Refurbish and protect a venturi from a sea-water, condensate water system. The component illustrated cavitation and undercutting damage, with severe corrosion around the flange area.
Corrocoat EA/EB, Fluiglide E & Plasmet ZF
Grit blasted internally to ISO 8501-1 cleanliness standard SA 2 1/2. Grit blasted externally to ISO 8501-1 cleanliness standard SA 2. Applied internally Corrocoat EA / EB to achieve a minimum dft of 2.0mm followed by a top coat of Fluiglide E. Applied externally 2 coats of Plasmet ZF followed by a cosmetic top coat.
Corrocoat’s EA and EB series provide a high build flexibilised epoxy system with good resistance to erosion, cavitation and impact, when used at thicknesses above 1.5mm. Originally these components were glass lined. Corrocoat can either repair, or completely refurbish Glass lined components – depending on the level of damage, and the environment in which they are operating. The use of glass-flake linings, specially manufactured for their cavitation, erosion and impact resistance offers an excellent alternative to glass and other linings – subject to the environmental conditions being within the specification of the glass-flake lining. Glass frit lining can be expensive and time consuming due to the subsequent stoving required. The additional process steps required in glass frit lining also negates the possibility of on site application or repair if required. Glassflake linings can be applied and repaired on site.
The venturi on arrival in our Leeds works
Severe undercutting & cavitation damage in the flange area
Completed repair and refurbishment and awaiting packing and despatch to customer
Prepare screens by pressure washing, manual cleaning & scraping, then abrasive blasting to remove marine growth, debris and corrosion deposits. Assess repair work. Apply corrosion protection and Biofoul.
Corroglass 600 Series for repair and re-profiling, with a Polyglass PPA primer coat. Top coat of Biofoul applied for anti-fouling requirements.
Grit blast whole structure to ISO 8501-1, cleanliness standard SA 2 1/2 with minimum surface profile of 50μm. Apply Polyglass PPA to whole structure as a primer for the Corroglass 600 Series, applied to a min. dft of 1.5mm. Apply top coat of Biofoul.
Biofoul is an eco-friendly non-toxic coating. The mechanism by which Biofoul provides anti-foulin properties enables the product to be used in both static and self-polishing environments. The coating is mechanically strong (unlike many self-polishing anti-foulants), has a long life (when used in conjunction with a Corrocoat corrosion system) and is non-toxic. By applying a final coat of Biofoul, the Power Station has eliminated the costly requirement for regular cleaning & maintenance by divers. In addition to this replacing these screens would have cost considerably more than re-profiling and protecting by Corrocoat.
The screen after pressure washing – showing the extent of corrosion and pitting
Detail of the re-profiled cross-members
The completed screens awaiting despatch