In the early 2000’s, a Canadian Oil Sands facility was using knife gate valves to modulate slurry flow from their Primary Separation Cells.
When throttling a knife gate valve, the highest flow velocities (and wear) will occur within the acute angles formed at gate to body interface.
At that time, the service life of these heavy-duty valves was measured in days (typically 3 weeks). Upon failure, the system was shutdown, the knife gate valves were removed/discarded, and new units were installed.
These recurring expenditures in new valves and labor were significant; however they were minimal compared to the lost production revenue. The frequent shutdowns were costing the company millions annually. There had to be a better way…