The internal surface of these silencers have been experiencing corrosion and abrasion due to gushing high pressure gases along with abrasive dust particles. At lot of places over the surface large number of pits have been observed alongside loss of metal in the form of metal flakes.
After disengaging the silencer from it’s operational position, the surface inside the silencer was examined thoroughly and surface preparation works were implemented. Initially the surface was scrubbed using cleaning agents & water washed to eliminate the presence of chemical containments. Once the surface has dried, a first round of copper slag blast cleaning was carried out followed up with detergent scrubbing & water washing again. The entire surface was blast cleaned again using chilled iron grit to attain the desired surface roughness, ensuring a surface profile of Sa 3 Swedish Standards.
Coating was applied all over the prepared surface using nylon rollers and brushes to the recommended thickness. Deposition of essential thickness was cross-checked using the Elcometer WFT Gauge. Once the coating was cured, Dry Film Thickness was measured to make sure the applied coating had been developed which corresponds to the Wet Film Coating Thickness. Holiday Spark Testing was performed to ensure complete coating integrity.
Adhering to all the quality standard methods the application of coating inside the silencer tank was completed. On completion of the application task inside the tank internal, similarly external surface of the silencer tank was also coated in the same way, to protect it from the external chemical exposure and moist working conditions.