Periodic Test and Maintenance Requirements
7�3
Partial-Stroke Test
The “Partial-Stroke Test” (“On-line”) can be performed to improve the PFD
AVG
value.
A typical partial-stroke value is 15% of the stroke.
The “Partial-Stroke Test” (“On line”) can be performed to satisfy PFD
AVG
(average
probability of failure on demand) value.
•
Recommended Test Interval = 1 to 3 months.
•
Procedure:
—
Operate the Actuator/Valve assembly for No 1 open/close cycles 15/20%
of the stroke.
—
Verify the Correct performing of partial-stroke operation (for example,
check locally, or automatically via Logic solver, or via the PST system the
correct movement of the actuator/valve till 15/20% of the stroke).
The above parameters to check will depend from the partial-stroke test system available.
Considering the application of the above described Partial-Stroke Test procedure, the
“Diagnostic Coverage” is >90 %.
7�4
Proof Test and Periodic Maintenance
We advise to perform the following checks upon each proof test interval complying with
the rules and regulations of the country of final installation:
•
Visually check the entire actuator as well as the control system (where foreseen).
•
Ensure there are no leaks on the actuator parts under pressure.
•
Check pneumatic connections for leaks. Tighten tube fittings as required.
•
Check if manual override (where foreseen) is regular.
•
Check if pneumatic filter cartridge (where foreseen) is sound and filter bowl (where
foreseen) has been cleaned properly.
•
Check the setting of the relief valves (where foreseen).
•
Verify that the power fluid supply pressure value is within the required range.
•
Remove built-up dust and dirt from all actuator surfaces.
•
Inspect actuator paint work for damages to ensure continued corrosion protection.
Touch-up as required in accordance with the applicable paint specification.
•
Operate the Actuator/Valve assembly for No 2 open/close complete cycles with
complete closing of the valve.
•
Verify the correct performing of open – close operations (for example, check
locally, or automatically via Logic solver, the correct movement of the actuator).
The Installation, Operation and Maintenance manual defines a minimum maintenance
interval after 500.000 cycles for the EL-O-Matic E and P Series actuators. This addresses
components that may have age related degradation. When the maintenance interval has
elapsed a complete overhaul of the actuator is required.
9
April 2017
SIL Safety Manual
DOC.SILM.EEP.EN Rev. 0
Section 7: Periodic Test and Maintenance Requirements
