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Local Fuel PLC –The Shoreham Oil Terminal
Safety Instrument System LFS-SIS1 - Operation, Maintenance and Modification Lifecycle
P & I Design Ltd
DOCUMENT NO: LF364013_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: B DATE: 16.05.16
Tel: + 44 (0)1642 617444
PAGE 10 OF 11
Fax: + 44 (0)1642 616447
www.pidesign.co.uk8
SCHEDULING
Frequency
Test Reference
Prior to
Proof
Testing
12 Monthly
60 Monthly
Following
System Fault
or Activation
Modification
LF364011_RPT - LFS-SIS1
Documentation Verification
*
LF364012_RPT - LFS-SIS1
Shutdown Conditions Proof
Testing
*
Physical testing of
SENSING ELEMENTS
Stage 4 Functional Safety
Assessment
Stage 5 Functional Safety
Assessment
LF364013_RPT - LFS-SIS1
Operation, Maintenance and
Modification Lifecycle
LF364004_SCH - LFS-SIS1
Testing Lifecycle Matrix
*
Testing required if any part of the system disturbed, replaced or maintained outside of the
above schedule. *As required following review of fault/ activation.
The Safe Fail Fraction of the Drexelbrook level switch is 93%. Thus as a worst case, if all
dangerous undetected failures are not detected during the annual test, the proof test coverage
can be assumed as 93%. For this case, the following graph shows that the PFD
calc
for the
system remains acceptable (below 5 x 10
-3
) for at least 8 years.