INDUSTRY: Chemical Processing
APPLICATION: Filter Housing
A major chemical processing plant was experiencing problems with its filter housings and associated piping used in the manufacturing of zirconium.
In one of the process steps for the manufacturing of zirconium, they were combining sodium hydroxide with chlorine to produce sodium hypochlorite. Filtering systems were being used to remove chlorine from the gaseous stream generated during production. The chlorine gas would react with the moisture in the air to produce hydrochloric and hypochlorous acids that eventually corroded the steel pipe and filter housing beyond the point of structural integrity.
Yearly scheduled maintenance shut-downs required the removal and replacement of corroded chlorine piping sections as well as filter housings.
Maintenance engineers knew the trade off…specifying low cost mild steel as the material of construction would require yearly replacement and the constant battle with corrosion throughout the equipment’s useful life. And while stainless steel and other premium metals were found to be more corrosion resistant, they were prohibitively expensive. Even highly corrosion resistant liners were found to be inappropriate, fragile, or difficult to maintain.
SOLUTION: Impreglon 216
The solution to the problem came when Southwest Impreglon engineers recommended the application of their Impreglon 216 coating. A test section of approximately 50? of steel pipe and 1-filter housing vessel were internally coated with (30-40) mils thick of the Impreglon 216 coating. The coated test section was then installed and put back into service.
Coated Filter Housing Survives Acid Test
The test section of Southwest Impreglon coated pipe and filter housing were inspected after 6 months of service with no evidence of corrosion. The coating was subsequently inspected after 12 months, 18 months, and 24 months of service, and still no evidence of corrosion. From the initial date of installation and almost 4 yeras later, the equipment is still in service with little or no signs of corrosion.