Do not depend on remotely operated valves for isolation for maintenance work

The two incidents below highlight the fact that you should not depend on rmotely operated valves for isolation during maintenance activities. ROV's are meant for use only during emergencies to prevent a major loss of primary containment:

1. A bolted joint was opened for maintenance on a pump but reliance for isolation was placed on a remotely actuated valve. The valve was inadvertently opened either from the control room or from the motor control centre resulting in a major release of flammable gas, with subsequent explosion.
   
2. A fire occurred during the removal of a blind. The blind was located downstream of an air actuated valve which was inadvertently opened during blind removal. This released flammable liquid, resulting in a large fire and multiple fatalities.