AUMA SAR 07.2 - Internal Actuator Monitoring with Control Via Standard Controls; Partial Valve Stroke Test (PVST): Execute; Safety Equipment: Check; Tests and Maintenance

8. Tests and maintenance
Test and maintenance tasks may only be performed by authorised personnel who
have been trained on functional safety.
Test and maintenance equipment has to be calibrated.
Information Any test/maintenance must be recorded in a test/maintenance report.
Impact of testing/maintenance on relevant devices, equipment or other work must
be evaluated.
8.1. Safety equipment: check
All safety functions within a safety equipment must be checked for perfect functionality
and safety at appropriate intervals.The intervals for safety equipment checks are to
be defined by the plant operator.
The plant operator has to establish a safety planning for the entire safety lifecycle
of the SIS. Policies and strategies for achieving safety as well as different activities
during the safety life cycle should be defined.
8.2. Internal actuator monitoring with control via standard controls
The device, consisting of actuator with actuator controls and integral SIL module has
an internal actuator monitoring. By controlling standard controls/actuator via standard
operation commands, internal actuator monitoring is automatically performed. Internal
actuator monitoring identifies most of the safety-related actuator components. If a
fault occurs, the fault would be signalled via the output contact of the SIL module
(SIL failure).
To ensure the safety figures of the Safe ESD safety function, the device has to be
controlled at least once per month via the standard controls, including output contact
assessment of the SIL module (SIL failure). If it cannot be ensured that the
device is controlled by the standard controls at least once per month, a <Partial Valve
Stroke Test (PVST)> has to be performed instead.
The control signal and the pertaining operation of the actuator have to be present
for at least 4 seconds. If control signal and pertaining operation of the actuator are
present for at least 4 seconds without signalling a fault via the SIL output contact
(SIL module: SIL failure), the test was successful. Otherwise, the device has
to be checked in accordance with the steps in the <Proof test: execute> chapter.
8.3. Partial Valve Stroke Test (PVST): execute
— Option —
There are two options for performing the PVST.
1.
Performing the PVST using safe inputs Safe ESDa and Safe ESDb:
The PVST must be controlled by the external safety PLC.The safety PLC uses
safe inputs Safe ESDa and Safe ESDb. Desired diagnostics is performed
by evaluating the SIL output contact (SIL module:SIL failure). Both control
signals and related actuator operation have to be present for at least 4 seconds.
The test is successfully passed if both control signals and the pertaining actu-
ator operation are present for at least 4 seconds without fault signal from the
SIL output contact (SIL module: SIL failure). Otherwise, the device has
to be checked in accordance with the steps indicated in the <Proof test: execute>
chapter.
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Multi-turn actuators
SA 07.2 – SA 16.2/SAR 07.2 – SAR 16.2 Tests and maintenance