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Company Advisories |
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Company Advisories | ||
CA - 07 - Ice Storm Solenoid Latch FailureSevere weather can impact the performance of
controls in general and safety instrumented systems specifically.
In areas where severe weather is not common, the effect can be quite
dangerous. This advisory presents an example of where an ice
storm in the mid-west resulted in dangerous failures (common cause)
of all valves with solenoids with manual reset latches. CA - 06 - Instrument Air Pressure Safety IssuesInstrument air systems are an important but often
overlooked component in a safety instrumented system. The lack
of attention is primarily caused by the inherently safer design of
most systems which go to the safe state upon loss of instrument air
pressure. While not extremely common, instrument air systems
can cause dangerous failures of SIS if not properly designed and
operated. This advisory presents an example of how increasing
the instrument air header pressure caused most of the shutoff valves
in the plant to fail in a dangerous state. A sobering reminder
of the importance of utilities and the reality of common cause
failures.
CA - 05 - Breakdown Maintenance Not Allowed by OSHAIn order to have an effective program for
mechanical integrity of safety instrumented systems it is essential
that equipment is only employed during its "useful life". Some
operating companies current practices do not include replacement of
'shorter' useful life components, such as solenoid valves, until the
device fails. Operating companies should consider modifying
their programs to ensure that these devices are replaced
before they fail, based on compliance guidance from OSHA. CA - 04 - Continuous vs. Demand Mode Safety Instrumented FunctionsThe most recent edition the ANSI/ISA
S84.00.01-2004, Functional Safety: Safety Instrumented Systems for
the Process Industry Sector, establishes alternative design
procedures for Safety Instrumented Systems (SIS) depending on the
expected frequency of a demand condition being placed on a Safety
Instrumented Function, or SIF. Designers of Safety Instrumented
Systems refer to these different applications as either Continuous
Mode or Demand Mode SIF. CA - 03 - Coker Safety InitiativeA number of refinery have undertaken initiatives to improve the safety of Coker operations. These initiatives have also been closely followed by regulators who have also issues guidance documents that highlight the hazards of Coker operation and provide recommendations for improving their safety... CA - 02 - Instrumentation and Control Mechanical Integrity ProgramsThere has recently been a large amount of interest in the mechanical integrity programs that are employed for instrumentation and control systems at refineries and chemicals plants. The focus of these reviews has been to ensure that all instrumentation is covered under an appropriate testing and maintenance program, and that these programs are consistent from site to site... CA - 01 - EPA Risk Management Plan Update and ResubmissionIn 1999, over 14,000 industrial sites were required to submit Risk Management Plans to the Environmental Protection Agency. These plans are required to be updated every five years, and the five year anniversary of the first submissions falls on June 21, 2004, only a few months away...
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