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| ESDV ACTUATOR |
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| PSDV ACTUATOR |
PSD is defined as the automatic isolation and the activation
of all part of a process. During a PSD the process remain pressurized,
Basically PSD consist of field mounted sensors. Valves and trip relays, a system
logic unit for processing of incoming signals, alarm and MHI units. The system
is able to process all input signals and activating output in accordance with
the applicable cause and effect matrix chart
Typical action from PSD systems are:
1.
Shutdown the whole process
2.
Shutdown part of the process
3.
Depressurize/Blow down parts of the process
The emergency shutdown (ESD) is shutdown to minimize the
consequences during emergency. ESD can be automatically initiated by load shedding
functions or manually by the operator through push button on the panel. ESD
will shutdown an isolate all designated process related equipment, including
inlet and outlet ESD valves. Depends on each project some plant will allow the
power generation, utilities and fuel gas system keep running during this
condition.
