9
September 2018
SIL Safety Manual
DOC.SILM.EF.EN Rev. 1
Periodic Test and Maintenance Requirements
Section 8: Periodic Test and
Maintenance Requirements
8.1 General
Please consider that the information in this paragraph are relevant only in regards of
Reliability Tests; please refer to the Installation, Operation and Maintenance manual for
detailed information about product maintenance, handling and storage. Diagnostic tests
may be made to increase the system reliability (Full-Stroke or Partial-Stroke Test). “On site”
tests depend on Project/Plant facilities requirements; however, a functional test must be
executed on site, prior actuator operation.
8.2 Full-Stroke Test
The “Full Stroke Test” (“On-line”) must be performed to satisfy the PFD
AVG
(average probability of failure on demand) value.
The full test frequencies will be dened by the nal integrator in relation to the dened
PFD
AVG
to be achieved.
• Procedure:
– Operate the Actuator/Valve assembly for 2 complete open/close cycles
with complete closing of the valve.
– Verify the Correct performing of open – close manoeuvre and within the
required operating times (eg. check locally, or automatically via Logic
solver, the correct movement of the actuator/valve).
– Compare the results with the ones stored during SAT
(site acceptance test) activities.
– Record the test results in your company’s SIF
(safety instrumented function) database.
– Restore normal operation.
Considering the application of the above described Full Stroke Test procedure, the “Test
Coverage”, in case of automatic procedure, can be considered > 99%.
In case of manual procedure the “Test Coverage” shall take into account also the test
imperfection and the reliability/competence of the operator.
Section 8: Periodic Test and Maintenance Requirements
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