Addressing the Problem of Repeated Plant Accidents at Process Pumps

Despite many publications drawing attention to recurring accidents in process plant these continue and in some cases result in very large losses. This paper discusses three separate refinery accidents related to pump operation

1)      A fatal accident which occurred when a motor operated valve was opened during pump maintenance

2)      A fatal accident when a maintenance drain was opened in an attempt to manage an operating problem during start-up

3)      A fire during start-up when a maintenance drain was left open following plant revamp

These past accidents are related to two of the largest refinery losses in 2012 which involved the release and ignition of vapour clouds around pumps. In each case it is shown that the potential hazard caused by vapour cloud release could have been recognized during HAZOP study and procedures recommended which could have prevented the occurrences. Understanding which risk controls have failed and why they failed is essential if effective prevention measures are be taken. But equally important is the sharing of this information across the industry to those involved in safety studies during plant engineering, operation and maintenance.