severe service
Wear in valves is surely an important concern for plant owners and operators . Eroded valve internals can have a longterm effect on the functioning and profitability of process facilities . Materials such as ceramic reinforced metals can be a good solution to increase component lifetimes in industries such as oil and gas , says Valmet ’ s Mr Jussi
Hellman .
By David Sear , Valve World
Managing wear in severe services
A ball valve for FCC bottom slurry control service : trim and changeable flowport liners made of solid MMC material .
Mr Hellman is a man with a mission . His goal is to help people like refinery owners to boost plant availability by increasing the lifetime of valve components . He does this be deploying Valmet ’ s deep knowledge of applying a whole range of materials in severe applications . Recently , for example , he spoke to this magazine about how to manage valve wear in fluid catalytic cracking ( FCC ) slurry oil service ( see Figure 1 ). “ FCC units are used in a refinery to convert heavy feedstock into lighter , more valuable products . Such units are especially valuable in refineries trying to maximize gasoline production over residual fuel oil . However , the catalysts required in this conversion process can cause problems as they have a tendency to accumulate in the bottom slurry , despite the use of settling tanks and / or filters . Such catalysts are erosive , causing challenges for items such as valves , pumps and piping ,” commences Mr Hellman . Mr Hellman therefore works with refineries to find the optimum materials solution . “ Complete elimination of wear is not always a realistic objective . Therefore , what happens when a worn valve is identified for replacement depends on the operating strategy of the plant owners as they look to increase availability targets . I therefore help them to assess tolerable wear rates , taking into consideration factors such as the expected future lifetime of the system , the cost of system repair or replacement , the costs of future interruptions in plant uptimes , the likelihood of valve jamming , etc .” Materials options that Mr Hellman can bring to the table include thermal spray coating , weld overlays , ceramic reinforced metal matrix composites ( MMC ), metal reinforced ceramic matrix composites ( CMC )
Fig . 1 : Representation of the fluid catalytic cracking process , with the fractionator bottom slurry valves highlighted . NB : This diagram was originally published in Valmet ’ s Fluid Catalytic Cracking application report and should not be viewed as an actual process flow diagram
22 Valve World August 2023 www . valve-world . net