Corrocoat Partner – Corroserve (UK)
The Industry – Oil and Gas
The Challenge – At the request of the client – Centrica, Corroserve carried out an inspection report on the fuel gas knockout vessel at a UK onshore gas terminal. The vessel showed external corrosion to all nozzles and heavy damage and corrosion to the internal lining in several areas. Once received at Corroserve’s Leeds works, it was determined that the failure of the coating was due to poor surface preparation as there was little or no surface profile. Corroserve was advised that the internal coating system would be subject to gas saturated with water containing CO2, residual natural gas at a maximum operating pressure of 4.8Barg and a temperature of 45°C..
The Solution – Corroserve offered a solution comprising: surface preparation, application of a Polyglass VEF coating system and surface testing. The nozzles and plate were pre-machined/rebated to prepare the faces for coating application. The internal substrate was then abrasive blasted to remove the existing coating system and prepare the surface, carried out to ISO 8501-1 SA 2½ to achieve a minimum surface profile of 50µm.
Polyglass VEF was specified to all internal surfaces of the vessel – applied by hand and airless spray to achieve a minimum DFT of 1250µm. Spark testing ensured the coating was free from holidays and pin holes. The external surfaces were also abrasive blasted and two coats of Plasmet ZF applied with a final cosmetic topcoat of Corrothane AP1.
Results & Benefits – The Polyglass VEF coating system offers excellent corrosion protection in immersed and non-immersed environments, providing superior resistance to chemicals across the full pH range, solvents and gases.