Withstanding abrasive crushed coke
The instrumentation and electrical (I&E) shop at a nitrogen fertilizer plant found it necessary to repeatedly replace a 3” ceramic segment valve used in its coke gasification unit. The highly abrasive media of crushed coke in water along with residual carbon fines, chromium and ash would routinely wear holes in the valve bodies every two months. The plant looked for ways to turn the valve erosion maintenance costs into profit.
Valve failure creates huge costs
This constant valve failure meant the plant had to buy a EUR 1,800 replacement valve every two months at an annual hardware cost of EUR 11,000. The costs due to plant downtime were even higher. Every time the process had to be shut down to replace one of these valves, it cost about EUR 7,275 in lost productivity or EUR 44,000. The labor required to replace a valve added another EUR 725 per replacement. Added together, the total cost of replacing this valve every two months for an entire year was EUR 59,000.
Advanced ceramics resist abrasion
To improve its uptime, the plant chose to utilize the full ceramic ball valve. The advantage of this type of a valve is that the entire flow path and trim of the valve is made from an advanced ceramic material. This material has proven to effectively resist some of the most abrasive industrial media, including lime mud, metal slurries, titanium dioxide and cement. Not surprisingly, the advanced ceramic material also proved effective with the abrasive media at this particular fertilizer plant.
In addition to effectively resisting abrasion, the 3” Ceramic Ball Valve ensured optimal flow characteristics for the process in question as a result of using Metso’s Nelprof® valve sizing software.
Extended life cycle creates cost savings
The plant eventually purchased and installed two ceramic ball valves. The first of these replacement valves allowed the plant to stay online continuously for two years, meaning the plant avoided more than EUR 109,000 in replacement and downtime costs.
The second ceramic ball valve was then installed and lasted four years, which was 24 times longer than the original solution. In all, this second valve saved the nitrogen fertilizer plant more than EUR 218,000 over the four-year period.
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