HSSE Management Tours - BG Group

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Key Integrity Barriers
Topic 16 – Emergency Shutdown (ESD)
and Blowdown Systems
• Emergency shutdown systems are installed on
plants to provide a mechanism to shut down the
plant safely in the event of an emergency. ESD is
usually triggered automatically if some key process
parameter has been exceeded or a fire/gas release
has been detected, or may be manually initiated if
personnel believe that they are no longer able to
ensure safe control of the plant.
• Blowdown systems provide a means to rapidly
depressurise the plant by removing the gas
inventory to a safe location (e.g. a flare).
• These systems are required to be functional when
called upon to take action. In order to do this
end-to-end tests of the systems (including sensors,
control system and final control elements) have to
be conducted periodically to ensure that the system
is robust and ready to respond if/when required.
HSSE Management Tours:
Asset Integrity Guide
• The key areas in ensuring ESD and blowdown
system functionality are:
– A robust process(s) for system function testing of
all components
– Ensuring that function tests are actually carried
out and the results recorded for analysis
– Review of results and follow up on any
deficiencies found
• Certain testing activities may require one or a
number of devices to be isolated, and it is therefore
important to fully understand what functions are
being withdrawn in this period and that any risks
are fully assessed.
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