Emerson Bettis CBB Series - Operational Test Procedures

October 2015
Service Instructions
VA001-196-30 Rev. 1
23
Section 5: Troubleshooting
Troubleshooting
5�2 Operational Test
5�2�1 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 stroke test frequencies will be
denedbythenalinstallertoachievethedenedSILlevel.
5�2�1�1 Procedure
5�2�1�1�1 Stroke the actuator/valve assembly two complete open/close
cycles with complete closing of the valve.
5�2�1�1�2 Verify the open/close cycles functioned correctly (e.g., check
locally, or automatically via logic solver, the correct movement
of the actuator/valve).
5�2�1�1�3 Upon successful completion of the above described full stroke
test procedure, the “test coverage” can be considered 99%.
5�2�2 Partial Stroke Test (when requested)
The “Partial Stroke Test” (“On-line”) can be performed to improve the PFD
AVG
value
and to satisfy PFD
AVG
(average probability of failure on demand) value. A typical
partial stroke value is 15% of the stroke and the recommended test interval is
about every one to three months.
5�2�2�1 Procedure
5�2�2�1�1 Operatetheactuator/valveassemblyforNo°1open/close
cycles 15% of the stroke.
5�2�2�1�2 Verify the partial stroke test functioned correctly (e.g. check
locally, or automatically via Logic solver, or via the PST system
the correct movement of the actuator/valve was 15% of the
stroke).
NOTE:
The above test is only applicable on systems equipped with a partial stroke feature.