Many times, the main causes of feed water recirculation valves failure is due to particulate in the flow stream. This particulate could be present due to improper blow techniques and installation that causes weld slag and other debris to become lodged in the inlet passages of today’s drilled hole and stacked disk designs. The presence of magnetite in the piping due to plant’s advanced age is also a very common cause of plugging.
Issue with plugging is a concern. Many times the particulates can pass through the inlet passage only to cause severe erosion damage to the throttling and shutoff surfaces of the valve trim, and valve ended up leaking/passing.
A leaking recirculation valves can cost a plant up to USD275,000 each year in lost capacity and maintenance costs.
Found a solution with Fisher Dirty Service Trim (DST) design. Check it out here on how this design solve your cavitation conditions while protects your shutoff surface, allowing flowing particulate up to 3/4" in diameter to pass through the valve : community.emerson.com/.../512.aspx