lifecycle costs

Shinji Masuzaki Integrated Global Services (IGS)

C orrosion-induced degradation in refinery process equipment remains a key challenge, particularly in ageing assets operating under constrained mainte - nance schedules. This study investigates the application of the proprietary High Velocity Thermal Spray (HVTS) alloy cladding as an advanced corrosion mitigation technology. Its technical characteristics are examined in comparison with other repair methods, including weld overlay (WOL) and traditional thermal spray coatings. Two case studies are presented: u Application of advanced corrosion mitigation technology in a Japanese refinery ammonia scrubber with repeated previous coating failures. v A comparative evaluation of advanced corrosion mitiga - tion technology and conventional thermal spray technol - ogies in amine process columns under identical operating conditions. Results from field applications indicate this advanced alloy cladding provides a dense, low-permeability coating with high adhesion strength, enabling long-term corrosion protection while minimising operational disruption. The findings, based on field applications in Japanese refinery environments, suggest that advanced alloy cladding tech - nology, with its thin coating, higher bond strength, and minimal distortion effect, is a suitable solution for improv - ing asset integrity and reducing lifecycle costs. Ageing infrastructure Refinery and petrochemical facilities in Japan are increas - ingly affected by ageing infrastructure, stringent safety requirements, and limited maintenance windows. Critical equipment, including pressure vessels, towers, and col - umns, operates under corrosive environments involv - ing high temperatures, acid gases, and multiphase flow conditions. Corrosion in such environments leads to metal wastage, wall thinning, and potential loss of structural integrity, which may result in unplanned shutdowns and associated economic impact. To mitigate these risks, a range of repair and protection technologies is applied in industry. WOL remains a well-established and widely adopted solution, particularly when restoring wall thickness and provid - ing structural reinforcement are required. Thermal spray

technologies have also been utilised to provide corro - sion-resistant barriers with reduced thermal impact on the substrate. The selection of an appropriate repair method depends on several factors, including the extent of material degra - dation, operating conditions, equipment geometry, and available maintenance duration. In this context, this alloy cladding technology represents an approach designed to provide a dense, corrosion-resistant barrier while enabling efficient application under constrained conditions. The technical characteristics of alloy cladding advance - ments are further discussed within the context of existing repair methodologies, evaluating performance through selected field applications. Attention is given to the role of engineering-based decision-making in selecting appro - priate materials and application methods to support long- term asset integrity. Corrosion in refinery process equipment is driven by chemical composition, temperature, and flow conditions. In amine systems, corrosion mechanisms include carbonic acid formation, acid gas contamination, and localised con - densation effects. These mechanisms contribute to local - ised pitting and general wall thinning. If the corrosion allowance is exceeded, operators must undertake major repairs or equipment replacement, often within constrained turnaround periods. Conventional repair methods WOL is a widely accepted method for corrosion miti - gation in refinery process equipment. By depositing a corrosion-resistant alloy (CRA) through welding, a metal - lurgically bonded layer is formed, which can both restore wall thickness and provide long-term corrosion resistance. This method is particularly suitable in situations where: • Wall thickness has fallen below the minimum allowable limit. • Structural reinforcement is required in addition to corro - sion protection. • Sufficient time is available during shutdown for con - trolled application and any required post-weld heat treat - ment (PWHT). WOL has demonstrated reliable long-term performance in many applications. However, it typically involves relatively

Revamps 2026