Like many engineering failures, the event was a result of several independent factors which fatefully came together at one time and led to a catastrophic failure – in this case, a centrifugal pump.
So, what happened?
The event happened during a daily routine pump start-up procedure. Shortly after the pump was started up, a manual valve in the pump discharge line broke and its disc was slammed by the pump pressure into a closed position. This sent a water hammer pressure wave back towards the pump discharge. The pump casing material is known to be susceptible to brittle fracture and the slurry pumps at the facility had a history of casing damage and leaks.
AFT Impulse was used to find the root cause
An independent water hammer study used AFT Impulse modeling. Results indicated that pressures at the pump could have been as high as ~100 bar (1400 psi) at the pump discharge flange. The pressure rating for the pump was 6.9 bar-g (100 psig).
Read the full story using the linked technical paper below. The paper details the process, the AFT Impulse analysis, and shows detailed images of the accident to help engineers understand how a casing was blown off a centrifugal pump.Read the Technical Paper