Flowserve LPS Series Heavy-Duty Actuators - Manual (Page 5)

6.4 Proof Test and Periodic Maintenance
We advise to perform the following checks upon each proof
test interval, complying with rules and regulations of the
final installation country:
• Visually check the entire actuator as well as the control
groups, if any.
• Ensure there are no leaks on the actuator parts under
pressure.
• Check pneumatic connections for leaks. Tighten pipe
fittings, as required.
• Check if the quick exhaust valves (if any) have been
cleaned properly.
• Check if the (hydraulic) manual override is regular.
• Check if the suction and exhaust cylinder filters have been
cleaned properly.
• Check the setting of the relief valves.
• 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 an open/close
complete cycle with complete closing of the valve.
• Verify the correct performing of open – close manoeuvre
(e.g. check locally, or automatically via Logic solver, the
correct movement of the actuator/valve).
We advise to perform the following periodic maintenance:
• Replace the seals on the parts under pressure every
five years.
• Check all components subject to wear (bushings,
coupling mechanisms).
7 Hardware Fault Tolerance
The HFT (Hardware Fault Tolerance) of the device is 0.
According to Tab.6 of IEC 61511-1, the requirements
of minimum hardware fault tolerance (HFT) have to be
observed, but, as long as an assessment report, fully in
compliance with IEC 61508 part 1 to7, has been performed,
alternative fault tolerance requirements have to be
considered applicable, according to Table 2 of IEC 61508-2,
as per par. 11.4.5 of IEC 61511-1.
8 Classification
The device is classified as Type A, according to IEC 61508-2.
9 Safe Failure Fraction
SFF (Safe Failure Fraction) = 0% without external
diagnostic tests.
SFF > 0 with external diagnostic tests, carried out according
to definition 3.8.7 of IEC 61508-4.
• SFF = 91% with Partial Stroke Test.
• SFF = 99% with Full Stroke Test.
The SFF shall be evaluated for the entire final element
sub-system.
The diagnostic test shall be performed considerably more
often than the demand of the safety function.
10 Mean Repair Time
The MRT (Mean Repair Time) of the device is 24 hours.
NOTE: The MRT is estimated considering availability of
skilled personnel for maintenance, spare parts, adequate
tools and materials on site (i.e., it encompasses the effective
time to repair and the time before the component is put back
into operation).
11 Systematic Capability
The systematic capability of the device is 3.
This systematic capability is guaranteed only if the user:
1. Use the device according to the instructions for use
and according to the present Manual.
2. Use the device in the appropriate environment
(limitation of use).
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LPS Series Heavy-Duty Actuators FCD LPS-SM-00 – 1/14