TROUBLESHOOTING
PROCESS OPERATIONS
Alarms and Trips
ALARMS AND TRIPS
An upset on a process unit can cause a shutdown if prompt, corrective action
is not taken.
Even worse is the possibility that the unit may self-destruct if an abnormal
condition is allowed to continue.
An alarm alerts the operators that something has gone awry in the process.
A trip shuts down an endangered piece of equipment when it is too late for
human intervention.
When a trip fails to function, severe damage to a process unit can result.
ALARMS AND TRIPS
Steam Turbine Trips
During the Nazi invasion of Russia in World War II, Soviet engineers were
instructed to destroy turbogenerators before retreating.
First, the trip mechancism was wired so that stay latched.
Next, the turbine was run up to maximum speed.
Finally, the pump circulating lube oil to the turbine bearings was shut off.
Kaboom!!!!
ALARMS AND TRIPS
Such a sequence of similar events can occur accidently, and the process
industry has a significant history of major equipment failures because of them.
Trip Mechanism
