How to improve valve service life in Catalyst Cracking Units
N & C American Market Area Business Manager
A catalyst, by definition, is a substance that enhances a chemical reaction. In the refining industry, catalysts are extensively used in many upgrading processes. One common upgrading process in refineries is the Fluid Catalytic Cracking unit (FCC) unit, which converts heavier distillation cuts into lighter, more profitable products, such as gasoline. This unit has many severe service valve applications that require special attention to design and material selection.
One such application that is historically considered “high maintenance” is the oil slurry control valve in the bottoms circuit. The catalyst used in the FCC is very small in size, but, over time, this catalyst breaks down to an even smaller size particulate and eventually makes its way to the slurry oil. These fine particles, often referred to as cat fines, are very dense and abrasive and can quickly erode conventional valve trim.
Erosion-resistant valve design can improve the reliability of an FCC unit
An FCC unit typically operates for five years between turnarounds. Erosion is relatively benign during the first three years after a turnaround; however, the last two years can be very erosive, due to the accumulation of catalyst fines. Typical control valves in the bottoms circuit are rotary eccentric plug or V-ball control valves. During the last two years of an FCC run, these valves can fail within six months. Replacing these valves forces the FCC to shut down and/or to operate in an unsafe condition. As valve reliability can be one of the most important cost factors impacting FCC profitability, reliability can often override cost considerations. In these extreme erosive cases, Neles has successfully replaced existing rotary control valves with a fully ceramic-lined ball control valve.
All ceramic wetted parts, ensuring the best possible erosion resistance.
Special zirconia grade offers impact resistance exceeding most other ceramics
Excellent thermal shock resistance
Proven reliability – Neles has numerous installations in high-abrasion applications showing significant service life improvements
Same take-out dimensions as existing rotary control – ease of replacement, no piping modifications needed
Costs associated with valve replacement in an FCC unit can be particularly high, as these valves can range from 2”-10” in size. However, we have found refineries to be pleased with both the elimination of frequent valve replacement costs and the dramatic improvements in FCC unit uptime and process throughput – all of which went directly to the unit’s bottom line.
Tailored performance with new materials
Neles' metal matrix composite (MMC) materials are another key innovation in the field of wear protection. The superior hardness of ceramics and the toughness of metals are incorporated into our metal matrix composite materials, which thus offer the best combination of wear resistance and mechanical reliability. The Neles MMC materials are available in WearBlock™ bi-metal valves, but also as an option (hybrid-E) for ceramic insert parts in our ceramic ball valves. Your valve performance can be tailored to align with your service and maintenance strategy. Balancing out process requirements, planned maintenance schedules and lifecycle costs, Neles can help you select the valve solutions that work best for you. By pairing your valves with Neles' smart devices, you can monitor valve condition and performance in real time, allowing for well-planned maintenance and service operations without any nasty surprises.
Want to know more about Neles’ valve solutions for Fluid Catalytic Cracking applications? Follow this link
Neles series E ball control valves are designed to meet the most severe erosive service requirements of wide range of industrial applications in pulp & paper, petro-chemical, refining and related industries. E series valves using new generation ceramic material lined flow path and trim parts are suitable for highly abrasive rotary control applications. Ceramic valves enable to extend the plant process availability and lower the maintenance costs.
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A short article looking at the sound reasoning for using advanced slurry valves in a number of industries where targeted efficiencies and productivities require process parameters that may seem totally intolerable for materials and construction – namely nonstop exposure to abrasive and erosive solids that often move at very high velocities.